ArticlePDF Available

Chemical Composition, Fatty Acids Content and Glycemic Index of Two Different Types of Omani Halwa

Authors:

Abstract and Figures

The study evaluated the chemical composition, fatty acids contents, and glycemic index (GI) of two different types (white and black) of Omani halwa. Representative samples of Omani halwa were collected from the local market. The proximate composition and energy contents of white and black halwa did not vary significantly (P < 0.05). The percentage moisture, crude protein, total fat, ash, crude fiber, and nitrogen free extract (NFE) in white and black halwa were 11.8 and 12.1, 0.28 and 0.44, 13.8 and 12.4 and, 0.01 and 0.02, 0.15 and 0.05, and 74.0 and 75.0 respectively. The energy values in white and black halwa were 421.3 and 413.4 kcal/100 g respectively. No significant (P < 0.05) differences were observed in the total fatty acids, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), and polyunsaturated fatty acids (PUFA) content in both types of Omani halwa. The SFA were present in highest concentration. The proportionate percentages of SFA, MUFA and PUFA in white and black halwa were 64.57% and 65.47%; 31.28% and 30.79%; and 4.11% and 3.74% respectively. The average GI and GL values for white and black halwa also did not vary (P < 0.05) and were 54.8 and 52.0 and 14 and 13.4 respectively. Although the glycemic index values of Omani halwa fall in low GI category (< 55), it should be consumed with caution because of its high fat, in particular of SFA and high sugar contents.
Content may be subject to copyright.
Pakistan Journal of Nutrition 12 (8): 753-760, 2013
ISSN 1680-5194
© Asian Network for Scientific Information, 2013
Corresponding Author: Amanat Ali, Department of Food Science and Nutrition, College of Agricultural and Marine Sciences, Sultan
Qaboos University, P.O. Box 34, Al-Khoud 123, Sultanate of Oman
753
Chemical Composition, Fatty Acids Content and Glycemic
Index of Two Different Types of Omani Halwa
Amanat Ali , Khalid M. Al-Zuhaibi , Mostafa I. Waly , Ahmed A. Al-Alawi ,
1 1 1 1
Jamal N. Al-Sabahi and Devarajan Sankar
2 1,3
Department of Food Science and Nutrition, Department of Crop Sciences,
1 2
College of Agricultural and Marine Sciences, Sultan Qaboos University,
P.O. Box 34, Al-Khoud 123, Muscat, Sultanate of Oman
Department of Cardiovascular Diseases, Fukuoka University, Fukuoka, Japan
3
Abstract: The study evaluated the chemical composition, fatty acids contents and Glycemic Index (GI) of two
different types (white and black) of Omani halwa. Representative samples of Omani halwa were collected
from the local market. The proximate composition and energy contents of white and black halwa did not vary
significantly (p<0.05). The percentage moisture, crude protein, total fat, ash, crude fiber and Nitrogen Free
Extract (NFE) in white and black halwa were 11.8 and 12.1; 0.28 and 0.44; 13.8 and 12.4; 0.01 and 0.02; 0.15
and 0.05 and 74.0 and 75.0, respectively. The energy values in white and black halwa were 421.3 and 413.4
kcal/100 g, respectively. No significant (p<0.05) differences were observed in the total fatty acids, Saturated
Fatty Acids (SFA), Monounsaturated Fatty Acids (MUFA) and Polyunsaturated Fatty Acids (PUFA) content in
both types of Omani halwa. The SFA were present in highest concentration. The proportionate percentages
of SFA, MUFA and PUFA in white and black halwa were 64.57, 65.47, 31.28, 30.79, 4.11 and 3.74%,
respectively. The average GI and GL values for white and black halwa also did not vary (p<0.05) and were
54.8 and 52.0 and 14 and 13.4, respectively. Although the glycemic index values of Omani halwa fall in low
GI category (<55), it should be consumed with caution because of its high fat, in particular of SFA and high
sugar contents.
Key words: Omani halwa, proximate composition, fatty acids, glycemic index
INTRODUCTION
The people have passion for sweets globally and every
nation/culture has its own traditional sweet dishes that
are not only served on special ceremonies/occasions
but are also used as a gesture of hospitality in everyday
life. Omani halwa is one such example that is not only a
traditional sweet-dish from Oman but is also a favorite
in the Gulf region and in the Arab world. The history of
Omani halwa is well knitted in the social/cultural
structure of the local people and has become a key to
Omani hospitality when served with Omani coffee. Oman
lies in the South-Eastern part of Arabian Peninsula and
represents a fine mix of ancient society and modern
lifestyle. Drastic changes have occurred in the recent
past in the lifestyle and food consumption patterns of the
people as the people have shifted to consume more
energy-dense ready-made fast foods including the
sweets and savoury snack foods (Musaiger and Miladi,
1995; Ali et al., 2013). These changes have brought a
major shift in health related problems from the survival
issues to so-called nutrition related non-communicable
diseases of affluence such as obesity, diabetes,
hypertension and heart diseases. The results of the
National Health Survey have shown that the prevalence
of diabetes, impaired glucose tolerance, hypertension,
hypercholesterolemia and obesity is high in Oman
(Al-Riyami et al., 2000). The prevalence of these
conditions is higher in urban areas, in particular in older
people than the rural population (Al-Moosa et al., 2006).
The existence of metabolic syndrome in Oman has also
been reported to be comparable to developed countries
(Al-Lawati et al., 2003). In a recent study we reported that
obesity, high daily caloric intake, in particular higher
consumption of refined carbohydrates and protein were
associated with increased risk of Non-Hodgkin’s
Lymphoma (NHL) in Oman (Ali et al., 2013). It has been
suggested that chronic diseases will continue to drain
Oman’s human and financial resources, if appropriate
strategies are not developed and introduced to current
health care system (Al-Lawati et al., 2008).
The Omani halwa is a high energy-dense food that
consists mainly of fat, starch and sugar. Sweet dishes
containing high fat and high sugar are more palatable
and are therefore usually overeaten and may lead to
overweight and obesity (Rolls and Hammer, 1995). Only
limited information is available on the chemical
composition of commonly consumed traditional Omani
foods and mixed dishes, including Omani halwa
Pak. J. Nutr., 12 (8): 753-760, 2013
754
(Musaiger et al., 1998). Data on the nutrient composition granulated almonds and/or walnuts are added
of traditional foods is not only crucial to assess the dailyaccording to the type of halwa. At the end of cooking
dietary intakes of the local people but also for mealprocess, the surface is decorated with almonds and/or
planning to meet the nutrient requirements as well as inwalnuts. Some other ingredients may also be used
the prevention and control of various diet-relatedaccording to the good manufacturing practices as
diseases. The diet-analysis software which are mostlydescribed by the Ministry of Commerce and Industry in
available in the market to estimate the energy andOmani Standards for the Preparation of Halwa [Ministry
nutrient intake of individuals, lack the nutrient-of Commerce and Idustry (MCI), 2004].
composition data about the locally consumed traditionalThe proximate composition (moisture, ash, crude fiber,
foods. The databank on the nutrient composition ofcrude protein and total fat contents) of the representative
foods in these software’s is therefore required to besamples of Omani halwa was determined according to
updated with the actual nutrient-composition ofthe methods of Association of Official Analytical
traditional local foods. The modified diet-analysisChemists (AOAC, 2000). The Nitrogen Free Extract
software can then be used to estimate the nutrient(NFE) was calculated by difference (100 minus
requirements and develop meal plans including thepercentages of moisture, crude protein, total fat, ash and
traditional local foods for the local people. crude fibre). The values for the proximate analysis are
In our previous studies we reported about the chemicalexpressed as g per 100 g of halwa. The energy value
composition and glycemic index of different types of(kcal/100 g) of halwa was calculated by multiplying the
traditional Omani breads (Ali et al., 2010) and date fruits amount of carbohydrates, protein and fat contents in
(Ali et al., 2009) consumed in Oman. The Glycemic Index grams with 4, 4 and 9 respectively as described by Ali et
(GI) of foods is a numeric physiologic system ofal. (2009).
classifying the carbohydrate rich foods that ranks foods
on a scale from 0-100 based on their potential howDetermination of fatty acids composition: The fatty
quickly they are digested, absorbed and raise the bloodacids composition of halwa was determined using the
glucose level as compared to a standard food (Jenkinsgas chromatograph model “AGILENT 6890-N
et al., 1981; FAO/WHO, 1998). Consumption of low(Bellefonte, PA, USA). A fused capillary column attached
glycemic index foods has been shown to have long term with a flame ionization detector was used for the
beneficial effects on health (Jenkins et al., 2002;analysis of fatty acids. The column (SUPLECO SP-2380)
Brand-Miller et al., 2009; Chiu et al., 2011). Data on thewas 30 m long having an internal diameter of 0.25 mm
chemical composition and Glycemic Index (GI) values of and 0.20 µm of film thickness (SUPLECO Inc., Santa
local and traditional foods is therefore essential in dailyClara, CA, USA). The helium gas was used as carrier
meal planning and to make appropriate dietarygas. The standard operating conditions for the analysis
recommendations for the people. There is a paucity ofof fatty acids as given in the operating manual of the
information on the nutritional quality, chemicalequipment were followed. The extraction of the fatty
composition and glycemic index of various types ofacids as methyl esters was carried out as described by
Omani halwa. The present study was thereforethe methods of AOAC (2000). An Agilent 7683 series
conducted to determine the proximate composition, fatty injector was used to inject the extracts for fatty acids
acids content and glycemic index of two different typesanalysis which were identified by comparing their
(white and black) of Omani halwa. retention time with a commercially available standard
MATERIALS AND METHODS
Determination of chemical composition:
Representative samples of white and black Omani
halwa were collected from the local market in Muscat,
Oman. The Omani halwa is prepared conferring to the
centuries old traditional methods which are normally
passed on from one generation to another and are kept
as trade secret within the family. The main ingredients
of Omani halwa include butter oil, starch, sugar, water,
nuts, saffron, cardamom, rose water and sometimes
colours or flavours. The general process of preparation
is by adding sugar to the boiling water with continuous
stirring and then starch is added to it while the stirring
process continues until the mixture starts becoming
gelatinous. The butter oil (ghee) is then added and
stirring is continued until it turns into a thick jelly like
substance. At this stage rose water, saffron, cardamom,
mixture of 37 components of FAME Mix Standard
(SUPLECO Inc., Santa Clara, CA, USA). The
quantification of fatty acids was done by using
heneicosanoic acid (C21:0) methyl ester as an internal
standard and the results were calculated as g per 100 g
of halwa.
Determination of Glycemic Index (GI): The glycemic
index of Omani halwa was determined in normal healthy
human volunteers as described by Wolever et al. (1991)
and FAO/WHO (1998). The recommendations of
American Diabetic Association (ADA) were followed for
the inclusion criteria for volunteers. The volunteers had
the normal fasting blood glucose levels and did not
show any impairment in oral glucose tolerance test to
rule out the diabetes (ADA, 2006). Each volunteer was
required to read a written explanation of the study
protocol and signed an informed consent. The
Pak. J. Nutr., 12 (8): 753-760, 2013
755
volunteers were allowed to ask any question in order tofat (17.95%) and a little lower percentage of
have a clear idea about the experiment. Glucose wascarbohydrate (71.2%) in samples of Omani halwa and
used as a standard reference food. Ten normal healthyas a result higher energy value (446.5 kcal/100 g) as
human volunteers (undergraduate students from Sultancompared to our results. This may be due to the
Qaboos University, including both males and females)variability in ingredient composition used in the
were recruited for this study. The average age and Body preparation of various types of Omani halwa available in
Mass Index (BMI, kg/m ) of the volunteers were 22±0.9the local market. The main constituents in Omani halwa
2
years and 22.7±2.2, respectively. The mean body weight as indicated by proximate composition are carbohydrate
of the volunteers was 60.3±10.5 kg. The volunteers were and lipids. Rahman et al. (2012) reported that the
asked to report in the laboratory at 7:45 am after anpatterns of Texture Profile Analysis (TPA) attributes of
overnight fast of 12 hours for glycemic index testing. The Omani halwa were mostly linked to its moisture and fat
subjects were given the portions of test food andcontent. The moisture and sugar contents were
standard reference food (glucose) containing 50g ofsignificantly correlated with hardness whereas the
available carbohydrates in random order on separatemoisture and fat contents affected the firmness and
occasions with 250 mL of water. The glycemic indexchewiness characteristics of Omani halwa (Rahman et
testing protocol as described by Ali et al. (2009) wasal., 2012).
followed. A drop of capillary blood, obtained by finger
prick method, was used for measuring the bloodFatty acids composition of Omani halwa: Table 2 gives
glucose level. A SureStep Brand Professional Bloodthe fatty acid composition of white and black Omani
Glucose Meter (Johnson and Johnson Company,halwa. Some of the individual fatty acids in white and
USA) was used to measure the blood glucose level. The black halwa varied significantly (p<0.05). However, the
glycemic index was calculated using the incrementaloverall total amount of fatty acids observed in white and
area under the blood glucose response cure (IAUC) forblack halwa did not differ (p>0.05). Similarly the
the test food compared with the IAUC for the referenceproportionate percentage of Saturated Fatty Acids (SFA),
food taken by the same subject at 0 (fasting), 15, 30, 45, Monounsaturated Fatty Acids (MUFA) and
60, 90, 180 minutes after the ingestion of food. The GI = Polyunsaturated Fatty Acids (PUFA) in white and black
(IAUC of test food ÷ IAUC of standard food)*100 (Woleverhalwa also did not differ significantly (p>0.05). The
et al., 1991; FAO/WHO, 1998). highest concentration of fatty acids was SFA. The
Statistical analysis: The data obtained was analyzedhalwa were 64.57 and 65.47%, respectively. The main
statistically using descriptive statistics. The results areSFA found in white and black halwa were capric acid
expressed as means±standard deviation (SD). The(C10:0), lauric acid (C12:0), myristic acids (C14:0),
means were compared by using Student’s t-test aspalmitic acid (C16:0) and stearic acid (C18:0), whereas
described by Snedecor and Cochran (1989). Thethe main MUFA was oleic acid (C18:1). The
ethical approval of the study protocol was obtained fromproportionate percentages of MUFA in white and black
the Research in Ethics Committee of Sultan Qabooshalwa were found to be 31.28 and 30.79%, respectively.
University, Muscat, Oman. The PUFA were found in the lowest concentrations. The
RESULTS AND DISCUSSION
The proximate chemical composition of Omani halwa:
The proximate composition of Omani halwa is shown in
Table 1. No significant (p<0.05) differences were
observed in the proximate composition and energy
content of white and black Omani halwa. The values for
percentage moisture, crude protein, total fat, ash, crude
fiber and Nitrogen Free Extract (NFE) in white and black
halwa were 11.81 and 12.13, 0.28 and 0.44, 13.84 and
12.94, 0.68 and 0.57, 0.15 and 0.27, 73.24 and 73.65,
respectively. The energy values in white and black halwa
were 418.6 and 403.8 kcal/100 g respectively. Musaiger
et al. (1998) however reported higher percentages of
proportionate percentages of SFA in white and black
higher amounts of SFA present in the white and black
Omani halwa is considered to be due to its butter oil
(ghee) content that is used in its preparation. The butter
oil (ghee) mainly contains saturated fatty acids (Glew et
al., 1999; Dixit and Das, 2012). The specific types of fatty
acids in Omani halwa have been reported to be
significantly correlated with its all Texture Profile Analysis
(TPA) attributes (Rahman et al., 2012). Small amounts
of Trans-Fatty Acid (TFA) (Elaidic acid, C18:1-t and
Linolelaidic acid, C18:2-t) were also found to be present
in Omani halwa. Traces of TFA have been reported to
exist naturally in plant oils as well as in meat, milk and
dairy products (Ohnishi and Thompson, 1991; Kliem et
al., 2013). The presence of small quantities of TFA
Table 1: Proximate chemical composition (%) and energy value (kcal/ 100g) of Omani halwa
Type of food/ Crude Total Crude Energy
parameter Moisture protein fat Ash fibre NFE (kcal/100 g)
White halwa 11.81±0.9 0.28±0.1 13.84±1.1 0.68±0.1 0.15±0.1 73.24±1.5 418.6±8.9NS
Black halwa 12.13±0.7 0.44±0.1 12.94±0.9 0.57±0.1 0.27±0.1 73.65±1.9 403.8±10.3NS
NS: non-significant
Pak. J. Nutr., 12 (8): 753-760, 2013
756
Table 2: The average fatty acids composition of White and Black Halwa (g/100 g of halwa)
Mean±SD
--------------------------------------------------------------------------------------------------
Fatty acid White halwa Black halwa
C4:0 (Butyric) 0.098±0.034 0.069±0.029
C6:0 (Caproic) 0.154±0.057 0.130±0.005
C8:0 (Caprylic) 0.114±0.045 0.109±0.049
C10:0 (Capric) 0.334±0.099 0.450±0.085
C11:0 (Undecanoic) 0.065±0.002 0.035±0.004
C12:0 (Lauric) 0.514±0.090 0.739±0.065
C13:0 (Tridecanoic) 0.011±0.004 0.017±0.004
C14:0 (Myristic) 1.438±0.057 1.742±0.218
C14:1 (Myristoleic) 0.095±0.060 0.049±0.015
C15:0 (Pentdecanoic) 0.192±0.051 0.267±0.040
C15:1 (Cis-10-pentadecanoic) 0.131±0.073 0.158±0.069
C16:0 (Palmitic) 1.369±0.066 1.281±0.104
C16:1 (Palmitoleic) 0.352±0.059 0.242±0.025
C17:0 (heptadecanoic) 0.089±0.015 0.103±0.101
C17:1 (Cis-10-Heptadecanoic) 0.086±0.056 0.188±0.029
C18:0 (Stearic) 1.189±0.165 0.983±0.111
C18:1 (Oleic) 1.848±0.269 1.961±0.329
C18:1 (Elaidic) trans-fat 0.031±0.009 0.036±0.006
C18:2 (Linoleic) 0.093±0.044 0.075±0.010
C18:2 (Linolelaidic) trans fat 0.019±0.001 0.017±0.001
C18:3 ((-linolenic) 0.011±0.005 0.004±0.001
C18:3 ("-linolenic) 0.126±0.043 0.158±0.035
C20:0 (Arachidic) 0.173±0.022 0.219±0.026
C20:2 (Cis-11, 14-Ecosadienoic) 0.009±0.002 0.010±0.002
C20:3)Cis-11, 14, 17 Eicosatrienoic) 0.013±0.005 0.015±0.006
C20:4 (Arachidonic) 0.008±0.001 0.008±0.001
C20:5 (Cis-5, 8, 11, 14, 17-Eicosapentaenoic) 0.011±0.005 0.013±0.005
C21:0 (Henicosanoic) 0.079±0.093 0.152±0.049
C22:0 (behenic) 0.014±0.004 0.017±0.001
C22:6 (Cis-4, 7, 10, 13, 16, 19-Docosahexaenoic) 0.002±0.001 0.003±0.001
C23:0 (Tricosanoic) 0.005±0.002 0.006±0.001
C24:0 (Lignoceric) 0.010±0.004 0.013±0.006
C24:1 (Nervonic) 0.005±0.002 0.003±0.002
Total Fatty acids 9.054±0.443 9.667±1.059
NS NS
Total Saturated fatty acids (SFA) 5.847±0.318 (64.57%)* 6.329±0.379 (65.47%)*
NS NS
Total Monounsaturated fatty acids (MUFA) 2.832±0.169 (31.28%)* 2.976±0.181 (30.79%)
NS NS
Total Polyunsaturated fatty acids (PUFA) 0.372±0.089 (4.11%)* 0.362±0.085 (3.74%)*
NS NS
* = Proportionate %age of SFA, MUFA and PUFA of the total fatty acids
NS = non-significant
in Omani halwa (<0.5 g/100g of lipids) may be due intake had little effect on serum cholesterol and glycated
to its ingredient composition as well as to thehemoglobin (HbA1c) levels in healthy young Japanese
preparation process, as one of the major ingredients iswomen.
the butter oil. This amount is however much less than
the permissible standard limits for TFA in food products. Glycemic index of omani halwa: On the average the
Almar et al. (2013) reported that the TFA content in most volunteers had normal fasting blood glucose values
of the tested Malaysian foods such as bakery products,(96±2 mg/dL) and also did not show any impaired
snacks, dairy products, fast foods and breakfast cerealsfasting blood glucose (IFG) responses. The glycemic
was <1 g/100 g of lipids. Saturated fats and trans-fatsresponses of the volunteers for the standard reference
have been shown to be associated with higher risk offood (glucose) and Omani halwa are shown in Fig. 1.
coronary heart diseases and therefore their dietaryThe pattern of glycemic responses for both types of
intake should be restricted within the recommendedOmani halwa was very much similar. The ingestion of
limits (WHO, 2003; Muzaffarian et al., 2009; Mashal et al., halwa didn’t drastically increase the glycemic response.
2012). It has been recommended that dietary intake ofThe results for Glycemic Index (GI) and Glycemic Load
TFA should be less than 1% of daily total energy intake(GL) values of white and black halwa are presented in
(WHO, 2003). Takeuchi et al. (2013) showed thatTable 3. Although the white halwa showed a little higher
consuming TFA at less than 1% of total daily energyglycemic index value (54.8±15.3) as compared to black
Pak. J. Nutr., 12 (8): 753-760, 2013
757
Fig. 1: The average glycemic response of volunteers on
standard reference food (glucose) and test food
(Omani halwa)
Table 3: The average glycemic index of white and black Omani
halwa Mean±SD
------------------------------------------------
Type of food/parameter GI GL*
White halwa 54.8±15.3 14.0±1.3
NS NS
Black halwa 52.0±16.5 13.4±1.5
NS NS
GI: Glycemic Index, GL: Glycemic Load. *The serving size of
halwa is assumed to be as 35 g. The available carbohydrate
(CHO) in one serving of white and black Omani halwa is
calculated to be 25.6 and 25.8 g, respectively. GL = (GI x
available CHO per serving)/100
halwa (52.0±16.5), the difference was not statistically
significant (p<0.05). The glycemic index values for both
types of Omani halwa fall in the low glycemic index
category (<55.0) of foods (Foster-Powell et al., 2002;
Brand-Miller et al., 2003). The similar low GI values for
both types of Omani halwa could be due to a number of
factors mainly because the same type of ingredients and
similar processing method is used in the preparation of
both types of halwa. The only difference is the type of
sugar used which is of red colour in case of black halwa
and white in case of white halwa. However, the reason
for the low GI values of these Omani halwa cannot be
exactly explained. A number of variables including both
the food and physiologic factors may influence the
absolute amount of postprandial blood glucose after the
digestion and absorption of nutrients from the foods (Pi-
Suneyer, 2002; Brouns et al., 2005; Aziz, 2009). The
physical form of the food molecules, nature of
monosaccharide and starch, the way of cooking and
degree of processing, as well as the amount and type of
other food components present can influence the GI
values of foods (Monge et al., 1990; Brouns et al., 2005;
Parada and Aguilera, 2011). The lower GI values of
Omani halwa tested in this study may be attributed to the
way it is processed with a lot of butter oil, sugar and
starch. The preparation process may result in the
production of more compact starch granules which give
it the gelatinous structure that might result in slow
release of glucose after digestion. The food products
containing similar amounts of starch can have different
postprandial blood glucose responses which may be
due to the composition and structure of food as well as
due to the simultaneous ingestion of other food
components (Parada and Aguilera, 2011). The high fat
content of halwa might also have played a role in
delaying the gastric emptying time which may also have
tended to flatten the glycemic response curve (Collier et
al., 1983; Gannon et al., 1993; Foster-Powell et al.,
2002).
The GL values for white and black halwa (14.0±1.3 and
13.4±1.5, respectively) also didn’t vary significantly
(p<0.05). The glycemic load of a food is defined as a
function of the amount of carbohydrate intake per serving
and the glycemic index of that food. One unit of GL
approximate the glycemic effect of 1 gram of glucose.
The serving size of Omani halwa is assumed to be 35 g
that contained 25.6 and 25.8 g of available carbohydrate
in one serving respectively. The GL values for white and
black halwa fall within the medium glycemic load
category (Foster-Powell et al., 2002; Brand-Miller et al.,
2003). Data from various epidemiological and
interventional studies has revealed that lower GI foods
and GL diets may have positive effects on the appetite
and food intake and can help to improve the glycemic
control without compromising hypoglycemic events. Low
GI foods have shown many beneficial effects in
controlling a wide range of pathophysiological
conditions such as diabetes, cardiovascular disease,
obesity and certain forms of cancer (Alfenas and Mattes,
2005; Barclay et al., 2008; Chiu et al., 2011; Fleming and
Godwin, 2013; Rouhani et al., 2013; Schwingshackl and
Hoffmann, 2013). The results from some other
randomized controlled trials however suggest that low GI
and GL diets have inconsistent effects on CVD risk
factors (Kristo et al., 2013). More studies are therefore
required to further elucidate and interpret the results.
The excessive consumption of energy-dense foods
containing added sugar and lipids is considered as the
leading cause of obesity and cardiovascular diseases
worldwide. Higher consumption of such foods may not
only lead to some essential nutrient deficiencies but has
also been associated with many metabolic
abnormalities and poor health conditions (Johnson et
al., 2009; Britton et al., 2012). The updated US
Department of Agriculture (USDA) Food Patterns after
considering the 2010-US Dietary Guidelines for
Americans have identified more healthful foods choices
and recommend that the people should meet their daily
nutrient needs by consuming a variety of nutrient-dense
foods. By consuming nutrient-dense foods, the people
can meet their daily nutrient requirements within their
daily energy allowance and can have limited amounts of
Pak. J. Nutr., 12 (8): 753-760, 2013
758
foods containing solid fats and added sugars (8-19% of
calories) in their daily meal plan (Britton et al., 2012).
Although the Omani halwa showed low GI values, it is an
energy-dense food that contains high amounts of butter
oil and added sugars. Therefore only small quantities
should be consumed within the recommended daily
dietary energy intake level as a part of a varied diet
containing other nutrient-dense foods. Majority of the
people do not show dietary self-efficacy and self-
management behaviours in their diabetes control and
do not meet the recommended goals for diabetes care
(Al-Khawaldeh et al., 2012; Ali et al., 2013). It is therefore
important to develop appropriate educational strategies
and awareness campaigns to educate the people in
promoting the self-management behaviours for making
healthy food choices to control their dietary intake and
lifestyle behaviours in the prevention of non-
communicable diseases.
Conclusion: Omani halwa is an important traditional
food that is served in Omani homes together with
Arabian coffee as a part of culture. It is served both at
times of joy and sorrow, on religious occasions and on
festivals as a symbol of hospitality. The main
components in Omani halwa are butter oil (ghee), sugar
and starch that make it a highly energy-dense food. The
proximate chemical composition, fatty acids contents,
energy value, glycemic index and glycemic load in both
types (white and black) of Omani halwa did not differ
significantly. The average glycemic index values of white
and black halwa (52.0 and 54.8, respectively) fall within
low glycemic index category whereas the glycemic load
values (14.0 and 13.4, respectively) fall in the medium
category. We are reporting for the first time about the GI
and GL values for Omani halwa. Although GI values of
Omani halwa were found to be low, it is suggested that
keeping in view its high energy-density and higher
concentration of SFA, only small quantities should be
consumed within the recommended daily dietary energy
intake allowance as a part of a varied diet. Such data is
of primary significance in developing the appropriate
dietary management strategies in daily meal planning to
reduce the risk of chronic diseases.
ACKNOWLEDGEMENT
We thank the volunteers for their cooperation and help.
We also thank Ms. Buthaina Saleh Al-Bulushi for her
technical assistance. The financial support provided by
Sultan Qaboos University under SQU internal research
grants (IG/AGR/FOOD/04/01 and IG/AGR/FOOD/11/01) is
greatly acknowledged. We also thank Prof. Thomas
Wolever of University of Toronto, Canada, for providing
us the software to calculate the IAUC and GI values of
foods.
REFERENCES
Alfenas, C.G. and R.D. Mattes, 2005. Influence of
glycemic index/load on glycemic response, appetite
and food intake in healthy humans. Diabetes Care,
28: 2123-2129.
Ali, M.K., K.M. Bullard, J.B. Saaddine, C.C. Cowie, G.
Imperatore and E.W. Gregg, 2013. Achievement of
goals in U.S. diabetes care, 1999-2010. N. Engl. J.
Med., 368: 1613-1624.
Ali, A., B.S. Al-Belushi, M.I. Waly, M. Al-Moundhari and I.A.
Burney, 2013. Dietary and lifestyle factors and risk
of non-Hodgkin’s lymphoma in Oman. Asian Pac. J.
Cancer Prev., 14: 841-848.
Ali, A., Y.M. Al-Kindi and F. Al-Said, 2009. Chemical
composition and glycemic index of 3 varieties of
Omani dates. Int. J. Food Sci. Nutr., 60: 51-62.
Ali, A., H.A.S. Al-Nassri, B. Al-Rasasi, M.S. Akhtar and
B.S. Al-Belushi, 2010. Nutritional quality and
glycemic index of traditional Omani breads. Int. J.
Food Prop., 13: 213-223.
Al-Khawaldeh, O.A., M.A. Al-Hassam and E.S. Froelicher,
2012. Self-efficacy, self-management and glycemic
control in adults with type 2 diabetes mellitus. J.
Diabetes Complications, 26: 10-16.
Al-Lawati, J.A., A.J. Mohammad, H.Q. Al-Hinai and P.
Jousilathi, 2003. Prevalence of the metabolic
syndrome among Omani adults. Diabetes Care, 26:
1781-1785.
Al-Lawati, J.A., R. Marby and A.J. Mohammad, 2008.
Addressing the threat of chronic diseases in Oman.
Publ. Health Res. Pract. Policy, 5: 1-7.
Al-Moosa, S., S. Allin, N. Jemiai, J.A. Al-Lawati and E.
Mossialos, 2006. Diabetes and Urbanization in the
Omani population: an analysis of the national
survey data. Popul. Health Metrics, 4: 5.
Al-Riyami, A., M. Afifi, H. Al-Kharusi and M. Morsi
(Editors), 2000. National Health Survey-2000. Vol 1.
Study of lifestyle risk factors. Directorate of
Research and Studies, Ministry of Health, Muscat,
Sultanate of Oman.
Almar, A.D., M.E. Norhaizan, R. Azimah, A. Azrina and
Y.M. Chan, 2013. The tran-fatty acids content of
selected foods in Malaysia. Malaysian J. Nutr., 19:
87-98.
American Diabetes Association (ADA), 2006. Diagnosis
and classification of diabetes mellitus. Diabetes
Care, 29: S43-S48.
Association of Official Analytical Chemists (AOAC), 2000.
Official Methods of Analysis. 17th Edn., Williams
Howitz. Washington, USA.
Aziz, A., 2009. The glycemic index: methodological
aspects related to the interpretation of health effects
and to regulatory labeling. JAOAC Int., 92: 879-887.
Barclay, A.W., P. Petocz, V.M. Flood, T. Prvan, P. Mitchell
and J.C. Brand-Miller, 2008. Glycemic index,
glycemic load and chronic diseases risk a meta-
analysis of observational studies. Am. J. Clin. Nutr.,
87: 627-637.
Pak. J. Nutr., 12 (8): 753-760, 2013
759
Brand-Miller, J.C., S. Hayne, P. Petocz and S. Colgiuri,Johnson, R.K., L.J. Apple, M. Brands, B.V. Howard, M.
2003. Low glycemic Index diets in the management
of diabetes. A meta-analysis of randomized
controlled trials. Diabetes Care, 26: 2261-2267.
Brand-Miller, J.C., J. Mc-Millan-Price, K. Steinbeck and I.
Caterson, 2009. Dietary glycemic index: health
implications. J. Am. Coll. Nutr., 28: 446S-449S.
Britton, P., L.E. Cleveland, K.L. Koegel, K.J. Kuczynski
and S.M. Nickols-Richardson, 2012. Updated US
Department of Agriculture Food Patterns meet goals
of the 2010 dietary guidelines. J. Acad. Nutr. Diet,
112: 1648-1655.
Brouns, F., I. Bjorck, K. Frayn, A. Gibbs, V. Lang, G.
Slama and T.M. Wolever, 2005. Glycaemic index
methodology. Nutr. Res. Rev., 18: 145-171.
Chiu, C.J., S. Liu, W.C. Willet, T.M.S. Wolever, J.C. Brand-
Miller, A.W. Barclay and A. Taylor, 2011. Informing
food choices and health outcomes by use of dietary
glycemic index. Nutr. Rev., 69: 231-242.
Collier, G. and K. O’Dea, 1983. The effect of coingestion
of fat on the glucose, insulin and gastric inhibitory
peptide responses to carbohydrate and protein. Am.
J. Clin. Nutr., 37: 941-944.
Dixit, S. and M. Das, 2012. Fatty acids composition
including trans-fatty acids in edible oils and fats:
probable intake in Indian population. J. Food Sci.,
77: T188-T199.
FAO/WHO, 1998. Carbohydrates in human nutrition:
Report of a joint FAO/WHO Expert consultation
Rome, 14-18 April, 1997. FAO-Food and Nutrition
Paper No. 66, FAO, Rome, Italy.
Fleming, P. and M. Godwin, 2013. Low-glycaemic index
diets in the management of blood lipids: a
systematic review and meta-analysis. Family
Practice Jun 26, Epub ahead of print.
Foster-Powell, K., S. Holt and J.C. Brand-Miller, 2002.
International table of glycemic index and glycemic
load values. Am. J. Clin. Nutr., 76: 5-56.
Gannon, M.C., N. Ercan, S.A. Westphal and F.Q. Nuttall,
1993. Effect of added fat on plasma glucose and
insulin response to ingested potato in individuals
with NIDDM. Diabetes Care, 16: 874-880.
Glew, R.H., S.N. Okolo, L.T. Chuang, Y.S. Huang and
D.J. VanderJagt, 1999. Fatty acid composition of
Fulani “butter oil” made from cow’s milk. J. Food
Compos. Anal., 12: 235-240.
Jenkins, D., C. Kendall and L. Augustin, 2002. Glycemic
index: overview of implications in health and
disease. Am. J. Clin. Nutr., 76: 266S-273S.
Jenkins, D., T.M.S. Wolever, R. Taylor, H. Barker, H.
Fielden, J. Baldwin, A. Bowling, H. Newman, A.
Jenkins and D. Goff, 1981. Glycemic index of Foods:
a physiological basis for carbohydrate exchange.
Am. J. Clin. Nutr., 34: 362-366.
Levefrve, R.H. Lusting, F. Sacks, L.M. Steffen, J.
Wylie-Rosset and AHA Nutrition Committee, 2009.
Dietary sugars intake and cardiovascular health: a
scientific statement. from the American Heart
Association. Circulation, 120: 1011-1020.
Kliem, K.E., K.J. Shingfield, K.M. Livingstone and D.I.
Givens, 2013. Seasonal variation in the fatty acid
composition of milk available at retail in the United
Kingdom and implications for dietary intake. Food
Chem., 141: 274-281.
Kristo, A.S., N.R. Matthan and A.H. Lichtenstein, 2013.
Effect of diets differing in glycemic index and
glycemic load on cardiovascular risk factors: review
of randomized controlled-feeding trials. Nutrients, 5:
1071-1080.
Mashal, R.H., A. Oudeh, K.M. Al-Ismail, K.A. Abu-
Hammour and H.A. Al-Domi, 2012. Association of
dietary intake of trans-fatty acids and coronary heart
disease risk in Jordanian subjects. Pak. J. Nutr., 11:
423-433.
MCI, Ministry of Commerce and Industry, 2004. Omani
Halwa, Omani Standard No. (1635), Directorate
General for Specifications and Measurements, P.O.
Box 550, Muscat, Sultanate of Oman.
Monge, L., G. Cortassa, G. Mussino and Q. Carta, 1990.
Glycoinsulinaemic response, digestion and
intestinal absorption of starch contained in two
types of spaghetti. Diabetes Nutr. Metab., 3: 239-
246.
Musaiger, A.O., 1998. Chemical composition of some
traditional dishes of Oman. Food Chem., 61: 17-22.
Musaiger, A.O. and M. Miladi, 1995. Food consumption
patterns and dietary habits in the Arab Gulf
countries. Report of the FAO/RNE, UAE University,
Al-Ain UAE, Pages: 134.
Muzaffarian, D., A. Aro and W.C. Willet, 2009. Health
effects of trans fatty acids: experimental and
observational evidence. Eur. J. Clin. Nutr., 63: S5-
S21.
Ohnishi, M. and G.A. Jr. Thompson, 1991. Biosynthesis
of the unique trans )hexadecanoic acid
3
component of chloroplast phosphatidyl glycerol:
evidence concerning its site and mechanism of
formation. Arch. Biochem. Biophys., 288: 591-599.
Parada, J. and J.M. Aguilera, 2011. Review: Starch
matrices and the glycemic response. Food Sci.
Technol. Int., 17: 187-204.
Pi-Suneyer, F.X., 2002. Glycemic index and disease. Am.
J. Clin. Nutr., 76: 290S-298S.
Rahman, M.S., Q. Al-Shamsi, A. Abdullah, M.
Claereboudt, B. Al-Belushi, R. Al-Maqbaley and J. Al-
Sabahi, 2012. Classification of commercial Omani
halwa by physico-chemical properties and
instrumental texture profile analysis (TPA). Ital J.
Food Sci., 24: 2012-2012.
Pak. J. Nutr., 12 (8): 753-760, 2013
760
Rolls, B.J. and V.A. Hammer, 1995. Fat, carbohydrateTakeuchi, H., T. Kusuwada, Y. Shirokawa, S. Harada and
and regulation of energy intake. Am. J. Clin. Nutr.,
51: 72-75.
Rouhani, M.H., A. Saleh-Abargouei and L. Azadbakht,
2013. Effect of glycemic index and glycemic load on
energy intake in children. Nutrition, June 6, 2013
(Epub ahead of print).
Schwingshackl, L. and G. Hoffmann, 2013. Long-term
effects of low glycemic index/load vs. high glycemic
index/load diets on parameters of obesity and
obesity-associated risks: A systematic review and
meta-analysis. Nutrition Metabolism and
Cardiovascular Diseases, June 17, 2013 (Epub
ahead of print).
Snedecor, G. and G. Cochran, 1989, Statistical Methods,
8th Edn., Iowa State University Press. IOWA, USA.
M. Sugano, 2013. Supplementation with 1% energy
trans Fatty acids had little effect on serum
cholesterol levels in healthy young Japanese
women. Biosci. Biotechnol. Biochem., 77: 1219-
1222.
WHO, 2003. Diet, nutrition and prevention of chronic
diseases. Report of a Joint WHO/FAO Expert
Consultation, WHO Technical Report Series No.
916, WHO, Geneva, Switzerland.
Wolever, T.M.S, D.J.A. Jenkins, A.L. Jenkins and R.G.
Josse, 1991. The glycemic index methodology and
clinical implications. Am. J. Clin. Nutr., 54: 846-854.
... types of Omani halwa were found to be within the They were randomly divided into 7 groups containing 6 low GI category (<55), its total fat and carbohydrate rats in each group. The rats were kept in individual contents were found to be about 14 and 73%, cages with wire-meshed floors equipped with feeders to respectively (Ali et al., 2013b). ...
... Representative samples of two different types of Omani halwa (white and black) were collected from the local market. The details about the preparation process and chemical composition of Omani halwa were given in our previous paper (Ali et al., 2013b ...
Article
Full-text available
Omani halwa is a traditional sweet delicacy. The present study evaluated the effects of feeding different levels of Omani halwa on the growth performance, fasting plasma glucose, glycated hemoglobin (HbA1c) and plasma lipid profile of Sprague-Dawley rats. Forty two, 4 weeks old male SD-rats were randomly divided into 7 groups containing 6 rats in each. Six experimental diets, (in which the normal rat chow was replaced with either white or black Omani halwa at 10, 15 and 20% level), were prepared and fed for 10 weeks. The group fed on rat chow acted as control. No significant (p<0.05) differences were observed in the feed consumption and growth performance of rats fed diets containing different levels and types of halwa. Significant (p<0.05) differences were observed in fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) values in rats fed different experimental diets. Diets containing 20% of halwa showed significantly (p<0.05) higher FPG and HbA1c values. Similarly the rats fed diets containing 20% of halwa showed significantly (p<0.05) higher lipid profile i.e., TC, TG, HDL-C and LDL-C values as compared to control. However, the TC/HDL-C ratio did not differ significantly (p>0.05). The plasma creatinine levels differed significantly (p<0.05) whereas the plasma albumin levels did not differ (p>0.05) in rats fed various experimental diets. Feeding Omani halwa at 15% level in diets did not affect (p>0.05) the growth, fasting plasma glucose, glycated hemoglobin (HbA1c) and lipid profile of rats.
... types of Omani halwa were found to be within the They were randomly divided into 7 groups containing 6 low GI category (<55), its total fat and carbohydrate rats in each group. The rats were kept in individual contents were found to be about 14 and 73%, cages with wire-meshed floors equipped with feeders to respectively (Ali et al., 2013b). ...
... Representative samples of two different types of Omani halwa (white and black) were collected from the local market. The details about the preparation process and chemical composition of Omani halwa were given in our previous paper (Ali et al., 2013b ...
Article
Omani halwa is a traditional sweet delicacy. The present study evaluated the effects of feeding different levels of Omani halwa on the growth performance, fasting plasma glucose, glycated hemoglobin (HbA1c) and plasma lipid profile of Sprague-Dawley rats. Forty two, 4 weeks old male SD-rats were randomly divided into 7 groups containing 6 rats in each. Six experimental diets, (in which the normal rat chow was replaced with either white or black Omani halwa at 10, 15 and 20% level), were prepared and fed for 10 weeks. The group fed on rat chow acted as control. No significant (p<0.05) differences were observed in the feed consumption and growth performance of rats fed diets containing different levels and types of halwa. Significant (p<0.05) differences were observed in fasting plasma glucose (FPG) and glycated hemoglobin (HbA1c) values in rats fed different experimental diets. Diets containing 20% of halwa showed significantly (p<0.05) higher FPG and HbA1c values. Similarly the rats fed diets containing 20% of halwa showed significantly (p<0.05) higher lipid profile i.e., TC, TG, HDL-C and LDL-C values as compared to control. However, the TC/HDL-C ratio did not differ significantly (p>0.05). The plasma creatinine levels differed significantly (p<0.05) whereas the plasma albumin levels did not differ (p>0.05) in rats fed various experimental diets. Feeding Omani halwa at 15% level in diets did not affect (p>0.05) the growth, fasting plasma glucose, glycated hemoglobin (HbA1c) and lipid profile of rats.
... types of Omani halwa were found to be within the They were randomly divided into 7 groups containing 6 low GI category (<55), its total fat and carbohydrate rats in each group. The rats were kept in individual contents were found to be about 14 and 73%, cages with wire-meshed floors equipped with feeders to respectively (Ali et al., 2013b). ...
... Representative samples of two different types of Omani halwa (white and black) were collected from the local market. The details about the preparation process and chemical composition of Omani halwa were given in our previous paper (Ali et al., 2013b ...
... The frequencies of food items were transformed into intake on daily basis to calculate the macronutrient intake in grams. Food intake assessment data was based on the nutrient analysis program or previously determined food composition of traditional local Omani dishes [19][20][21][22]. ...
Article
Full-text available
In a cross-sectional study, we determined the dietary patterns and nutritional status of Omani school students (12-15 years), and their association with student’s academic performance. A study questionnaire, including a semiquantitative food frequency questionnaire, was used to collect data. Results indicated that 36% of Omani school students regularly consumed breakfast, whereas only 21.7% had daily 3 meals. Similarly, 30.5% of students consumed fruits ≥ 2 serving/day, 26.6% consumed vegetables ≥ 3 serving/day, and 49.8% consumed fish ≥ 2 serving/week. Significant differences were observed regarding breakfast consumption among genders, regular intake of daily 3 meals, fruits, fish, avoiding soft drinks, nutritional knowledge, total energy and macronutrient intake. Based on BMI, 12.3 % of students were overweight, and 26.1% were obese. The students did not have enough nutritional knowledge and showed unhealthy dietary patterns indicated by their mediocre Omani Diet Scores. Daily energy and macronutrient intakes in males were significantly higher than females. Only fish intake, avoiding soft drinks, waist to height ratio (WHtR), and nutritional knowledge score showed significant associations with student’s academic performance. Healthy dietary patterns and improved nutritional status of school students showed a positive association with their academic performance, suggesting that more focus should be placed in developing healthy dietary patterns.
... The frequencies of food items were transformed into intake on daily basis to calculate the macronutrient intake in grams. Food intake assessment data was based on the nutrient analysis program or previously determined food composition of traditional local Omani dishes [19][20][21][22]. ...
... The frequencies of food items were transformed into intake on daily basis to calculate the macronutrient intake in grams. Food intake assessment data was based on the nutrient analysis program or previously determined food composition of traditional local Omani dishes [19][20][21][22]. ...
Article
Full-text available
The Glycemic Load (GL) of a food or mixed meal is defined as the amount of carbohydrates in grams contained in each serving of food or meal multiplied by its Glycemic Index (GI) and divided by 100. The dietary GL score for an entire day is calculated as the sum of the GL for all the individual food servings consumed. The present study was conducted to compare the changes in dietary patterns and to correlate the daily dietary GL intake and physical activity level in female university students with their weight gain/loss status over a period of 6 months. Two hundred healthy female university students (18-25 years of age) living in hostels at Sultan Qaboos University campus were randomly recruited for this study. The dietary food intake data was collected at two occasions (day 1 and after 6 months) using a semi-quantitative food frequency questionnaire in personal interviews. Anthropometric measurements including weight, height, Body Mass Index (BMI), waist and hip circumferences and waist to hip ratio as well as the physical activity level were evaluated. 1The results showed that the dietary intake patterns of students changed from their usual home eating patterns while residing at the university campus. The subjects consumed low glycemic load diets, showed a slight reduction in body weight and maintained a normal BMI with a score of waist/hip ratio < 1, with no significant differences in the time spent for physical activity as well as the physical activity factor as determined by TANITA. The volunteers were consuming low GL-diets that appear to be a major determinant of their weight status independent of physical activity level.
Article
Full-text available
Introduction: The overall health status of the Omani population has evolved over the past 4 decades from one dominated by infectious disease to one in which chronic disease poses the main challenge. Along with a marked reduction in the incidence of infectious diseases, improvements in health care and socioeconomic status have resulted in sharp declines in infant and early childhood mortality and dramatic increases in life expectancy. Methods: Focusing on the time period from 1990 through 2005, we reviewed relevant epidemiological studies and reports and examined socioeconomic indicators to assess the impact of the changing disease profile on Oman's economy and its health care infrastructure. Results: Over the next 25 years, the elderly population of Oman will increase 6-fold, and the urbanization rate is expected to reach 86%. Currently, more than 75% of the disease burden in Oman is attributable to noncommunicable diseases, with cardiovascular disease as the leading cause of death. The distribution of chronic diseases and related risk factors among the general population is similar to that of industrialized nations: 12% of the population has diabetes, 30% is overweight, 20% is obese, 41% has high cholesterol, and 21% has the metabolic syndrome. Conclusion: Unless reforms are introduced to the current health care system, chronic diseases will constitute a major drain on Oman's human and financial resources, threatening the advances in health and longevity achieved over the past 4 decades.
Article
Full-text available
There is a lack of information on the trans fatty acid (TFA) content in Malaysian foods. The objective of this study is to determine the TFA content of bakery products, snacks, dairy products, fast foods, cooking oils and semisolid fats, and breakfast cereals and Malaysian fast foods. This study also estimated the quantity of each isomer in the foods assayed. The trans fatty acid content of each food sample was assessed in duplicate by separating the fatty acid methyl esters (FAME) in a gas chromatography system equipped with HP-88 column (USA: split ratio 10: 1) for cis/trans separation. Five major TFA isomers, palmitoelaidic acid (16: 1t9), petroselaidic acid (18:1t6), elaidic acid (18:1t9), vaccenic acid (18: 1t11) and linoelaidic acid (18:2t9, 12), were measured using gas chromatography (GC) and the data were expressed in unit values of g/100 g lipid or g/100 g food. The total TFA contents in the studied foods were < 0.001 g-8.77 g/100 g lipid or < 0.001 g-5.79 g/100 g foods. This value falls within the standard and international recommendation level for TFA. The measured range of specific TFA isomers were as follows: palmitoelaidic acid (< 0.001 g-0.26 g/100 g lipid), petroselaidic acid (< 0.001 g - 3.09 g/100 g lipid), elaidic acid (< 0.001 g-0.87 g/100 g lipid), vaccenic acid (< 0.001 g-0.41 g/100 g lipid) and linoelaidic acid (< 0.001 g-6.60 g/100 g lipid). These data indicate that most of the tested foods have low TFA contents (< 1 g/100 g lipid).
Article
Full-text available
Dietary glycaemic index (GI) is a measure of the postprandial glycaemic response to carbohydrates. Observational studies have found increased triglycerides and decreased high-density lipoprotein levels in patients consuming higher GI foods. Our aim was to review and synthesize the evidence on the effect of low-glucose index diets on serum lipid levels. We conducted a systematic review and meta-analysis of randomized controlled trials on the effect of low-GI diets on serum lipid levels. We searched PubMed, Embase and Cochrane Library for published, English-language, randomized controlled trials comparing low-GI and high-GI diets for the management of blood lipids in the general population with at least 4 weeks of follow-up. We conducted a meta-analysis assuming a random effects model. Four studies met the criteria for inclusion in the systematic review and meta-analysis. The individual studies did not always show a significant effect of a low-GI diet on serum lipids; however, when combined in a meta-analysis, low-GI diets were shown to have a significant effect on decreasing total cholesterol and low-density lipoprotein (LDL) cholesterol over a short time span (5-12 weeks). There was no significant effect on high-density lipoprotein or triglyceride levels. The forest plots for total cholesterol and LDL cholesterol did not show significant statistical heterogeneity (I (2) = 0%). This meta-analysis suggests that a low-GI diet may help lower total and LDL cholesterol. The generalizability of these findings is likely limited by heterogeneity in individual study definitions of low- or high-GI diets.
Article
Full-text available
Background: The incidence of various types of cancers including the non-Hodgkin's lymphoma (NHL) has increased during the recent years. Diet and lifestyle factors have been reported to play an important role in the etiology of NHL. However, no such data are available from the Middle Eastern countries, including Oman. Materials and methods: Forty-three histologically confirmed cases of non-Hodgkin's lymphoma (NHL) diagnosed at the Sultan Qaboos University Hospital (SQUH) and the Royal Hospital (RH), Muscat, Oman and forty-three age and gender matched controls were the subjects of this study. Frequency matching was used to select the control population. Information on social and demographic data as well as the dietary intake was collected by personal interviews, using a 117-items semi-quantitative food frequency questionnaire. Results: A non-significant increased risk of NHL was observed with higher body mass index (BMI) (OR=1.20, 95%CI: 0.45, 2.93), whereas a significantly decreased risk of NHL was associated with a higher educational level (OR=0.12, 95%CI: 0.03, 0.53). A significantly increased risk was observed for higher intake of energy (OR=2.67, 95%CI: 0.94, 7.57), protein (OR=1.49, 95%CI: 0.54, 4.10) and carbohydrates (OR=5.32, 95%CI: 1.78, 15.86). Higher consumption of daily servings from cereals (OR=3.25, 95%CI: 0.87, 12.09) and meat groups (OR=1.55, 95%CI: 0.58, 4.15) were also found to be associated with risk of NHL, whereas a significantly reduced risk was associated with higher consumption of vegetables (OR=0.24, 95%CI: 0.07, 0.82). The consumption of fruits, milk and dairy products however showed no significant association with the risk of developing NHL. Conclusion: The results suggest that obesity, high caloric intake, higher consumption of carbohydrate and protein are associated with increased risk of NHL, whereas a significantly reduced risk was observed with higher intake of vegetables.
Article
Pasta (e.g. spaghetti) is one of the commonly used starchy foods that causes relatively moderate blood glucose variations and is thus recommended for diabetic subjects. In an investigation of the moderate glycaemic index of pasta, two test meals composed of durum-wheat spaghetti (A) and soft-wheat spaghetti (B) (75 g carbohydrate equivalent) were given to 15 healthy subjects. The two products were physically identical. Differences in their gluten characteristics were determined by means of a rheologic study. The glycoinsulinaemic response, as expressed by the incremental areas under the curve, appears to be similar for the two products. Their moderate glycaemic index (A = 76 ± 8.5; B = 83 ± 17) is thus determined by the 'specific food form' of spaghetti, rather than the type of wheat used in its manufacture. The hydrogen breath test performed on 9 subjects over an 8-hr period revealed a higher level of incomplete carbohydrate absorption after durum wheat spaghetti H2AUC(6-8h)A=141.8 ± 53 vs B=93.8 ± 36 ppm; p<0.024. In vitro digestion with alpha-amylase showed that product A had a slower kinetics of hydrolysis. These findings, plus the results of a scanning electron microscope study of both types of pasta after cooking, suggest that in addition to the specific food form of spaghetti, the gluten/starch interactions related to gluten quality contribute to reduced starch bioavailability, slow and incomplete digestion, and hence low carbohydrate absorption. However, it seems, at least in the acute conditions of this study, that the moderate glycaemic index of spaghetti is not explained by the type of wheat used in its production.
Article
The aim of the present meta-analysis was to investigate the long-term effects of glycemic index-related diets in the management of obesity with a special emphasis on the potential benefits of low glycemic index/load (GI/GL) in the prevention of obesity-associated risks. Electronic searches for randomized controlled trials (RCTs) comparing low glycemic index/load versus high glycemic index/load diets were performed in MEDLINE, EMBASE and the Cochrane Library. Outcome of interest markers included anthropometric data as well as biomarkers of CVD and glycemic control. Study specific weighted mean differences were pooled using a random effect model. 14 studies were included in the primary meta-analysis. Weighted mean differences in change of C-reactive protein [WMD: -0.43 mg/dl, (95% CI -0.78 to -0.09), p = 0.01], and fasting insulin [WMD: -5.16 pmol/L, (95% CI -8.45 to -1.88), p = 0.002] were significantly more pronounced in benefit of low GI/GL diets. However decrease in fat free mass [WMD: -1.04 kg (95% CI -1.73 to -0.35), p = 0.003] was significantly more pronounced following low GI/GL diets as well. No significant changes were observed for blood lipids, anthropometric measures, HbA1c and fasting glucose. Sensitivity analysis was performed for RCTs excluding subjects with type 2 diabetes. Decreases in C-reactive protein and fasting insulin remained statistically significant in the low GI/GL subgroups. The present systematic review provides evidence for beneficial effects of long-term interventions administering a low glycemic index/load diet with respect to fasting insulin and pro-inflammatory markers such as C-reactive protein which might prove to be helpful in the primary prevention of obesity-associated diseases.
Article
Objective: Several studies assessed the effect of glycemic index (GI) and glycemic load (GL) on energy intake in children but findings are not consistent in this regard. The aim of this study is to summarize and assess the evidence for the effect of GI and GL on energy intake by conducting a meta-analysis on published randomized clinical trials. Method: Our search process was conducted in PUBMED, Web of Science, and Google Scholar databases. The following keywords were searched in any part of published articles: "glycemic index" OR "glycaemic index" OR "glycemic load" OR "glycaemic load" OR "energy intake" AND "child" OR "children" OR "adolescent" OR "youth." Results: We gathered 5099 articles. Non-clinical trial studies that did not intervene by GI or GL or those not assessing energy intake as a dependent variable and those that were conducted on patients over age 18 y were excluded. Each included study was evaluated three times and the exclusion criteria was checked. Eventually, six studies from 1999 to 2012 met the criteria (213 participants ages 4-17.5 y). There is heterogeneity in the study's participants in the present paper. Children with type 2 diabetes, obesity, or normal-weight children were recruited in different studies. Overall effect of consuming low GI (LGI) and low GL (LGL) meals on energy intake was not significant. Subgroup analysis showed that LGI (not LGL) meals decreased subsequent energy intake, whereas heterogeneity was significant in the LGI group of studies. Although a slight asymmetry was shown by Begg's funnel plot, the Egger's asymmetry was not significant. We did not find any evidence of publication bias for studies assessing the effect of low GI or GL meals on energy intake. Conclusion: Consuming LGI diet (not LGL) has favorable effect on reducing energy intake and obesity, subsequently.
Article
The World Health Organization (WHO) has recommended that trans fatty acid (TFA) intake should be less than 1% of total energy intake, but few data are available as to the influence of energy TFA intake of as low as 1% on blood cholesterol levels. A randomized, double-blind, parallel trial was conducted to assess the effects of 1% TFA dietary supplementation on serum cholesterol levels in healthy young women. Sixty-five volunteers consumed cookies containing 1% (TFA) or 0.04% (control) energy of TFA for 4 weeks and blood was harvested after overnight fasting. There were no significant differences in serum LDL- or HDL-cholesterol levels between the two groups. The hemoglobin A1c level was not influenced by dietary TFA. These results suggest that energy of TFAs at less than 1% has little effect on serum cholesterol or hemoglobin A1c levels in healthy young women. This confirms the correctness of the WHO recommendation.