Background: Portion size is an important determinant of energy intake. To our knowledge, no randomized controlled trial has evaluated the efficacy of portion control tools to induce weight loss. In patients with type 2 diabetes mellitus, weight reduction improves glycemic control.
Methods: We randomly assigned 130 obese patients with type 2 diabetes mellitus (including 55 patients taking insulin) to the daily use of a commercially available portion control plate for 6 months (intervention group) vs to usual care in the form of dietary teaching (usual care control group).
Results: Follow-up was 93.8%. Patients in the intervention group lost significantly more weight than control subjects (mean+/-SD, 1.8%+/-3.9% vs 0.1%+/-3.0%, P=.006). Compared with controls, more patients in the intervention group required a decrease in their diabetes medications at 6 months (26.2% vs 10.8%, P=.04).
Conclusions: Compared with usual care, the portion control tool studied was effective in inducing weight loss. The portion control plate also enabled patients with diabetes mellitus to decrease their hypoglycemic medications without sacrificing glycemic control.
Trial registration: clinicaltrials.gov Identifier: NCT00254124.