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Food and Nutrition Sciences, 2015, 6, 386-390
Published Online March 2015 in SciRes. http://www.scirp.org/journal/fns
http://dx.doi.org/10.4236/fns.2015.63039
How to cite this paper: Buosi, W., et a l. (2015) Effect of High-Protein Breakfast Meals on Within-Day Appetite and Food In-
take in Healthy Men and Women. Food and Nutrition Sciences, 6, 386-390. http://dx.doi.org/10.4236/fns.2015.63039
Effect of High-Protein Breakfast Meals on
Within-Day Appetite and Food Intake in
Healthy Men and Women
William Buosi1, David M. Bremner1, Graham W. Horgan2, Claire L. Fyfe1,
Alexandra M. Johnstone1
1Rowett Institute of Nutrition and Health, University of Aberdeen, Aberdeen, UK
2Biomathematics and Statistics Scotland, Aberdeen, UK
Email: alex.johnstone@abdn.ac.uk
Received 24 February 2015; accepted 14 March 2015; published 17 March 2015
Copyright © 2015 by authors and Scientific Research Publishing Inc.
This work is licensed under the Creative Commons Attribution International License (CC BY).
http://creativecommons.org/licenses/by/4.0/
Abstract
Breakfast is considered an important meal for daily appetite control. We examined the effect of
high-protein breakfasts on within-day appetite sensations and subsequent ad libitum intake, in
men and women. Twenty subjects attended on 4 occasions, to consume in a randomised order
high-protein (30% energy) breakfast meals, as, 1) maintenance (MTD) fed to energy requirements
(2.67 MJ), 2) a weight-loss (WL) bacon-based meal breakfast (WL-B, 2.13 MJ), 3) a WL-chicken
salad (WL-CS, 2.13 MJ) and 4) a WL-smoothie (WL-S, 2.08 MJ). The 3 HP-WL breakfasts elicited dif-
ferences in hunger (p = 0.007), fullness (p = 0.029), desire to eat (p = 0.006) and prospective con-
sumption (p = 0.020). The WL-B meal reduced hunger (p = 0.002) and enhanced fullness (p = 0.02),
compared with the two other WL breakfasts. Although these differences were not reflected in ad
libitum energy intake later in the day, a HP breakfast can modify morning satiety, which is impor-
tant during dieting.
Keywords
Protein, Appetite, Weight Loss, Breakfast Meals, Lunch Intake
1. Introduction
The effects of breakfast presentation (type and composition) on appetite remain unclear. Regular breakfasts are
recommended as a strategy to help individuals achieve and maintain a healthy body weight [1]. Missing break-
fast causes hormonal and metabolic, and compensatory changes in appetite later in the day [2]. Nutrient compo-
W. Buosi et al.
387
sition of the breakfast may also impact total daily energy intake. Dietary protein is the most satiating macronu-
trient, an effect amplified during dieting [3]. Moreover, it has been suggested that protein is more satiating at
breakfast than at other meal times [4].
However, most short-term (within-day) studies have used covert diet manipulation (e.g. liquid dairy based
pre-load) whereby the ingredients are hidden to participants [2], so that pre-ingestion cues do not influence sa-
tiety. A number of studies have covertly studied the effect of different types of proteins on satiety [5]. Fewer data
compare sources of breakfast protein fed as recognisable, individual food items [6], as meals [7], or even as
snacks [8]. Therefore it is unclear whether combination of different types of protein, fed as meals, can influence
subjective motivation to eat at breakfast time and ad libitum food intake later in the day during dieting. The
purpose of this study was therefore to compare the effects of consuming high-protein weight loss (WL) meals on
appetite responses, in men and women.
2. Participants and Methods
Twenty non-smoking healthy subjects (15 female and 5 male) were recruited from poster advertisement. All vo-
lunteers had sedentary jobs. Average age was 29.2 years (SEM 2.4) and BMI 24.8 kg∙m−2 (SEM 1.3). Eighteen
volunteers who consumed a breakfast meal before 9 am on weekdays and before noon at weekends, were classi-
fied as habitual breakfast eaters. All subjects gave written informed consent, reviewed by the Rowett Ethics
Committee. The test meals contained, 30% protein, 40% carbohydrate and 30% fat as energy, as 1) maintenance
meal (MTD, 2.67 MJ), fed to energy requirements containing cereal with milk, toast with jam, ham and scram-
bled eggs 2) WL-B bacon breakfast (2.13 MJ, containing cereal with milk, a warm bacon and cheese toasted
sandwich and grilled tomatoes), 3) WL-C (chicken salad, 2.13 MJ) and 4) WL-S as a fruit dairy smoothie (2.08
MJ). The subjects’ energy requirements (ER) were estimated as 1.3 × measured resting metabolic rate [9] (RMR),
using a ventilated hood. The MTD and WL meals were fed to 30% ER and 30% RMR, respectively. Volunteers
recorded subjective motivation to eat and meal pleasantness using half-hourly visual analogue scales (VAS) as
described previously [10]. Volunteers were then asked to stay within the research centre and were instructed to
keep a low level of physical activity. The fact that all breakfasts were high in protein and fed to WL or mainten-
ance requirements was hidden from the volunteers. Participants were made aware that two hours after breakfast,
they could snack from a buffet. This was a selection of sweet and savoury, high-calorie and low-calorie 26 ready-
to-eat foods including crisps, yoghurt, cheese, biscuits, sandwiches, fruit, ready meals, soup and vegetables,
which were stored in a designated individual refrigerator. The investigator met volunteers in the Human Nutri-
tion Unit dining room 5 hours after breakfast for lunch presenting them again with the lunch selection, ensuring
the volunteers could locate all the items that were on offer or could get more items if required. An analysis of
variance (ANOVA) was carried out with terms for volunteer, day order and breakfast type, using Genstat 13.2
(VSN International Limited).
3. Results
3.1. Appetite Response (Figure 1(a) and Figure 1(b))
There was a difference between the 3 HPWL breakfasts in hunger (p = 0.007), fullness (p = 0.029), desire to eat
(p = 0.006) and prospective consumption (p = 0.020). The HPWL-bacon breakfast reduced hunger (p = 0.002),
and enhanced fullness (p = 0.02) (Figure 1(a) and Figure 1(b)) compared to the other two WL breakfasts. In-
deed, both hunger and fullness on the WL-B diet were similar to that for the higher energy containing mainten-
ance breakfast (MTD). Subjects did not seem to perceive the caloric restriction when consuming the HPWL-
bacon breakfast. Compared with the maintenance meal (MTD) subjects were more hungry (p = 0.001) and less
full (p = 0.003) after the WL-Smoothie and WL-CS breakfasts. Post-meal ratings reported similar pleasantness
(p = 0.379) for all meals.
3.2. Ad libitum Food Intake (Table 1)
All the foods and drinks that were consumed between 2 and 5 hours, or between 5 and 6 hours after breakfast
were classified, respectively, as snack or lunch intake. Despite differences in motivation to eat, subjects did not
change ad libitum combined snack and lunch energy intake (p = 0.922) (Table 1). Subjects did consume less
snack energy intake after MTD breakfast (p = 0.032), in comparison to the WL breakfasts, but total energy in-
W. Buosi et al.
388
(a)
(b)
Figure 1. (a) Plot of mean (±SEM) hunger (mm), as assessed with Visual Ana-
logue Scales after consumption of a maintenance breakfast (BF) (), a weight-
loss (WL) cooked breakfast (), a WL chicken salad BF () and a WL smoothie
BF (); (b) Plot of mean (±SEM) fullness (mm), as assessed with Visual Ana-
logue Scales after consumption of a maintenance breakfast (BF) (), a weight-
loss (WL) cooked breakfast (), a WL chicken salad BF () and a WL smoothie
BF ().
take (breakfast, lunch and snack combined) across the morning did not change significantly (p = 0.285).
4. Discussion
We investigated the effects of different sources of high-protein WL breakfasts provided as recognisable meals,
on subjective appetite and energy intake and compared the response to a maintenance diet. The WL-bacon
breakfast enhanced fullness and reduced hunger to a similar extent as the maintenance breakfast, compared to
the WL-chicken salad and the WL-smoothie meals. Many studies that investigated appetite responses to food
manipulation use the test meal paradigm, providing preloads to participants. In the present study, familiar food
items were provided and the size of the breakfast was individualized with respect to energy requirements, based
on metabolic rate. The warm cooked breakfast meal based on meat protein was more satiating than the dairy or
chicken rich sources, despite similar nutrient profile. Dietary proteins from different sources have been shown to
influence satiety [6]. They found that fish was more satiating than the other sources of proteins which included
W. Buosi et al.
389
Table 1. Mean intakes at the fixed breakfasts, ad libitum snacks, lunch, and total (in MJ) after weight
loss and maintenance high-protein breakfasts.
Meal
Intervention breakfasts
SEM p p* Weight-loss MTD
WL-B WL-CS WL-S
Breakfast 2.13 2.13 2.08 2.67 0.049 <0.001 0.505
Snack and lunch intake 4.04 4.16 4.04 3.97 0.279 0.922 0.885
Of which snacks 0.61 0.62 0.60 0.34 0.032a 0.626
Total morning intake 6.17 6.29 6.12 6.64 0.289 0.285 0.837
ap-value for snack was calculated from the log values of the intakes as their distribution was skewed. p* is the p-value as-
sociated to the analysis of variance performed for the three weight-loss diets only.
beef and chicken. The acute effect of different liquid protein sources has been investigated [11], with the area
under the curve for hunger lower for a whey meal than with the tuna, egg and meat meals. In our study, volun-
teers felt significantly less hungry after the cooked breakfast than after the dairy smoothie and the cold chicken
salad meal. The literature indicates that amino acid composition, rate of absorption, and protein/food texture
may be important factors for protein-induced-satiety [12]. On balance, evidence from studies where manipula-
tions were covert suggests that amount of protein is more important than the type [7].
In addition to the metabolic responses to different nutrients, psychological factors can also influence both
perception and physiological function. For example, food presentation is a useful parameter to influence appetite
during weight loss. It has been previously reported that telling consumers about nutritional profile influences gut
hormone release, even when the same food is actually served [13]. In our study, the warm cooked meal gave the
greatest response in fullness, which was comparable to the maintenance breakfast. It may be that subjects perce-
ive or expect [14] a cooked breakfast to be more satiating than a dairy and fruit smoothie or a cold chicken salad
meal.
Liquid versus solid breakfast types may have an influence on appetite due to gastric rate of delivery and re-
lease of gut hormones in response. In adults, a study found that the satiating power of protein was stronger when
consumed in a solid form with water than when consumed a liquid form [15]. Foods high in carbohydrate and
high in fat also seem to be more satiating when ingested as a solid than as a liquid [16]. This has been suggested
to be valid in adolescents where volunteers reported lower appetite, as in our study, during two hours after a
protein-rich solid breakfast compared to a liquid version [17].
It has been shown that breakfast consumers lost more weight when they did not eat breakfast, and conversely,
those who regularly skipped breakfast lost more weight when they were made to eat a standard breakfast, which
suggests that changing the usual eating pattern may have a greater effect than breakfast per se in those aiming to
lose weight [18]. The effect of omitting breakfast in regular eaters as opposed to reintroducing breakfast to those
who skip breakfast both report similar effects in regard to energy intake. In our study, volunteers were regular
breakfast eaters and results may be different for those who do not habitually consume breakfast.
5. Conclusion
These findings provide insight into the effects of breakfast meals on appetite and suggest that further research is
warranted. Breakfast meal type is an important choice influencing morning motivation to eat during weight
loss.
Acknowledgements
The Rowett Institute and Biomathematics and Statistics Scotland are grateful to the Scottish Government for
funding this work. We thank the Rowett Human Nutrition Unit staff for their technical help with the interven-
tions. Staff members who helped include Jean Bryce, Nina Lamza and Karen Taylor.
The Rowett Institute and Biomathematics and Statistics Scotland are grateful to the Scottish Government for
funding this work.
W. Buosi et al.
390
References
[1] Astbury, N.M., Taylor, M.A. and Macdonald, I.A. (2011) Breakfast Consumption Affects Appetite, Energy Intake, and
the Metabolic and Endocrine Responses to Foods Consumed Later in the Day in Male Habitual Breakfast Eaters. Jour-
nal of Nutrition, 141, 1381-1389. http://dx.doi.org/10.3945/jn.110.128645
[2] Bendtsen, L.Q., Lorenzen, J.K., Bendsen, N., Rasmussen, C. and Astrup, A. (2013) Effect of Dairy Proteins on Appe-
tite, Energy Expenditure, Body Weight, and Composition: A Review of the Evidence from Controlled Clinical Trials.
Advances in Nutrition, 4, 418-438. http://dx.doi.org/10.3945/an.113.003723
[3] Astrup, A. (2005) The Satiating Power of Protein—A Key to Obesity Prevention? American Journal of Clinical Nutri-
tion, 82, 1-2.
[4] Leidy, H.J., Bossingham, M.J., Mattes, R.D. and Campbell, W.W. (2009) Increased Dietary Protein Consumed at
Breakfast Leads to an Initial and Sustained Feeling of Fullness during Energy Restriction Compared to Other Meal
Times. British Journal of Nutrition, 101, 798-803. http://dx.doi.org/10.1017/S0007114508051532
[5] Veldhorst, M.A.B., Nieuwenhuizen, A.G., Hochstenbach-Waelen, A., et al. (2009) Comparison of the Effects of a High-
and Normal-Casein Breakfast on Satiety, “Satiety” Hormones, Plasma Amino Acids and Subsequent Energy Intake.
British Journal of Nutrition, 101, 295-303. http://dx.doi.org/10.1017/S0007114508003061
[6] Uhe, A.M., Collier, G.R. and O’Dea, K. (1992) A Comparison of the Effects of Beef, Chicken and Fish Protein on Sa-
tiety and Amino Acid Profiles in Lean Male Subjects. Journal of Nutrition, 122, 467-472.
[7] Lang, V., Bellisle, F., Oppert, J., et al. (1998) Satiating Effect of Proteins in Healthy Subjects: A Comparison of Egg Al-
bumin, Casein, Gelatin, Soy Protein, Pea Protein, and Wheat Gluten. American Journal of Clinical Nutrition, 67, 1197-
1204.
[8] Dougkas, A., Minihane, A.M., Givens, D.I., Reynolds, C.K. and Yaqoob, P. (2012) Differential Effects of Dairy Snacks
on Appetite, but Not Overall Energy Intake. British Journal of Nutrition, 108, 2274-2285.
http://dx.doi.org/10.1017/S0007114512000323
[9] National Research Council (1989) Energy. In: Recommended Dietary Allowances, 10th Edition, National Academies
Press, Washington DC, 24-38.
[10] Flint, A., Raben, A., Blundell, J.E. and Astrup, A. (2000) Reproducibility, Power and Validity of Visual Analogue Scales
in Assessment of Appetite Sensations in Single Test Meal Studies. International Journal of Obesity, 24, 38-48.
http://dx.doi.org/10.1038/sj.ijo.0801083
[11] Pal, S. and Ellis, V. (2010) The Acute Effects of Four Protein Meals on Insulin, Glucose, Appetite and Energy Intake
in Lean Men. British Journal of Nutrition, 104, 1241-1248. http://dx.doi.org/10.1017/S0007114510001911
[12] Anderson, G.H., Tecimer, S.N., Shah, D. and Zafar, T.A. (2004) Protein Source, Quantity, and Time of Consumption
Determine the Effect of Proteins on Short-Term Food Intake in Young Men. Journal of Nutrition, 134, 3011-3015.
[13] Crum, A.J., Corbin, W.R., Brownell, K.D. and Salovey, P. (2011) Mind over Milkshakes: Mindsets, Not Just Nutrients,
Determine Ghrelin Response. Health Psychology, 30, 424-429. http://dx.doi.org/10.1037/a0023467
[14] Brunstrom, J.M., Brown, S., Hinton, E.C., Rogers, P.J. and Fay, S.H. (2011) “Expected Satiety” Changes Hunger and
Fullness in the Inter-Meal Interval. Appetite, 56, 310-315. http://dx.doi.org/10.1016/j.appet.2011.01.002
[15] Martens, M.J.I. and Westerterp-Plantenga, M.S. (2012) Mode of Consumption Plays a Role in Alleviating Hunger and
Thirst. Obesity, 20, 517-524. http://dx.doi.org/10.1038/oby.2011.345
[16] Mourao, D.M., Bressan, J., Campbell, W.W. and Mattes, R.D. (2011) Effects of Food Form on Appetite and Energy In-
take in Lean and Obese Young Adults. International Journal of Obesity, 31, 1688-1695.
http://dx.doi.org/10.1038/sj.ijo.0803667
[17] Leidy, H.J., Bales-Voelker, L.I. and Harris, C.T. (2011) A Protein-Rich Beverage Consumed as a Breakfast Meal
Leads to Weaker Appetitive and Dietary Responses v. a Protein-Rich Solid Breakfast Meal in Adolescents. British
Journal of Nutrition, 106, 37-41. http://dx.doi.org/10.1017/S0007114511000122
[18] Schlundt, D.G., Hill, J.O., Sbrocco, T., Pope-Cordle, J. and Sharp, T. (1992) The Role of Breakfast in the Treatment of
Obesity: A Randomized Clinical Trial. American Journal of Clinical Nutrition, 55, 645-651.
