Effekt av högfettkost på kroppssammansättning, lipidmetabolism & insulinkänslighet

[King Grub]

Dietary fat composition can interfere in the development of obesity due to the specific roles of some fatty acids that have different metabolic activities, which can alter both fat oxidation and deposition rates, resulting in changes in body weight and/or composition. High-fat diets in general are associated with hyperphagia, but the type of dietary fat seems to be more important since saturated fats are linked to a positive fat balance and omental adipose tissue accumulation when compared to other types of fat, while polyunsaturated fats, omega-3 and omega-6, seem to increase energy expenditure and decrease energy intake by specific mechanisms involving hormone-sensitive lipase, activation of peroxisome proliferator-activated receptor α (PPARα) and others. Saturated fat intake can also impair insulin sensitivity compared to omega-3 fat, which has the opposite effect due to alterations in cell membranes. Obesity is also associated with impaired mitochondrial function. Fat excess favors the production of malonyl-CoA, which reduces GLUT4 efficiency. The tricarboxylic acid cycle and beta-oxidation are temporarily uncoupled, forming metabolite byproducts that augment reactive oxygen species production. Exercise can restore mitochondrial function and insulin sensitivity, which may be crucial for a better prognosis in treating or preventing obesity.

Braz J Med Biol Res. 2011 Aug 26. Effect of high-fat diets on body composition, lipid metabolism and insulin sensitivity, and the role of exercise on these parameters.

http://www.scielo.br/scielo.php?scri...rm=iso&tlng=en

[Eddie Vedder]

Väldigt säkra uttalanden om omega-3 och insulinkänslighet där. Så vitt jag vet råder delade meningar där. Och flera observationsstudier visar ju på samband med högre incidens av diabetes typ 2 bland de som äter mer omega-3. Inga kausala samband men ändå något som väcker en del funderingar. Det är ju liksom en hälsosam vana så den vanliga typen av felkällor i människor som "gör allt rätt" blir ju svårare att ta till där.

Och resultaten är ju inte heller konsekventa:

http://www.ajcn.org/content/early/20...13334.abstract

http://www.ajcn.org/content/93/1/143.short

http://www.ajcn.org/content/early/20...0.009357.short