In overweight or obese patients with diabetes, a lifestyle intervention increased weight loss at 8 years

Receiving an intensive lifestyle intervention (ILI) rather than traditional diabetes support and education (DSE) increased weight loss in about 5,000 middle-aged adults with type 2 diabetes. The ILI group received weekly group or individual counseling sessions for the first 6 months, followed by monthly meetings for the remaining 90 months of the study. The sessions encouraged them to reduce calorie consumption and increase activity. On average, the ILI patients lost 4.7% of their body weight, compared to 2.1% in the DSE group.

The study was published in Obesity in January 2014. The following commentary by Eric C. Westman, MD, MHS, was published in the ACP Journal Club section of the June 17 Annals of Internal Medicine.

This substudy of the Look AHEAD trial, which was stopped early due to a lack of benefit in cardiac events, showed 4.7% weight loss over 8 years with an “intensive” lifestyle intervention. One might wonder why we should even bother with lifestyle interventions?

Although the Look AHEAD trial was intended to assess the effect of weight loss, it couldn't because of the lack of sustained weight loss in the ILI group. That group lost 8.5% body weight after the first year, but subsequent regain reduced weight loss to 4.7% at study end. At baseline, average BMI was 36 kg/m². Is it plausible to expect that modest weight loss would be sufficient to reduce cardiac events?

The authors acknowledged that a different dietary composition might have had a different effect. The ILI did not have an intensive nutritional component. Two large RCTs have shown that a similar reduced-fat, restricted-calorie, nutritional intervention had little to no mortality benefit for participants with or without diabetes. However, 3 RCTs comparing dietary interventions showed a reduction in cardiac endpoints or carotid intimal thickness. A glycemic index–based carbohydrate restriction approach makes more pathophysiologic sense as treatment for diabetes than a low-fat, calorie-restricted diet.

The Look AHEAD trial did not examine the stronger weight loss approaches used by obesity specialists to achieve substantial, sustained weight loss (e.g., individualized lifestyle counselling, medication, or meal replacements); the effects of these alternate strategies on hard outcomes still need to be tested.