ABSTRACT
Background Type 2 diabetes mellitus is increasing- ly common, primarily because of increases in the prev- alence of a sedentary lifestyle and obesity. Whether type 2 diabetes can be prevented by interventions that affect the lifestyles of subjects at high risk for the dis- ease is not known.
Methods We randomly assigned 522 middle-aged, overweight subjects (172 men and 350 women; mean age, 55 years; mean body-mass index [weight in kilo- grams divided by the square of the height in meters],
31) with impaired glucose tolerance to either the in- tervention group or the control group. Each subject in the intervention group received individualized coun- seling aimed at reducing weight, total intake of fat, and intake of saturated fat and increasing intake of fi- ber and physical activity. An oral glucose-tolerance test was performed annually; the diagnosis of diabe- tes was confirmed by a second test. The mean dura- tion of follow-up was 3.2 years.
Results The mean (±SD) amount of weight lost be- tween base line and the end of year 1 was 4.2±5.1 kg in the intervention group and 0.8±3.7 kg in the control group; the net loss by the end of year 2 was 3.5±5.5 kg in the intervention group and 0.8±4.4 kg in the control group (P