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/m2 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 χ2 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.