Dose–response effects of a novel fat emulsion
(OlibraTM) on energy and macronutrient intakes up to
AA Burns1, MBE Livingstone1*, RW Welch1, A Dunne2and IR Rowland1
1The Northern Ireland Centre for Diet and Health, University of Ulster, Coleraine, Co Londonderry, Northern Ireland, UK; and
2Department of Statistics, University College Dublin, Ireland
Objective: To investigate the dose–response effects of a novel fat emulsion (OlibraTM) on energy and macronutrient intakes up
to 36h post-consumption in non-overweight subjects.
Design: A single-blind, placebo-controlled, within-subject cross-over design was used.
Setting: Metabolic suite of the University of Ulster, Coleraine.
Subjects: Fifty subjects (30 female, 20 male) from the student and staff population of the University of Ulster, Coleraine.
Interventions: Subjects were given in random order, 7 days apart, a 200g portion of yoghurt containing a total of 15g of fat,
which varied in quantity of OlibraTMfat (0, 2, 4, 6g) at 09:00h. At 13:00h subjects were given ad libitum access to a range of
foods. Amounts of food consumed were measured by covert pre- and post-consumption weighing of individual serving dishes.
For the remainder of the day and the following 24h, subjects weighed and recorded all food intakes.
Results: Relative to the control yoghurt, mean energy (7.42 vs 5.83, 5.60, 5.24MJ), fat (97.4 vs 74.4, 74.2, 67.5g; 48.8 vs 46.8,
48.9, 47.6% energy), protein (59.1 vs 50.0, 44.0, 40.8g; 13.2 vs 13.9, 12.9, 12.8% energy), and carbohydrate (171.5 vs 140.9,
130.2, 126.0g; 38.0 vs 39.3, 38.2, 39.6% energy), intakes were progressively reduced with increasing doses of OlibraTMfat in
the total group (P<0.001). A similar response was observed in the female group up to 4g (P<0.001) and in the male group
after 2 and 6g (P<0.05). Energy and macronutrient intakes for the remainder of each study day and over the following 24h
were significantly lower after all dose levels compared to the control (P<0.001).
Conclusion: The results suggest that OlibraTMfat reduced the effect of overeating during an ad libitum lunch meal and
subsequent food intake up to 36h post-consumption.
Sponsorship: Scotia Pharmaceuticals Limited.
European Journal of Clinical Nutrition (2002) 56, 368–377. DOI: 10.1038=sj=ejcn=1601326
Keywords: fat; emulsions; energy intake; satiety
Although current research suggests that fat is the least
satiating of the macronutrients (Rolls & Hammer, 1995),
the issue remains unresolved (Welch et al, 1988; de Graaf
et al, 1992; Blundell et al, 1996). It is possible that metho-
dological differences between study designs may have con-
tributed to this controversy (Rolls et al, 1988; de Graaf et al,
1992). Differences in meal type (Kissileff, 1984), energy
density and macronutrient composition (Prentice & Poppitt,
1996; Westerterp-Plantenga et al, 1996; Bell et al, 1998),
duration of time between a preload and a test meal (Rolls
et al, 1991a; Horn et al, 1996; Melanson et al, 1999) and
characteristics of subject populations (Drewnowski et al,
1985; Mela & Sacchetti, 1991) have all been shown to
influence the satiating efficiency of fat. Furthermore, differ-
ent physicochemical properties of fats could influence their
satiating properties. These include fatty acid chain length
(Bach et al, 1996; Stubbs & Harbon, 1996; Van Wymelbeke
*Correspondence: MBE Livingstone, Northern Ireland Centre for Diet and
Health, University of Ulster, Coleraine, Co Londonderry, Northern Ireland
BT52 1SA, UK.
Guarantor: MBE Livingstone.
Contributors: AAB executed the practical work and took overall
responsibility for writing the paper. MBEL and RWWare grant holders
and assisted in devising the study protocol and writing the paper. AD
carried out the statistical analysis. IRR is a grant holder and assisted in
writing the paper.
Received 18 June 2001; revised 29 August 2001;
accepted 6 September 2001
European Journal of Clinical Nutrition (2002) 56, 368–377
? 2002 Nature Publishing Group All rights reserved 0954–3007/02 $25.00
et al, 1998), degree of fatty acid unsaturation (Shimomura
et al, 1990; Lawton et al, 1997; Kamphuis et al, 2001), degree
of emulsification (Welch et al, 1985, 1988) and emulsion
stability (Armand et al, 1992). In this context it has recently
been shown that a fat emulsion (OlibraTM) formulated from
palm oil and oat oil fractions significantly decreased energy
and macronutrient intakes in lean, overweight and obese
subjects up to 36h post-consumption (Burns et al, 2000,
2001). The aim of the present study is to investigate if the
responses to this novel fat emulsion and the subsequent
effects of these on food intakes are dose-dependent.
Subjects and methods
Fifty subjects (30 females, 20 males) were recruited by poster
advertisement from the student and staff population at the
University of Ulster. The study protocol was explained in
detail to each subject, and the subjects who met the elig-
ibility criteria and agreed to take part gave their written
informed consent. Inclusion criteria were: body mass index
(BMI) 20–25kg=m2, non-smokers, non-vegetarians, non-
restrained eaters as assessed by the Dutch Eating Behaviour
Questionnaire (Van Strien et al, 1986), not taking any pre-
scription medication and non-participants in any previous
study using OlibraTMfat. The weight, height and percentage
body fat (bioelectrical impedance Bodystat 1500, Bodystat
Ltd, Isle of Man, UK) of each subject were measured prior to
breakfast on the first study day. The study was approved by
the Research Ethical Committee of the University of Ulster.
This study was conducted over 3 months in the metabolic
suite at the University of Ulster. The metabolic suite consists
of a food preparation area, which is separate from an inde-
pendent dining area, where six subjects can eat comfortably.
The study design was a randomised, single-blind, placebo-
controlled, within-subject cross-over. Each subject was stu-
died on four occasions, on the same day of each week, and
with a one-week interval between study days. Each subject
came to the metabolic suite at 18:00h on the evening prior
to each study day and consumed (on each occasion) the
same evening meal in terms of weight of food, energy and
macronutrient composition. Subjects were asked to refrain
from moderate-to-heavy exercise on each study day and on
the day before and the day after each study day. After the
evening meal prior to each study day, subjects were
requested to fast from 20:00h until 08:45h the following
day, when they came to the metabolic suite and consumed a
200g portion of yoghurt containing varying doses of Oli-
braTMfat or a control containing only milk fat. After eating
the yoghurt, subjects remained in the metabolic suite and
were not permitted to consume anything other than uncar-
bonated water, if required. At 13:00h subjects were given ad
libitum access to a range of sweet and savoury foods compa-
tible with the stated food preferences of the subjects. Uncar-
bonated water was available to drink at meal times. All foods
presented at 13:00h were covertly weighed prior to the meal,
and all uneaten food was weighed after the meal when the
subjects had left the metabolic suite. Intakes were assessed by
difference. After the lunch meal subjects were free to leave
the metabolic suite. For the remainder of the day, and up
until 21:00h the following day, subjects were permitted to
eat and drink as they wished, but were instructed to keep a
weighed record of all food and beverages consumed during
this period using a set of weighing scales (Digital Scale,
Model 308, Ravencourt Ltd, UK) and a food diary.
for energy and macronutrient content (1165kJ, 6.8g protein,
15g fat, 28.8g carbohydrate per 200g portion). Depending
on the dose, the 15g of fat comprised a combination of
fat emulsion (Scotia LipidTeknik, Stockholm,
Sweden) and=or milk fat. The doses of OlibraTMfat emulsion
were 5, 10 and 15g, which corresponded to a content of 2, 4
and 6g of OlibraTMfat, respectively. The control yoghurt
contained 15g of milk fat (40% fat emulsion). OlibraTMfat is
a food ingredient containing fractionated palm oil and
fractionated oat oil in the proportions 95:5, dispersed in
water to give a total fat content of 42% (w=w). The percen-
tage fatty acid composition of OlibraTMfat compared to milk
fat is as follows: palmitic (16:0), 42.1 vs 26.8; stearic (18:0),
4.3 vs 11.5; other saturates, 2.1 vs 25.8; oleic (18:1), 40.1 vs
28.7; linoleic (18:2), 10.4 vs 1.4; and other unsaturates, 1.0 vs
5.8. The yoghurt was supplied by Skane Mejerier, Lunnarp,
The composition of all yoghurts was matched
The lunch meal was a buffet-style, self-selection meal that
allowed ad libitum consumption of a variety of foods that
varied in macronutrient composition (Table 1). All foods
were served in larger than estimated average portions so
that choice was not restricted by quantity. Different types
of food were served in separate serving dishes so as not to
influence food combination choices. Unlimited eating time
was given to each subject. Uncarbonated water was available
Assessment of appetite
Subjects rated their hunger, desire to eat and perceived full-
ness on visual analogue scales (VAS; in mm) by the pen and
paper method. For example, hunger was rated on a 100mm
line preceded by the question ‘How hungry do you feel?’ and
anchored on the left by ‘not at all hungry’ and on the right
by ‘as hungry as I have ever felt’. The other anchors for the
questions on desire to eat and perceived fullness consisted of
the phrases ‘very weak...’ against ‘very strong...’, and ‘not
Dose–response effect of OlibraTM
AA Burns et al
European Journal of Clinical Nutrition
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Dose–response effect of OlibraTM
AA Burns et al
European Journal of Clinical Nutrition