Diet effects on fatty acid metabolism in lean and obese humans

The primary role of adipose tissue is to serve as a temporary storage site for energy in the form of nonesterified fatty acids. The regulation of adipose tissue lipolysis, which allows the appropriate delivery of fatty acids to meet the lipid fuel needs of lean tissue, is affected by the amount and the location of fat, as well as by the diet. Excessive accumulation of triacylglycerol fatty acids (obesity) is associated with an increased risk of insulin resistance, diabetes, hyperlipidemia, and hypertension. Some of these abnormalities may be related to dysregulation of fatty acid metabolism. Body fat distribution exerts a major influence on endogenous nonesterified fatty acid metabolism, which may in turn mediate some of the metabolic abnormalities associated with upper-body obesity. The effects of diet on fatty acid metabolism can be dramatic and are not the same in upper-body and lower-body obesity. Different obesity phenotypes may respond differently to low-fat, high-complex-carbohydrate diets, and the response is further modified depending on whether the diet is isoenergetic or restricted in energy.