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Effect on Body Weight of Replacing Dietary Fat with
Olestra for Two or Ten Weeks in Healthy Men and
Women
a
a
a
a
Heli J. Roy PhD , Marlene M. Most PhD , Andrea Sparti PhD , Jennifer C. Lovejoy PhD ,
a
b
a
Julia Volaufova PhD , John C. Peters PhD & George A. Bray MD
a
Pennington Biomedical Research Center, Louisiana State University, Baton Rouge,
Louisiana (H.J.R., M.M.M., A.S., J.C.L., J.V., G.A.B.)
b
Regulatory and Clinical Development, The Procter & Gamble Co., Cincinnati, Ohio
(J.C.P.)
Published online: 24 Jun 2013.
To cite this article: Heli J. Roy PhD, Marlene M. Most PhD, Andrea Sparti PhD, Jennifer C. Lovejoy PhD, Julia Volaufova
PhD, John C. Peters PhD & George A. Bray MD (2002) Effect on Body Weight of Replacing Dietary Fat with Olestra
for Two or Ten Weeks in Healthy Men and Women, Journal of the American College of Nutrition, 21:3, 259-267, DOI:
10.1080/07315724.2002.10719219
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Original Research
Effect on Body Weight of Replacing Dietary Fat with
Olestra for Two or Ten Weeks in Healthy Men
and Women
Heli J. Roy, PhD, Marlene M. Most, PhD, Andrea Sparti, PhD, Jennifer C. Lovejoy, PhD, Julia Volaufova, PhD,
John C. Peters, PhD, and George A. Bray, MD
Pennington Biomedical Research Center, Louisiana State University, Baton Rouge, Louisiana (H.J.R., M.M.M., A.S., J.C.L., J.V.,
G.A.B.), Regulatory and Clinical Development, The Procter & Gamble Co., Cincinnati, Ohio (J.C.P.)
Key words: body weight, dietary fat, energy intake, fat substitute
Objective: To examine in two separate studies the effects of replacing dietary fat with Olestra on body
composition and weight change in healthy young men and women.
Methods: Ten healthy, lean young men participated in Study One that was a 22-day single blind,
within-subject design. After a control diet (40% fat) for eight days Study One subjects received an Olestra-
substituted diet (31% metabolizable fat) for 14 days. Study Two was a randomized parallel-arm clinical trial with
1
5 healthy, lean and overweight young women. These subjects were randomly assigned to receive a control diet
(40% fat), an Olestra-containing diet (31% metabolizable fat) or a reduced-fat diet (31% fat) for 10 weeks. All
foods were provided to the subjects, and energy intakes were not restricted. The primary endpoint in both studies
was change from baseline in body weight. In Study Two, body composition was measured by dual energy x-ray
absorptiometry. In both studies, food intake and nutrient compensation were assessed.
Results: In Study One fat substitution by Olestra resulted in a significant 1.7 kg weight loss from baseline.
In Study Two, change in body weight and body fat from baseline were statistically significant in all groups, but
the group with Olestra lost significantly more weight from baseline (Ϫ5.0 kg) than the other two groups. In Study
One there was partial compensation for the decreased energy intake, while in Study Two, compensation was seen
only for those on the reduced-fat diet.
Conclusion: Replacement of 1⁄
of dietary fat with Olestra in periods of up to 10 weeks results in weight loss
3
in men and women.
several short-term clinical trials have shown that low fat diets
INTRODUCTION
promote weight loss (reviewed in [1]).
Dietary fat has been implicated in the development of
obesity [1–4]. In a cross-cultural comparison, dietary fat and
obesity are strongly associated [1]. Within-country data also
illustrate that as the level of fat in the diet increases, the
prevalence of obesity increases [5,6]. Because fat is highly
energy dense, diets that are high in fat are typically high-energy
as well. In the absence of adequate physical activity, high-
energy diets promote obesity. Whether reducing dietary fat is a
useful strategy in the treatment of obesity is less clear, although
Olestra provides a valuable tool with which to explore the
changes in metabolism and food intake when energy density of
the diet is covertly reduced without altering the mass or mouth-
feel of the food. The replacement of dietary fat with Olestra
produces an energy deficit that must be met by mobilizing fat
reserves or by increasing food intake if weight loss is to be
prevented. If the energy deficit produced by reducing metabo-
lizable energy from fat is detected when other properties of the
diet remain the same, then compensation might be expected to
Heli J. Roy, PhD, is presently at Louisiana State University Agricultural Center, Baton Rouge, Louisiana. Andrea Sparti, PhD, is presently at the Swiss Federal Office of
Public Health, Bern, SWITZERLAND. Preliminary data were presented at the Experimental Biology meetings (FASEB J 11:A358, 1997; 9:A439, 1995) and the American
Society for Clinical Nutrition meeting (Am J Clin Nutr 61:902, 1995).
Address reprint requests to: Marlene M. Most, PhD, RD, FADA, Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808. E-mail:
mostmm@pbrc.edu
Journal of the American College of Nutrition, Vol. 21, No. 3, 259–267 (2002)
Published by the American College of Nutrition
2
59

Replacing Fat with Olestra Effect on Body Weight
result in an increase in food intake. Previous studies examining
the impact of Olestra on energy balance suggest that energy
deficits on Olestra-containing diets are poorly compensated and
could lead to weight loss [7]. However, previous studies were
all short-term and investigations of effects of Olestra on sub-
strate oxidation are lacking. We examined these concepts in
two separate studies. In the first study, the effects of replacing
dietary fat with Olestra were examined in young men who
spent two periods of two days each in a metabolic chamber
where the short-term effects of Olestra on fat oxidation and
total energy expenditure could be measured. Only the weight
change and food intake data are reported here. The observation
of weight loss in the two-week interval between the two respi-
ratory chamber stays in Study One prompted the second 12-
week study of Olestra in a group of lean and obese females.
Experimental Design
Study One. During the first eight days all subjects received
a control diet prior to entering the respiration chamber. After
the first 24 hours in the chamber, the diet was modified by the
replacement of 1⁄
of the fat with Olestra. After an additional 24
3
hours, the subjects were discharged and given the Olestra-
substituted diet as outpatients for an additional 14 days. For the
final two days the subjects stayed in the respiration chamber to
evaluate metabolic rate and fat oxidation (data not reported
here). The energy needs for each subject were calculated before
preparing their diets. The control diet brought all subjects to the
same macronutrient composition prior to the experimental diet,
so that each subject’s habitual diet would not confound the
results. Body weight, without shoes and in light indoor cloth-
ing, was measured weekly in the morning, in the fasting state,
and after voiding, using a calibrated electronic scale (National
Control, model 3003, Santa Rosa, CA). Initial body composi-
tion was assessed by dual energy x-ray absorptiometry (Ho-
logic, QDR2000, Waltham, MA). All subjects could eat as
much of the Olestra-containing diet as they wished during the
outpatient period, and no effort was made to modify their
intake.
Study Two. This was a randomized controlled trial with
three parallel arms. During the first week all subjects consumed
the control diet. They were then randomly assigned to one of
three diets (the control diet, the Olestra-substituted diet or the
reduced-fat diet containing the same metabolizable fat as in the
Olestra-substituted diet) for 10 to 12 weeks. The variation in
total study length for the women occurred due to the fact that
the endpoint tests were performed at the same time of the
menstrual cycle phase as baseline testing. Body weight was
measured as in Study One, while lean body mass and fat mass
were assessed at the beginning, middle and end of the study by
dual energy x-ray absorptiometry (DXA). Although the sub-
jects were randomly assigned to the diet arms, an imbalance in
starting body weight occurred, and, as by chance, only lean
subjects were randomized to the reduced-fat arm.
METHODS
Subjects
Study One. Ten lean, healthy young men, ages 18 to 35
2
years, with a body mass index (BMI) of Ͻ25 kg/m were
recruited to participate in a study using the respiration chamber
where the effects of acute replacement with Olestra on meta-
bolic rate and fat oxidation could be assessed. They were
weight stable within 1 kg for the six months prior to the study.
The subjects were not restrained eaters as measured by the
Three Factor Eating Questionnaire [8], and they regularly ate
three meals a day. Men were excluded if they had eating
disorders, a family history of obesity or diabetes, had chronic
illness, were taking medications, were dieters or experienced
weight cycles, or were consuming vegetarian or unusual diets.
Smokers and athletes also were excluded.
Study Two. Eighteen healthy, young women, aged 18 to 30
2
years, with a BMI of 21 to 35 kg/m were recruited. They were
weight stable for six months prior to the study, and regularly ate
three meals a day. Women who were highly restrained eaters
based on the Three Factor Eating Inventory [8] were excluded
from the study. Additional factors for exclusion were diabetes,
smoking, vegetarianism, athletic training, and medications
other than oral contraceptives, gastrointestinal (GI) problems or
surgery other than cholecystectomy or appendectomy, or a
family history of obesity. Three women dropped out prior to
completion of the study and were not used in the analyses. One
subject experienced GI symptoms with consumption of Olestra,
one had GI symptoms unrelated to Olestra, and one dropped out
for personal reasons. This left 15 subjects who completed the
study.
Diets
Study One. The control diet provided 40% of the energy as
fat, 45% as carbohydrate and 15% as protein [9]. The total fat
level was near the average intake of the population at the time
of the study. The Olestra diet had 1⁄
3
less absorbable fat than the
control diet, but equal amounts of carbohydrate and protein
Fig. 1). Therefore, the metabolizable energy was approxi-
(
mately 13% less than the control diet, and the composition of
the macronutrients changed, providing 31% of the metaboliz-
able energy from fat, 52% from carbohydrate and 17% from
protein. The Olestra diet was less energy dense than the control
diet since the same volume provided 87% of the energy pro-
vided by the control diet. The subjects knew that Olestra was to
be used during the study, but were unaware of what foods
contained it.
The Institutional Review Board of Louisiana State Univer-
sity approved both protocols and informed consent was ob-
tained from all participants.
2
60
VOL. 21, NO. 3

Replacing Fat with Olestra Effect on Body Weight
received the Olestra-substituted (Study One and Two) or re-
duced-fat (Study Two) diets, they received essentially similar
diets, but with approximately 13% less energy (e.g., approxi-
mately 270 kcal less for a 2000 kcal diet, 360 kcal less for a
2
700 kcal diet). With the availability of the free choice foods,
those subjects had the possibility to compensate for the energy
deficit. For subjects remaining on the control diet (Study Two),
free choice foods allowed them to maintain energy intake
required for weight maintenance. Although the obligatory por-
tion of the diets could have been less, this approach tightly
maintained the macronutrient content of the diets, yet provided
some leeway for compensation using free choice foods or
allowing for weight loss.
Fig. 1. Example macronutrient content of the diets for Study One.
Study Two. The control and Olestra diets were of the same
composition as in Study One. The reduced-fat diet matched the
macronutrient composition of the Olestra diet. For all three
diets, total grams of protein and carbohydrate were similar,
while total grams of metabolizable fat were similar for the
Olestra and reduced-fat diets (Fig. 2). The reduced-fat diet was
lower in total weight than the control and Olestra diets, but
since the metabolizable energy for the reduced-fat diet was
similar to the Olestra diet, their energy densities were similar
and less than the control diet. The subjects were told that
Olestra, a fat substitute was used in one arm of the study, but
they did not know who was receiving the fat substitute. All
subjects received a multi-vitamin tablet daily to maintain fat-
soluble vitamin status.
For both studies, foods in the Olestra-substituted diet
matched those of the control diet, except that 1⁄
of the fat (24
3
to 50 g/day, depending on the energy level) in the diet was
replaced by Olestra. Olestra replaced cooking oils and hydro-
genated shortening in baked products and entrees. Menus were
analyzed using the Moore’s Extended Nutrient (MENu) data-
base (Pennington Biomedical Research Foundation, Baton
Rouge, LA). Sample menus are shown in Table 1. All food was
prepared by the Metabolic Kitchen staff of the Pennington
Biomedical Research Center under the supervision of a re-
search dietitian. The subjects were required to eat two meals a
day, usually breakfast and dinner, at the center. Lunch, the
evening snack and all weekend meals were packed for take-out.
The free choice foods (crackers, muffins, dinner rolls, corn-
bread muffins and biscuits) had the same macronutrient com-
position as the overall diet. Control diet free choice foods were
For both studies, all subjects received an obligatory diet that
they were required to consume in entirety based on their initial
individualized energy intake level. Free choice foods (de-
scribed below) were available for each subject to eat as desired
to adjust their energy intake. Initial energy intake levels were
estimated for each subject from the resting metabolic rate and
multiplied by an activity factor (1.5 for Study One and 1.4 for
Study Two). Observations in our laboratory have shown that
women have a lower activity factor than men (range 1.1 to 1.7
for women vs. 1.3 to 1.85 for men) [10]. During the first week
of each study, while all subjects were on the control diet, total
energy intake was adjusted until the level required for weight
maintenance was achieved. That energy level was provided to
those on the control diet (Study Two). When the subjects
1
00 kcal each, while Olestra-containing and reduced-fat free
choice foods were 87 kcal each. Subjects received free choice
foods in excess with every meal and as snacks. They could eat
as much or as little of the free choice foods as desired. This
system allowed the subjects to freely vary their energy intake
without affecting the macronutrient composition of the diet
[11]. Non-caloric beverages were allowed ad libitum.
Use of a daily diary assessed adherence to the diet. All
participants were asked to record study foods and beverages not
consumed and non-study foods consumed. Although this is
self-reported data, which depends on the honesty of the sub-
jects, the dietary staff worked to establish an environment of
trust to promote accurate reporting. Reported deviations were
used to adjust dietary intake data.
To assess whether it was possible to detect the Olestra
included in the food, prior to the study a panel of Pennington
Biomedical Research Center staff conducted blinded paired-
sample food tasting sessions. Sensory attributes and overall
flavor acceptability for each Olestra and full-fat food product
were rated. The taste panel members were asked to identify in
each pair of foods the one they thought contained Olestra. The
results showed that it was not possible to differentiate between
the Olestra and the full-fat versions of the foods (data not
shown).
Fig. 2. Example macronutrient content of the diets for Study Two.
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION
261

Replacing Fat with Olestra Effect on Body Weight
Table 1. Sample Menus Used for Study Two
1
2
2
Control Diet
Olestra Diet
Reduced-Fat Diet
Breakfast:
Breakfast:
Breakfast:
Grapefruit juice
Crispy rice cereal
Blueberry muffins
Milk, reduced-fat
Lunch:
120.0 g
20.0 g
120.0 g
245.0 g
Grapefruit juice
Crispy rice cereal
Blueberry muffins
Milk, reduced-fat
120.0 g
20.0 g
120.0 g
245.0 g
Grapefruit juice
120.0 g
18.0 g
120.0 g
220.0 g
Crispy rice cereal
Blueberry muffins
Milk, fat-free (skim)
3
Lunch:
Lunch:
Sandwich with
Turkey breast
American cheese
White bread
Lettuce
Sandwich with
Turkey breast
American cheese
White bread
Lettuce
Sandwich with
Turkey breast
Low-fat cheese
White bread
Lettuce
82.0 g
42.6 g
50.0 g
15.0 g
45.0 g
24.0 g
39.0 g
30.0 g
71.6 g
355 mL
82.0 g
42.6 g
50.0 g
15.0 g
45.0 g
24.0 g
39.0 g
30.0 g
71.6 g
355 mL
82.0 g
42.6 g
50.0 g
15.0 g
45.0 g
24.0 g
34.0 g
43.0 g
71.6 g
355 mL
Tomatoes
Tomatoes
Tomatoes
Mayonnaise
Potato sticks
Peaches
Lemon cake
Diet soft drink
Dinner:
Shrimp creole sauce
Shrimp
Steamed rice
Margarine
Green peas
Cornbread muffin
Butter
Ice cream
Milk, reduced-fat
Snack:
Mayonnaise
Potato sticks
Peaches
Mayonnaise
Potato sticks
Peaches
Lemon cake
Diet soft drink
Dinner:
Shrimp creole sauce
Shrimp
Steamed rice
Margarine
Green peas
Cornbread muffin
Butter
Ice cream
3
Lemon cake
Diet soft drink
Dinner:
Shrimp creole sauce
Shrimp
Steamed rice
Margarine
Green peas
Cornbread muffin
Butter
Ice cream
3
145.0 g
95.0 g
60.0 g
20.0 g
80.0 g
70.0 g
10.0 g
46.0 g
245.0 g
145.0 g
95.0 g
60.0 g
20.0 g
80.0 g
70.0 g
10.0 g
46.0 g
245.0 g
145.0 g
95.0 g
60.0 g
7.5 g
76.0 g
70.0 g
0 g
3
46.0 g
235.0 g
Milk, reduced-fat
Snack:
Oatmeal cookies
Milk, fat-free (skim)
Snack:
Oatmeal cookies
3
Oatmeal cookies
34.8 g
34.8 g
34.8 g
1
2
3
Provides approximately 2600 kcalories.
Provides approximately 2253 kcalories.
Olestra-substituted recipe.
Statistical Analysis of Data
RESULTS
Study One. The response variables were analyzed using an
analysis of variance (ANOVA) with repeated measures design,
with two different types of repeated factor. One was the day
Study One. Characteristics for the 10 healthy, lean, non-
smoking, young men are shown in the left-hand column of
Table 2. Energy and nutrient intakes were affected by the
dietary manipulation (Table 3). Olestra substitution for regular
fat resulted in a significant reduction in energy intake of 244 Ϯ
(with five levels) and the other was the period (with two levels)
referring to period one as a control and period two as treatment.
In both cases the five dimensional covariance matrix of mea-
surements was modeled as unstructured.
7
6 kcal/day. No effect of time on energy intake could be
detected during the control (p ϭ 0.25) or Olestra diet (p ϭ
.13). Digestible fat intake decreased significantly going from
of
Study Two. There were two types of analysis conducted.
The repeated measures analysis was used for comparison of
two periods (weeks 0 to 4 and weeks 5 to 10), adjusted for
baseline body weight. For response variables that were taken at
baseline, midpoint and end, such as fat mass and lean body
mass, a simpler analysis was conducted, analyzing the change
from baseline adjusted for baseline as a covariate with two
levels of repeated factor.
0
control to the Olestra diet. With Olestra substituting for 1⁄
3
the dietary fat, the expected fat intake was 79 g/day without any
compensatory response. However, due to a partial compensa-
tion, metabolizable fat intake was significantly higher by 5
g/day (p Ͻ 0.002). Carbohydrate intake also was significantly
higher than the calculated intake of 309 g/day (p Ͻ 0.03).
However, there was no significant difference in carbohydrate
intake between the control and Olestra diet periods (Table 3).
Protein intake did not change. Within the control or Olestra diet
periods, there was no significant effect of day on nutrient
intakes (ANOVA, p Ͼ 0.6 for all variables).
In both studies, the baseline body weight was used as a
covariate in body weight change analysis. Statistical analyses
(Proc MIXED) were done on a personal computer using SAS
for Windows, 6.12 (SAS, Inc. Cary, NC). An alpha Ͻ0.05 was
considered significant.
Mean (Ϯ standard error) baseline body weight was 71.8 Ϯ
2
62
VOL. 21, NO. 3

Replacing Fat with Olestra Effect on Body Weight
Table 2. Baseline Characteristics of Participants
Study One
Study Two
Control diet
n ϭ 5 females)
Olestra Diet
(n ϭ 5 females)
Reduced-Fat Diet
(n ϭ 5 females)
(n ϭ 10 males)
(
Age (years)
Weight (kg)
24.5 Ϯ 1.3
25.8 Ϯ 0.9
(24.0–28.0)
72.4 Ϯ 9.3
(52.0–106.9)
27.3 Ϯ 2.5
(22.7–37.0)
38.3 Ϯ 4.8
(27.5–54.5)
28.6 Ϯ 7.7
24.2 Ϯ 1.6
(19.0–28.0)
73.1 Ϯ 6.5
(61.2–97.0)
28.1 Ϯ 2.0
(23.7–34.4)
42.9 Ϯ 3.1
(32.8–52.4)
31.2 Ϯ 5.0
(34.2–42.5)
37.6 Ϯ 1.6
(19.3–49.8)
24.6 Ϯ 1.3
(21.0–28.0)
62.8 Ϯ 1.1
(59.3–65.6)
21.8 Ϯ 0.5
(20.2–23.2)
33.7 Ϯ 2.8
(26.0–40.1)
20.6 Ϯ 1.6
(33.4–42.5)
38.6 Ϯ 1.9
(14.1–22.4)
(21.0–34.0)
71.8 Ϯ 2.0
(62.3–79.6)
2
BMI (kg/m )
23.1 Ϯ 0.6
(20.7–25.5)
Body fat (%)
18.5 Ϯ 2.4
(8.1–31.6)
Fat mass (kg)
(
34.1–45.5)
39.1 Ϯ 2.0
13.7–57.3)
Lean body mass (kg)
(
Mean Ϯ standard error. Ranges are in parentheses.
2
.0 kg (Table 2). Weight reduction was observed during the
Olestra diet, at weeks one and two of the intervention (70.8 Ϯ
.0 kg and 70.1 Ϯ 2.0 kg, respectively; p Ͻ 0.0001). With the
exception of one, all subjects lost weight on the Olestra diet
Fig. 3), and there was a significant effect of study week on
reduced-fat diet. Carbohydrate and protein intakes were signif-
icantly lower for those on the Olestra diet compared to the other
diet groups.
2
The reduction in total energy intake for the Olestra and
reduced-fat diet groups was expected to be similar (13% of
estimated energy for weight maintenance). However, compen-
sation occurred for those on the reduced-fat diet. Daily energy
intake was significantly higher (p Ͻ 0.0001) than expected due
to significantly higher intakes of fat, carbohydrate and protein
than expected if there had been no compensation. Metaboliz-
able fat intake was significantly higher than expected for the
Olestra group (by 10 g/day) throughout the study for both
periods. Similarly, the control group consumed more fat than
expected: 7.5 g/day during the first period (p Ͻ 0.002) and 4.6
g/day during the last period (p Ͻ 0.03).
Mean weight loss (Ϯ standard error) for each diet group is
shown in Fig. 4. All subjects lost weight during the study (p Ͻ
0.0001). From weeks 5 to 10, women in the control group had
no further reduction in weight (p ϭ 0.19). Women in the
Olestra group lost significantly more weight (p Ͻ 0.0001) than
did those on the reduced-fat diet (p ϭ 0.01). The observed
weight loss was due to significant loss of body fat over time
(
body weight (p Ͻ 0.003) with weight loss becoming statisti-
cally significant by the end of the Olestra diet.
Study Two. The subject characteristics are shown in the
right three columns of Table 2. Randomization did not result in
groups that were equally matched. Both lean and obese women
were included in the control and Olestra arms, while only lean
2
women (BMI ϳ20 to 23 kg/m ) were randomized to the re-
duced-fat arm. Although the subjects were randomly assigned,
this is never an assurance that the groups are not different on
some traits as proved to be the case here. Nevertheless, at
baseline, there were no significant differences among groups
for weight or any other variable due to the larger variance with
the small sample size.
The average daily energy and nutrient intakes are shown in
Table 4. Energy intakes, when adjusted for baseline body
weight, for subjects consuming the Olestra and reduced-fat
diets were significantly lower than intakes for those consuming
the control diet. For those consuming the Olestra and reduced-
fat diets, energy intake was less during weeks 5 to 10 than
during the first half of the study. Energy intake did not change
over time for the control subjects. Digestible fat intake differed
among each of the diets and did not change over time. It was
lowest for those on the Olestra diet, followed by that for the
Table 3. Average Macronutrient Intakes for Study One
Control Diet
Olestra Diet
p Value
Energy (kcal)
Fat (g/day)
Carbohydrate (g/day)
Protein (g/day)
2745 Ϯ 146
115.1 Ϯ 7.8
336 Ϯ 18.5
93.5 Ϯ 4.6
2501 Ϯ 86
84.8 Ϯ 2.9
350.6 Ϯ 12.4
95.7 Ϯ 3.1
0.0001
0.0001
NS
NS
Fig. 3. Weight loss for each participant and mean weight loss denoted
Mean Ϯ standard error.
with an asterisk (*) during Study One (difference from control diet).
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION
263

Replacing Fat with Olestra Effect on Body Weight
Table 4. Average Macronutrient Intakes for Study Two
Reduced-Fat
Diet
p Value
Diet
p Value
Diet*Period
Control Diet
Olestra Diet
Energy (kcal)
Period 1
Period 2
p Value for period
Fat (g/day)
Period 1
0.0001
0.0001
0.0002
0.001
NS
0.0001
0.0222
NS
2018 Ϯ 24
2019 Ϯ 22
NS
1659 Ϯ 25
1635 Ϯ 23
0.0195
1821 Ϯ 25
1799 Ϯ 23
0.0253
96.7 Ϯ 1.0
97.6 Ϯ 0.8
NS
64.2 Ϯ 1.1
63.9 Ϯ 1.0
NS
68.5 Ϯ 1.1
68.0 Ϯ 1.0
NS
Period 2
p Value for period
Carbohydrate (g/day)
Period 1
217.8 Ϯ 2.7
217.4 Ϯ 2.0
NS
204.7 Ϯ 3.4
200.6 Ϯ 2.6
0.004
223.7 Ϯ 3.4
221.0 Ϯ 2.7
0.0446
Period 2
p Value for period
Protein (g/day)
Period 1
Period 2
p Value for period
75.7 Ϯ 1.2
75.9 Ϯ 0.9
NS
71.2 Ϯ 1.4
71.1 Ϯ 1.3
NS
75.8 Ϯ 1.4
75.8 Ϯ 1.3
NS
Mean Ϯ standard error. Data adjusted for baseline weight.
NS ϭ non-significant.
Period 1 ϭ Weeks 0 to 4 (all subjects consumed the control diet during week 0).
Period 2 ϭ Weeks 5 to 10.
(
Table 5). From weeks 5 to 10 the Olestra group had a signif-
the day [19,20]. Both of the experiments reported here show
incomplete compensation and suggest that covert replacement
of dietary fat with Olestra results in significant and sustained
reduction in energy intake and weight loss.
icant loss of fat mass (in kg), while the reduced-fat and control
diet groups did not. There were no significant differences in
lean body mass between groups or over time.
Reduction in the digestible fat by 1⁄
with Olestra in the diet
3
of healthy men (approximately 13% of energy) resulted in a
weight loss, which became statistically significant at the end of
the 14-day intervention. A reduction of dietary fat from the
control to the Olestra diet reduced energy intake by nearly 250
kcal/day. If this energy deficit was obtained from adipose tissue
triglyceride stores, 36 g of fat would be metabolized each day
DISCUSSION
Previous short- and intermediate-term studies with Olestra
substitution have shown that energy reduction is made up by
increased food intake [12–14]. Other studies [15–18] did not
find differences in daily energy intake following a replacement
of fat with sucrose polyester in a single meal. In studies lasting
(250 kcal divided by 7 kcal/g for adipose tissue). This would
have produced during the 14 days of intervention a total loss of
about 500 g or 0.5 kg. The mean weight loss was 1.0 kg,
suggesting that some non-triglyceride stores and water were
also lost.
1
4 to 20 days, lean and obese men and women failed to
compensate completely for the reduced fat and energy in the
diet when they consumed Olestra-containing food throughout
The fact that the healthy men in the first experiment did not
eat enough of the free choice foods to make up for the loss of
metabolizable fat energy has two implications. First, it sug-
gests, as have several other studies [21,22], that subjects eat to
maintain the mass of food. Second, it suggests that in the short
term, the calories lost as fat are not detected metabolically. The
small, but significant weight loss in these healthy young men
suggests that perhaps in the short run, gastric distention signals
may be more important than those which arise from the hor-
monal signals generated in the intestinal milieu or from an
energy deficit [22].
The second experiment extended the study of covert fat
replacement to women over a longer period of time (ϳ10
weeks). The weight loss of the women eating the Olestra-
substituted diet during the last six weeks of the study was
significantly greater than the other two groups. As described
Fig. 4. Weight loss (mean Ϯ standard error) during Study Two (dif-
ference from control diet). Between weeks 5 and 10 denoted with an
asterisk (*) weight loss for control is NS and significant for reduced fat
(p Ͻ 0.01) and Olestra groups (p Ͻ 0.0001).
2
64
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Replacing Fat with Olestra Effect on Body Weight
Table 5. Body Composition Measurements (Body Fat, Fat Mass, and Lean Body Mass) for Study Two
Control
Diet
Olestra
Diet
Reduced-Fat
Diet
p Value
Diet
p Value
Diet*Period
Body Fat (%)
Period 1
Period 2
p Value for period
Fat Mass (kg)
Period 1
NS
NS
NS
NS
NS
NS
38.7 Ϯ 4.8
38.0 Ϯ 5.1
NS
41.8 Ϯ 3.1
40.4 Ϯ 2.9
0.048
32.9 Ϯ 2.6
31.1 Ϯ 2.6
0.019
28.5 Ϯ 7.8
28.2 Ϯ 8.5
NS
29.8 Ϯ 5.4
27.5 Ϯ 4.8
0.014
19.6 Ϯ 1.5
18.2 Ϯ 1.4
NS
Period 2
p Value for period
Lean Body Mass (kg)
Period 1
Period 2
p Value for period
38.1 Ϯ 1.9
38.1 Ϯ 2.0
NS
37.1 Ϯ 1.9
36.8 Ϯ 1.9
NS
38.0 Ϯ 1.7
38.5 Ϯ 2.0
NS
Mean Ϯ standard error.
NS ϭ non-significant.
Period 1 ϭ Weeks 0 to 4.
Period 2 ϭ Weeks 5 to 10.
above, if 36 g of fat from fat stores were needed each day to
compensate for the energy deficit, one would anticipate over 10
weeks a loss of approximately 2.5 kg as adipose tissue triglyc-
eride. Subjects in the Olestra group lost 5 kg of body weight by
change in their energy stores, and would then adjust their food
intake accordingly. The study design, i.e., the presence of the
freely available “free choice” foods, allowed them to do so.
However, they did not fully compensate for the energy deficit
when dietary fat was covertly replaced with Olestra.
1
0 weeks, similarly suggesting the loss of additional non-
triglyceride stores and water. Again, free choice foods were not
used to compensate for the lost calories from fat in the Olestra
group. This leads us to conclude that covert replacement of fat
by a fat substitute and the resulting daily withdrawal of small
amounts of fat from body fat stores is not detected by the body.
Conversely, compensation did occur for those consuming the
reduced-fat diet, and their weight loss was less than that of the
women consuming an Olestra diet. The fat substitute masked
detection of daily changes in fat balance. The subjects may
have been compensating for the volume of food, as suggested
by Rolls et al. [23]. The compensation that occurred in Study
Two is consistent with the compensation reported in other
studies above.
It is possible that compensation was seen only for those on
the reduced-fat diet because all subjects in that group were lean,
whereas obese subjects were included in the other two diet
groups. Additionally, we cannot overlook the inclusion of
obese women in the Olestra group and the fact that the greatest
weight loss occurred for this group. Although it might be
tempting to believe these subjects had more incentive to lose
weight, the control group also included obese women and
energy intakes were not restricted. When comparing the weight
loss of the Olestra group to that of the control group, the Olestra
group lost significantly more during the last part of the study
while the control group had no further reduction in weight.
The subjects selected for both studies had been weight
stable for quite some time before the studies started. All sub-
jects were assumed to be “good regulators” of their body
weight. The basic hypothesis was that these subjects would
detect easily the change in energy content of the food, or the
A number of studies have examined diets differing in fat
content on weight loss [10,24–31]. In many, fat content of the
diet was reduced, resulting in an increased carbohydrate con-
tent, so that high fat diets were then compared to high carbo-
hydrate diets. In this respect they differ from the fat substitution
studies where a fat substitute contributes no energy to the food
and can “hide” the lower energy content of the diet in terms of
energy density and hedonic properties. The aforementioned
studies have shown that high carbohydrate diets are associated
with lower energy intake or loss of body weight. This is also
supported by cross sectional studies showing a positive corre-
lation between dietary fat intake and body fatness [32–35]. In
reviews by Bray and Popkin [1] and Lissner and Heitman [2]
cross-cultural comparisons and cross-sectional, prospective and
randomized trials have all provided data consistent with the
idea that higher dietary fat resulted in higher body fat. Lissner
et al. [26] showed that simply reducing the fat content of the
diet resulted in a loss of calories that was uncompensated,
leading to weight loss. In a longer-term study where subjects
had free choice to compensate, Kendall et al. [25] found that
subjects compensated for only 35% of the reduced calories
after 11 weeks. Thus, our studies showing weight loss and
incomplete compensation for the reduction in metabolizable fat
content of the diets are consistent with the findings of other
studies of dietary fat reduction.
In summary, the present report indicates that reduction in
dietary fat content through fat replacement with Olestra results
in significant reduction in energy intake and body weight in
both men and women.
JOURNAL OF THE AMERICAN COLLEGE OF NUTRITION
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Replacing Fat with Olestra Effect on Body Weight
measure dietary restraint, disinhibition and hunger. J Psychosom
Res 29:71–83, 1985.
CONCLUSIONS
9
. Roy HJ, Lovejoy JC, Keenan MJ, Bray GA, Windhauser MM, and
Wilson JK: Substrate oxidation and energy expenditure in athletes
vs. nonathletes consuming isoenergetic high and low fat diets.
Am J Clin Nutr 7:405–411, 1998.
The use of Olestra allowed examination of changes in food
intake when energy density is reduced without altering total
volume of food and physical properties related to dietary fat. A
better understanding of the contributions of dietary fat to obe-
sity will allow health professionals to determine whether re-
ducing dietary fat is a useful strategy in the treatment of
obesity. The diet manipulations in these studies were associated
with a reduction in fat from 40% of total energy to approxi-
mately 30% of energy, both within the range of diet composi-
tion consumed in the US. Our data indicate that a covert energy
1
1
0. Roy HJ, Lovejoy JC: Improvements in matching energy expendi-
ture to food intake in a metabolic chamber utilizing prior measure-
ments of free living activity. In Champagne CM (ed): “21st Na-
tional Nutrient Databank Conference Proceedings.” Baton Rouge:
Pennington Biomedical Research Center Medical Foundation,
1
996.
1. Thomas CD, Peters JC, Reed GW, Abumrad NN, Sun M, Hill JO:
Nutrient balance and energy expenditure during ad libitum feeding
of high-fat and high-carbohydrate diets in humans. Am J Clin Nutr
55:934–942, 1992.
deficit is not detected. The replacement of 1⁄
of the dietary fat
3
with Olestra in periods of up to 10 weeks results in loss of body
weight and fat in both men and women. On average, only a
minor adjustment of food intake was observed during covert fat
substitution with Olestra. Greater compensation, but still in-
complete, occurred with a more traditional reduced-fat diet.
12. Rolls BJ, Pirraglia PA, Jones MB, Peters JC: Effects of Olestra, a
noncaloric fat substitute, on daily energy and fat intakes in lean
men. Am J Clin Nutr 56:84–92, 1992.
1
1
1
1
3. Burley VJ, Blundell JE: Evaluation of the action of a non-
absorbable fat on appetite and energy intake in lean, healthy males.
Int J Obes 15(Suppl):S8, 1991.
4. Birch LL, Johnson SL, Jones MB, Peters JC: Effects of a nonen-
ergy fat substitute on children’s energy and macronutrient intake.
Am J Clin Nutr 58:326–333, 1993.
ACKNOWLEDGMENTS
This work was supported by the USDA (ACSRS 91-34115-
5. Hulshof T, De Graaf C, Westrate JA: The effects of preloads
varying in physical state and fat content on satiety and energy
intake. Appetite 21:273–286, 1993.
6
148). Procter & Gamble Company donated the Olestra.
The authors thank the study volunteers for their time and
effort, without whom these studies would not have been pos-
sible. Additionally, we are indebted to Jana Ihrig, RN, for her
coordination of the studies and to Helena Duplantis, RD, Ca-
milla Ostrowe, Michelle Barkate, RD and the staff of the
Pennington Center Metabolic Kitchen for the food preparation
and the diet analysis. Finally, we are grateful to all the Clinical
Trials staff members for their contributions to the research.
6. Hulshof T, De Graaf C, Weststrate JA: Short-term effects of
high-fat and low-fat/high-SPE croissants on appetite and energy
intake at three deprivation periods. Physiol Behav 57:377–383,
1995.
17. Hulshof T, De Graaf C, Weststrate JA: Short-term satiating effect
of the fat replacer sucrose polyester (SPE) in man. Br J Nutr
74:569–585, 1995.
1
8. Cotton JR, Burley VJ, Blundell JE: Effect on appetite of replacing
natural fat with sucrose polyester in meals or snacks across the
whole day [Abstract]. Int J Obes 17(Suppl):S47, 1993.
1
9. Glueck CJ, Hastings MM, Allen C, Hogg E, Baehler L, Gartside
PS, Phillips D, Jones M, Hollenbach EJ, Braun B, Anastasia JV:
Sucrose polyester and covert caloric dilution. Am J Clin Nutr
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Received August 30, 2001; revision accepted March 25, 2002
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