Weight loss program may improve HbA1c more than typical diabetes nutrition counseling, study finds

The study, funded by a grant from Weight Watchers International, randomly assigned adults with type 2 diabetes to the weight loss program plus diabetes education or diabetes-specific nutritional counseling plus written follow-up.

Among adults with type 2 diabetes, participation in a Weight Watchers (WW) program supplemented with diabetes education was associated with greater improvements in HbA1c and weight than standard diabetes nutritional counseling, according to a recent randomized clinical trial.

At 16 U.S. sites, researchers compared the adapted program (which included weekly in-person WW meetings, standard online tools, and coordinated telephone and email consultations with a certified diabetes educator) with standard care, defined as 1 in-person session of type 2 diabetes nutritional counseling by a registered dietitian plus written follow-up. The study was funded by a grant from Weight Watchers International. Results were published online on Nov. 2 by Obesity.

Using change in HbA1c at 12 months as the primary outcome, researchers randomized 279 participants to receive free access to the program and 284 to receive standard care. Participants were monitored at follow-up visits at 3, 6, 9, and 12 months.

Although both groups lost weight during the trial, the WW group lost more than the control group at each follow-up (P <0.001 for all comparisons). Modeled 12-month percent weight loss in the WW group was 4.0% (95% CI, 3.1% to 4.0%), compared to 1.9% (95% CI, 1.3% to 2.0%) in the standard care group. At 12 months, the proportion of those losing at least 5% of their body weight was 34.3% in the WW group and 18.1% in the control group (P<0.001).

Over the trial, the HbA1c of WW participants decreased by 0.32% (P<0.001), whereas HbA1c increased by 0.16% among control subjects (P=0.020). More WW participants than controls achieved HbA1c below 7.0% at 12 months (23.8% vs. 13.6%; P=0.004). In addition, more WW participants than controls reduced their diabetes medications over the trial (26% vs. 12%; P<0.001).

The study authors noted limitations to the study, such as how its design did not allow them to ascertain the individual effects of the WW program and supplemental counseling. However, post hoc analyses showed significantly greater glycemic improvement in participants who received 2 or more counseling sessions than in those who received fewer than 2 (P=0.036). The authors also noted the potential impacts of overall attrition and the unblinded nature of the trial. They added that these results may not be generalizable to individuals who are not receiving ongoing diabetes care.