EFFECT OF DIET COMPOSITION ON LEPTIN CONCENTRATION IN LEAN SUBJECTS

The recently discovered leptin is thought to be a satiety signal regul ating food intake, In mice, it has been shown that on a high-fat diet leptin concentration increases, but the increase was explained by incr eased fat mass, It is yet unknown whether leptin is influenced by othe r nutritional factors. Here, leptin levels were measured in human volu nteers on a high-fat diet, while maintaining energy balance, Twelve he althy, non-obese males and females (age, 26 +/- 2 years; 21.4 +/- 0.5 body mass index, habitual fat intake, 29 +/- 1 energy % [en%]) consume d a high-fat diet (60 en% fat) for 7 days (days 1 to 7). Subjects were in energy balance (range, -0.15 to +0.23 MJ/d) as measured in a respi ration chamber on days 1 to 3 and 7. Fasting baseline plasma leptin co ncentrations correlated with body fat percentage (R(2) = .64, P < .005 ). On average, no changes in leptin concentration on the high-fat diet were observed. However, on an individual basis, changes in leptin con centrations in response to the high-fat diet correlated with changes i n insulin concentrations, In conclusion, in the case of energy balance , short-term changes in diet composition have no effect on fasting lep tin concentration in lean subjects. Copyright (C) 1997 by W.B. Saunder s Company.