Predictors of sustained reduction in energy and fat intake in the Diabetes Prevention Program Outcomes Study intensive lifestyle intervention.

BACKGROUND

Few lifestyle intervention studies examine long-term sustainability of dietary changes.

OBJECTIVE

To describe sustainability of dietary changes over 9 years in the Diabetes Prevention Program and its outcomes study, the Diabetes Prevention Program Outcomes Study, among participants receiving the intensive lifestyle intervention.

DESIGN

One thousand seventy-nine participants were enrolled in the intensive lifestyle intervention arm of the Diabetes Prevention Program; 910 continued participation in the Diabetes Prevention Program Outcomes Study. Fat and energy intake derived from food frequency questionnaires at baseline and post-randomization Years 1 and 9 were examined. Parsimonious models determined whether baseline characteristics and intensive lifestyle intervention session participation predicted sustainability.

RESULTS

Self-reported energy intake was reduced from a median of 1,876 kcal/day (interquartile range [IQR]=1,452 to 2,549 kcal/day) at baseline to 1,520 kcal/day (IQR=1,192 to 1,986 kcal/day) at Year 1, and 1,560 kcal/day (IQR=1,223 to 2,026 kcal/day) at Year 9. Dietary fat was reduced from a median of 70.4 g (IQR=49.3 to 102.5 g) to 45 g (IQR=32.2 to 63.8 g) at Year 1 and increased to 61.0 g (IQR=44.6 to 82.7 g) at Year 9. Percent energy from fat was reduced from a median of 34.4% (IQR=29.6% to 38.5%) to 27.1% (IQR=23.1% to 31.5%) at Year 1 but increased to 35.3% (IQR=29.7% to 40.2%) at Year 9. Lower baseline energy intake and Year 1 dietary reduction predicted lower energy and fat gram intake at Year 9. Higher leisure physical activity predicted lower fat gram intake but not energy intake.

CONCLUSIONS

Intensive lifestyle intervention can result in reductions in total energy intake for up to 9 years. Initial success in achieving reductions in fat and energy intake and success in attaining activity goals appear to predict long-term success at maintaining changes.