A multicenter randomized controlled trial of a nutrition intervention program in a multiethnic adult population in the corporate setting reduces depression and anxiety and improves quality of life: the GEICO study.

ABSTRACT

PURPOSE: To determine whether a plant-based nutrition program in a multicenter, corporate setting improves depression, anxiety, and productivity. DESIGN: A quasi-experimental study examined the impact of diet on emotional well-being and productivity. SETTING: The study was conducted in 10 corporate sites of a major U.S. insurance company. SUBJECTS: There were 292 participants (79.8% women, 20.2% men), with body mass index ≥25 kg/m(2) and/or previous diagnosis of type 2 diabetes. INTERVENTION Either weekly instruction in following a vegan diet or no instruction was given for 18 weeks. MEASURES: Depression and anxiety were measured using the Short Form-36 questionnaire. Work productivity was measured using the Work Productivity and Activity Impairment questionnaire. ANALYSIS: Baseline characteristics were examined by t-test for continuous variables and χ(2) test for categorical variables. Analysis of covariance models were adjusted for baseline covariates. Paired t-tests were used to determine within-group changes and t-tests for between-group differences. RESULTS: In an intention-to-treat analysis, improvements in impairment because of health (p < .001), overall work impairment because of health (p = .02), non-work-related activity impairment because of health (p < .001), depression (p = .02), anxiety (p = .04), fatigue (p < .001), emotional well-being (p = .01), daily functioning because of physical health (p = .01), and general health (p = 0.02) in the intervention group were significantly greater than in the control group. Results were similar for study completers. CONCLUSION: A dietary intervention improves depression, anxiety, and productivity in a multicenter, corporate setting.