Effect of 3 modified fats and a conventional fat on appetite, energy intake, energy expenditure, and substrate oxidation in healthy men.
BACKGROUND
Different dietary fats are metabolized differently in humans and may influence energy expenditure, substrate oxidation, appetite regulation, and body weight regulation.


OBJECTIVE
We examined the short-term effects of 4 triacylglycerols (test fats) on subjective appetite, ad libitum energy intake, meal-induced thermogenesis, and postprandial substrate oxidation.


METHODS
Eleven healthy, normal-weight men (mean age: 25.1 +/- 0.5 y) consumed 4 different test fats [conventional fat (rapeseed oil) and 3 modified fats (lipase-structured fat, chemically structured fat, and physically mixed fat)] in a randomized, double-blind, crossover design.


RESULTS
No significant differences in appetite sensations or ad libitum energy intakes were observed between the 4 test fats. Overall, the 4 fats exerted different effects on energy expenditure (meal effect: P < 0.01) and substrate oxidation (interaction between meal and time: P < 0.05). In post hoc tests, the 3 modified fats resulted in significantly higher postprandial energy expenditure and fat oxidation than did the conventional fat (P < 0.008, Bonferroni adjusted); no significant differences were observed between the 3 modified fats.


CONCLUSIONS
Structured fats do not change short-term postprandial appetite sensations or ad libitum energy intakes but do result in higher postprandial energy expenditure and fat oxidation than do conventional fats and hence promote negative energy and fat balance. In humans, a physically mixed fat (trioctanoate + rapeseed oil) is metabolized as quickly as are structured fats. The position of medium-chain fatty acids on the glycerol backbone of triacylglycerols does not seem to affect energy expenditure or appetite.
Bendixen
Hanne
H
Research Department of Human Nutrition, the Centre for Advanced Food Studies, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark. hb@kvl.dk
Flint
Anne
A
Raben
Anne
A
Høy
Carl-Erik
CE
Mu
Huiling
H
Xu
Xuebing
X
Bartels
Else Marie
EM
Astrup
Arne
A
D000328:Adult; D000704:Analysis of Variance; D001066:Appetite / Q000187:drug effects*; D002153:Calorimetry, Indirect; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000378:metabolism / Q000494:pharmacology*; D004311:Double-Blind Method; D002149:Energy Intake; D004734:Energy Metabolism / Q000187:drug effects*; D006801:Humans; D008297:Male; D010084:Oxidation-Reduction; D011795:Surveys and Questionnaires
D004041:Dietary Fats