Authors
Ludwig DS. Majzoub JA. Al-Zahrani A. Dallal GE. Blanco I. Roberts SB.
Institution
Division of Endocrinology, Department of Medicine, Children's
Hospital,Boston, 300 Longwood Ave, Boston, MA 02115, USA.
Title
High glycemic index
foods, overeating, and obesity.
Source
Pediatrics. 103(3):E26, 1999 Mar.
Abstract
OBJECTIVE: The prevalence of obesity has increased dramatically in recent
years. However, the role of dietary composition in body weight regulation
remains unclear. The purpose of this work was to investigate the acute
effects of dietary glycemic index (GI) on
energy metabolism and voluntary food intake in obese subjects. METHODS:
Twelve obese teenage boys were evaluated on three separate occasions using a
crossover study protocol. During each evaluation, subjects consumed identical
test meals at breakfast and lunch that had a low, medium, or
high GI. The high- and medium-GI meals were
designed to have similar macronutrient composition, fiber content, and
palatability, and all meals for each subject had equal energy content. After
breakfast, plasma and serum concentrations of metabolic fuels and hormones
were measured. Ad libitum food intake was determined in the 5-hour period
after lunch. RESULTS: Voluntary energy intake after the
high-GI meal (5.8 megajoule [mJ]) was 53% greater than after
the medium-GI meal (3.8 mJ), and 81% greater than after the low-GI meal (3.2
mJ). In addition, compared with the low-GI meal, the high-GI
meal resulted in higher serum insulin levels, lower plasma
glucagon levels, lower postabsorptive plasma glucose and serum fatty acids
levels, and elevation in plasma epinephrine. The area under the
glycemic response curve for each test meal accounted for 53%
of the variance in food intake within subjects. CONCLUSIONS: The rapid
absorption of glucose after consumption of high-GI meals
induces a sequence of hormonal and metabolic changes that promote excessive
food intake in obese subjects. Additional studies are needed to examine the
relationship between dietary GI and long-term body weight regulation.