Leptin and insulin responses to a four-day energy-deficient diet in men with different weight history

OBJECTIVE: To assess the leptin responses to a 4-day energy-restricted diet in men with different weight history; high retrospective weight gain was expected to be associated with a small decline in leptin. DESIGN: Changes in fasting leptin and insulin were measured during a 4-day controlled intervention, in which men with high retrospective weight gain and men who had stable weight consumed 35% of their estimated energy needs. SUBJECTS: A total of 44 healthy men (age: 31-52y, BMI: 22.7-39.8 kg/m(2)) were recruited from a cohort study: 22 men who had gained weight (weight change >1 kg/y) and 22 men whose weight had remained stable (weight change +/-0.3kg/y) between the first (1987-1991) and the second measurement (1993-1997) of the cohort study. The intervention study was carried out in 2001. RESULTS: After intervention changes in fasting leptin levels were similar for both groups of retrospective weight gain: -2.2 mulU/ml (95% Cl: -2.8; -1.7) and -2.4 mulU/ml (95% Cl: -3.2; -1.7) respectively (P = 0.69). Proportional changes in fasting leptin levels were different: -43.3% (95% Cl: -47.8; -38.4) in the participants whose weight had remained stable (n-22) and -35.2% (95% Cl: -42.4; -27.1) in those who had gained weight (n=22)(P