A Shift Toward a Plant-Centered Diet From Young to Middle Adulthood and Subsequent Risk of Type 2 Diabetes and Weight Gain: The Coronary Artery Risk Development in Young Adults (CARDIA) Study

OBJECTIVE To examine the associations between change in plant-centered diet quality and type 2 diabetes risk and change in body size. RESEARCH DESIGN AND METHODS A prospective study conducted in the U.S. enrolled adults ages 18-30 years in 1985-1986 (examination year [Y0]) and followed them through 2015-2016. We analyzed the associations between change in plant-centered diet quality over 20 years (Y0-Y20) and diabetes (Y20-30;n= 2,534) and change (Y0-Y20 and Y20-30) in BMI, waist circumference (WC), and weight (n> 2,434). Plant-centered diet quality was measured using the A Priori Diet Quality Score (APDQS); a higher score favors nutritionally rich plant foods. Cox regression models were used to assess diabetes risk, and linear regression models were used to examine change in body size. RESULTS During a mean follow-up of 9.3 (+/- 1.7) years, 206 case subjects with incident diabetes were observed. In multivariable analysis, participants with the largest increase in APDQS over 20 years had a 48% (95% CI 0.31-0.85;P-trend< 0.001) lower risk of diabetes over the subsequent 10 years compared with participants whose score remained stable. Each 1-SD increment in APDQS over 20 years was associated with lower gains in BMI (-0.39 kg/m(2); SE 0.14;P= 0.004), WC (-0.90 cm; SE 0.27;P< 0.001) and weight (-1.14 kg; SE 0.33;P< 0.001) during the same period, but not with subsequent changes. CONCLUSIONS Young adults who increased plant-centered diet quality had a lower diabetes risk and gained less weight by middle adulthood.