TABLE 1

Effect of overfeeding (ad libitum) on body weight and metabolic parameters

Control
Pair-fed
Ad libitum
3 Days7 Days3 Days7 Days3 Days7 Days
n 6 6 8 12810 
Body weight (g)298 ± 8.0301 ± 7.0304 ± 6.0289 ± 6.0332 ± 14322 ± 6.0*
Δ Body weight (g)−6.0 ± 4.0−8.0 ± 4.0−13 ± 4.0−7.0 ± 3.025 ± 5.0*26 ± 4.0*
Calorie intake (kcal/d)56 ± 4.057 ± 5.051 ± 2.051 ± 2.0112 ± 8.0*105 ± 7.0*
Plasma glucose (mmol/l)6.9 ± 0.26.7 ± 0.36.8 ± 0.26.9 ± 0.18.1 ± 0.1*7.1 ± 0.2
Plasma FFA (mmol/l)0.9 ± 0.10.8 ± 0.21.0 ± 0.20.9 ± 0.10.9 ± 0.21.0 ± 0.2
Plasma insulin (ng/ml)1.0 ± 0.20.9 ± 0.20.9 ± 0.20.8 ± 0.31.7 ± 0.4*1.9 ± 0.3*
Plasma leptin (ng/ml)0.8 ± 0.30.7 ± 0.31.2 ± 0.20.9 ± 0.12.8 ± 0.5*1.8 ± 0.3*
Basal GP (mg · kg–1 · min–1)11.1 ± 0.210.2 ± 0.38.7 ± 0.310.0 ± 0.414.1 ± 0.4*12.1 ± 0.7
  • Biochemical parameters are the means ± SE of three basal measurements from each rat. Caloric intake is the mean ± SE of the cumulative intake during the 3 or 7 days preceeding the in vivo study. Food was withdrawn 5 h before plasma sampling. FFA, free fatty acid; GP, rate of endogenous glucose production.

  • *

    * P < 0.01 vs. control and pair-fed.