Effects of metformin on energy intake and satiety in obese children

Abstract

Aims: To investigate the effects of metformin on appetite and energy intake in obese children with hyperinsulinaemia.

Methods: We conducted a 6-month randomized, double-blind, placebo-controlled trial to evaluate the effects of metformin 1000 mg twice daily on body weight and energy balance in 100 obese children with hyperinsulinaemia aged 6-12 years. The children ate ad libitum from standardized food arrays on two separate occasions before and after 6 months of study medication. The first test meal was consumed after an overnight fast. The second was preceded by a pre-meal load. For each test meal, energy intake was recorded, and the children completed scales of hunger, fullness and desire to eat.

Results: Data from the meal studies at baseline and after treatment with study medication were available for 84 children (metformin-treated, n = 45; placebo-treated, n = 39). Compared with placebo, metformin treatment elicited significant reductions from baseline in adjusted mean ± standard error of the mean energy intake after the pre-meal load (metformin: -104.7 ± 83.8 kcal vs. placebo: +144.2 ± 96.9 kcal; p = 0.034) independently of changes in body composition. Metformin also significantly decreased ratings of hunger (-1.5 ± 5.6 vs. +18.6 ± 6.3; p = 0.013) and increased ratings of fullness (+10.1 ± 6.2 vs. -12.8 ± 7.0; p = 0.01) after the pre-meal load.

Conclusions: These data suggest that decreased perceived hunger resulting in diminished food intake are among the mechanisms by which metformin treatment reduces body weight in overweight children with hyperinsulinaemia.

Trial registration: ClinicalTrials.gov NCT00005669.

Keywords: child; energy intake; insulin resistance; metformin; obesity.

Figure 1

Change in energy intake from baseline to 6 months of treatment adjusted for changes in body composition for Food Array I (Fig 1A, after an overnight fast) and Food Array II (Fig 1B, after a pre-load shake-like beverage). Mean ± SEM of the change in food intake is shown.

Figure 2

Change in hunger (A) and fullness (B) ratings after the pre-meal milk-shake-like beverage. Mean ± SEM of the change in hunger and fullness ratings from baseline to 6 months of treatment. *P < 0.02