Modest lifestyle intervention and glucose tolerance in obese African Americans

Objective: Previous studies have demonstrated the benefit of short-term die ts on glucose tolerance in obese individuals. The purpose of this study was to evaluate the effectiveness of modest lifestyle changes in maintaining i mprovements in glucose tolerance induced by short-term energy restriction i n obese African Americans with impaired glucose tolerance or type 2 diabete s mellitus. Research Methods and Procedures: An intervention group (n = 45; 47 +/- 1 ye ar [mean +/- SE]), 105 +/- 4 kg; body mass index: 39 +/- 1 kg/m(2)) receive d an energy-restricted diet (943 +/- 26 kcal/d) for 1 week, followed by a l ifestyle program of reduced dietary fat (-125 kcal/d) and increased physica l activity (+125 kcal/d) for 1 year. Body weight and plasma concentrations of glucose, insulin, and C-peptide during an oral glucose tolerance test we re measured at baseline, 1-week, and 4-month intervals. A control group (n = 24; 48 +/- 1 year; 110 +/- 5 kg; body mass index: 41 +/- 2 kg/m2) underwe nt these measurements at 4-month intervals. Results: No-changes in weight or glucose tolerance were observed in the con trol group. The intervention group had significant (p < 0.05) improvements in body weight and glucose tolerance in response to the 1-week diet, which persisted for 4 months (p < 0.001 vs. control for change in weight). A tota l of 19 subjects (42%) continued the intervention program for 1 year, with sustained improvements (weight: -4.6 +/- 1.0 kg; p < 0.001 vs. control; ora l glucose tolerance test glucose area: -103 +/- 44 mM . min; p < 0.05 vs. c ontrol). Discussion: A modest lifestyle program facilitates weight loss and enables improvements in glucose tolerance to be maintained in obese individuals wit h abnormal glucose tolerance. However, attrition was high, despite the mild nature of the program.