The study of longest duration (14 d) published to date (8)
sought to determine whether fatty acid chain length influenced
EE and substrate oxidation in women. Subjects consumed
a controlled, weight maintenance diet containing 40%
of energy as fat, either in the form of butter and coconut oil
(MCT; 38.9% of fatty acids contained chains with 16 carbons)
or beef tallow. Energy expenditure was measured before
and for 5.5 h after breakfast. Postprandial total EE after MCT
consumption was greater than after LCT consumption on d 7
but not d 14. The authors concluded that the effects of MCT
consumption on EE may be transient.