Does the effect of lifestyle intervention for individuals with diabetes vary by food insecurity status? A preplanned subgroup analysis of the REAL HEALTH randomized clinical trial

Abstract

Introduction: We aimed to test the effectiveness of a lifestyle intervention (LI) for individuals with food insecurity and type 2 diabetes.

Research design and methods: Adults with type 2 diabetes, body mass index ≥25 kg/m2 (or ≥23 kg/m2 if Asian), hemoglobin A1c of 6.5%-11.5% (48-97 mmol/mol) and who were willing to lose 5%-7% bodyweight were enrolled in REAL HEALTH-Diabetes. This practice-based randomized clinical trial compared LI (delivered inperson or by telephone) with medical nutrition therapy (MNT) on weight loss at 6 and 12 months. Two or more affirmative responses on the six-item US Department of Agriculture Food Security Survey Module indicated food insecurity. In this prespecified subgroup analysis, we tested using linear mixed effects models whether the intervention effect varied by food security status.

Results: Of 208 participants, 13% were food insecure. Those with food insecurity were more likely to be racial/ethnic minorities (p<0.001) and have lower education (p<0.001). LI, versus MNT, led to greater weight loss at 6 months (5.1% lost vs 1.1% lost; p<0.0001) and 12 months (4.7% lost vs 2.0% lost; p=0.0005). The intervention effect was similar regardless of food security status (5.1% bodyweight lost vs 1.1% in food secure participants and 5.1% bodyweight lost vs 1.3% in food insecure participants at 6 months; 4.7% bodyweight lost vs 2.1% in food secure participants and 4.5% bodyweight lost vs 0.9% in food insecure participants at 12 months; p for interaction=0.99).

Conclusions: The REAL HEALTH-Diabetes lifestyle intervention led to meaningful weight loss for individuals with food insecurity and type 2 diabetes.

Trial registration number: NCT02320253.

Keywords: diabetes mellitus; type 2; weight reduction programs.

Conflict of interest statement

Competing interests: DJW reports serving on a data monitoring committee for Novo Nordisk. LMD serves on the advisory boards for Omada Health, Jana Care, and WW International. SJC reports employment of a close family member by Johnson & Johnson.

© Author(s) (or their employer(s)) 2020. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.

Figures

Figure 1

Percentage weight loss at 6 and 12 months by intervention arm (LI, lifestyle intervention; MNT, medically nutrition therapy) among those who are food insecure (FI) and food secure (FS). P value for interaction term testing whether the intervention effect varies among subgroups was 0.87 in unadjusted models and 0.99 in models adjusted for age, gender, race/ethnicity, education, primary language, income, and health insurance.

Figure 2

Percentage weight loss at 6 and 12 months by intervention arm (LI, lifestyle intervention; MNT, medical nutrition therapy) by category of annual income (k indicates thousands of dollars). P value for interaction term testing whether the intervention effect varies among subgroups was 0.72 in unadjusted models and 0.69 in models adjusted for age, gender, race/ethnicity, education, primary language, income, and health insurance.