Objective: Changing dietary and physical activity habits has the potential to postpone or prevent the development of type 2 diabetes. However, it needs to be assessed whether moderate interventions, in agreement with current guidelines for the general population, are effective. We evaluated the impact of a 2-year combined diet and physical activity intervention program on glucose tolerance in Dutch subjects at increased risk for developing diabetes.
Research Methods and Procedures: Subjects with glucose intolerance were randomly assigned to either the lifestyle intervention group (INT) or control group (CON). The INT received regular dietary advice and was stimulated to increase their physical activity. The CON received a brief leaflet about healthy diet and increased physical activity. Primary outcome measure was the change in glucose tolerance.
Results: In total, 88 subjects completed 2 years of intervention (40 subjects in the INT, 48 subjects in the CON, mean BMI 29.4 kg/m2). Subjects in the INT reduced their body weight, waist circumference, and (saturated) fat intake and improved their aerobic capacity. Two-hour plasma glucose concentration declined from 8.7 to 8.0 mM in the INT and rose from 8.6 to 9.4 mM in the CON (p < 0.01). Subjects adherent to both the diet and exercise intervention showed the largest reduction in 2-hour glucose levels.
Discussion: Our results showed that a lifestyle intervention program according to general recommendations improves glucose tolerance, even in a less obese and more physical active population. Furthermore, our results underscore the importance of combining diet and physical activity to improve glucose tolerance and insulin resistance.