Re: FYI

[Tivers@aol.com]

n a message dated 7/26/00 11:28:03 AM Pacific Daylight Time, 
suendavid@worldnet.att.net writes:

<< Interesting.  Custelow, Ferrante and Taylor's work in 1993 said just the
 opposite---that metabolic effect of dietary fats takes time (~ 11 weeks) to
 acclimitize.  I'll have to go re-read the article and look at the protocol
 again.
 
 Susan G >>


Ok, here's another one to peruse while you're reading:


Authors SR Smith, L deJonge, JJ Zachwieja, H Roy, T Nguyen, J Rood, M 
Windhauser, J Volaufova, GA Bray
Title   Concurrent physical activity increases fat oxidation during the shift 
to a high-fat diet
Full source American Journal of Clinical Nutrition, 2000, Vol 72, Iss 1, pp 
131-138

Background: It takes several days to adapt to a high-fat diet. In an earlier 
study, we observed a large degree of interindividual variation in the 
capacity to adapt to a high-fat diet. We hypothesized that concurrent 
physical activity would accelerate fat oxidation during an isoenergetic 
high-fat diet. Objective: The objective of this study was to determine the 
effect of increased physical activity on the ability of young healthy men to 
increase fat oxidation during the shift to a high-fat diet. Design: Six young 
healthy men participated in a randomized, single-blind crossover study. The 
volunteers consumed a diet contributing 37% of energy as fat, 14% as protein, 
and 49% as carbohydrate for 4 d. Energy expenditure and macronutrient balance 
were then measured in a respiration chamber as the energy content of the 
isoenergetic diet was changed to 50% fat, 14% protein, and 36% carbohydrate. 
Treadmill walking, as the physical activity, was used to increase total daily 
energy expenditure to 1.8 times the resting metabolic rate during 1 of 2 
stays in the metabolic chamber. Total daily energy expenditure was maintained 
at 1.4 times the resting metabolic rate for the other stay. Results: Energy 
balance was not significantly different between the 2 conditions. The 24-h 
respiratory quotient decreased more rapidly and to a greater extent under 
conditions of increased energy expenditure. Further, there was a decrease in 
the interindividual variability in the response of the respiratory quotient 
to a high-fat diet with increased energy expenditure (physical activity). 
Cumulative carbohydrate and protein balances were greater under conditions of 
increased physical activity. Conversely, cumulative fat balance was greater 
under sedentary conditions. Conclusion: Concurrent physical activity 
increases fat oxidation during the shift to a high-fat diet.