A scalable, virtual weight management program tailored for adults with type 2 diabetes: effects on glycemic control

**Background:** Diabetes is a costly and debilitating disease, with $245 billion in total costs in 2012. The ADA Standards of Care emphasize weight management for T2D. The LookAHEAD trial showed that intensive lifestyle intervention produced 7.9% greater weight loss and 0.5% greater HbA1c reduction versus usual care at 1 year. However, clinic-based programs have limited reach and high cost. Community-based programs like WeightWatchers (WW) are more accessible. A prior randomized trial of a modified WW program for T2D showed improved HbA1c and weight loss versus standard care. This study tested a new WW program tailored for T2D and delivered virtually.

**Methods:** This single-arm, three-site trial (Pennington Biomedical Research Center, University of Florida, Virginia Commonwealth University) enrolled 136 participants between April–June 2021. Inclusion criteria: T2D diagnosis, age 18–70 y, HbA1c 7–11%, BMI 27–50 kg/m², stable medication >3 months. Mean baseline characteristics: age 56.8±0.8 y, BMI 36.9±0.5 kg/m², 80.2% female, 62.2% non-Hispanic white, HbA1c 8.0±0.09%, weight 101.10±1.47 kg, DDS total 2.35±0.08. The 24-week intervention included weekly virtual workshops (30–60 min), WW App with SmartPoints® system targeting ~750 kcal/day deficit, weekly check-ins, and private online community. For T2D, higher-carbohydrate foods (fruit, yogurt, whole grains) were not ZeroPoint foods to encourage tracking. Primary outcome: change in HbA1c at 24 weeks. Secondary outcomes: body weight, waist circumference, DDS, IWQOL-L, hunger (VAS). Analyses used intent-to-treat with general linear mixed effects models adjusted for sex. The study had 90% power to detect a 0.5±1.7% HbA1c reduction (n=120).

**Key Results:** At week 24, HbA1c decreased by 0.75±0.11% (p<0.0001). Among those with baseline HbA1c ≥8% (n=52, mean 8.95±0.12%), HbA1c decreased by 1.35±0.16% (p≤0.0001); among those <8% (n=84, mean 7.41±0.10%), HbA1c decreased by 0.38±0.13% (p=0.0026). Body weight decreased by 5.10±0.46 kg (5.74±0.50%) at week 24 (p<0.0001). Weight loss ≥3% was achieved by 60% of participants, ≥5% by 43%, and ≥10% by 15%. Waist circumference decreased by 5.91±0.53 cm (p<0.0001). Diastolic blood pressure decreased by 2.8±1.0 mmHg (p=0.0076); systolic BP decreased by 3.1±1.7 mmHg (p=0.0630, not significant). DDS total score decreased by 0.33±0.10 units (p=0.0007), with significant reductions in Emotional Burden (−0.33±0.12, p=0.0062) and Regimen-Related Distress (−0.62±0.13, p<0.0001). IWQOL-L total score increased (improved) by 9±1 units (p<0.0001), with all subscales significantly improved. Hunger decreased by 14±2 units (p<0.0001).

**Clinical Implications:** The >0.5% HbA1c reduction, >5% weight loss, and reduction in DDS from moderate to low distress are all clinically meaningful. The HbA1c reduction compares favorably to in-person community-based approaches and an earlier WW version with individual sessions. The virtual, scalable format has potential to mitigate access and affordability barriers for adults with T2D. Limitations include the single-arm design (no control group) and potential regression to the mean, though the authors note that nearly 6% weight loss is unlikely to occur spontaneously. Results await replication in a randomized controlled trial.