Diet quality is inversely associated with obesity in Chinese adults with type 2 diabetes

BACKGROUND: Diet quality has been linked to obesity, but this relationship remains unclear in individuals with type 2 diabetes (T2D). The aim of this study is to examine the association between diet quality and obesity in Chinese adults with T2D. METHODS: Between April and November 2016, a total of 211 Chinese T2D adults who underwent assessment of diabetes-related treatment goals and metabolic control were recruited into two groups based on their body mass index (BMI): obese group (BMI ≥30 kg/m(2)) and non-obese group (BMI = 18.5–24.9 kg/m(2)). Diet quality indices including Alternate Healthy Eating Index-2010 (AHEI-2010), Diet Quality Index-International (DQI-I), and Dietary Approach to Stop Hypertension (DASH) score, were derived from a validated food frequency questionnaire. RESULTS: Obese T2D patients had significantly lower AHEI-2010 (P < 0.001), DQI-I (P < 0.001), and DASH total scores (P = 0.044) than their non-obese counterparts, independent of age and sex. They also had higher total energy (P < 0.001), protein percentage of energy (P = 0.023), and meat, poultry and organ meat (P < 0.001), but lower vegetable (P = 0.014) intakes. Our multivariate logistic regression analyses demonstrated that the AHEI-2010, but not DQI-I and DASH, total score had an inverse association with obesity, independent of sociodemographics, anti-diabetic medication use, physical activity level and total energy intake (odds ratio [OR] per standard deviation (1-SD) increase: 0.95, 95% confidence interval [CI]: 0.91–0.99, P = 0.020). This association remained significant after further adjustment for glycemic control. Inverse associations were also found between obesity and multivariate-adjusted component scores, including AHEI-2010 red/processed meat (OR per 1-SD: 0.71, 95% CI: 0.51–0.99, P = 0.044), DQI-I variety (OR per 1-SD: 0.63, 95% CI: 0.46–0.86, P = 0.004), and DASH red/processed meat (OR per 1-SD: 0.57, 95% CI: 0.38–0.84, P = 0.005). CONCLUSIONS: Better diet quality, as characterized by higher AHEI-2010 scores, was associated with lower odds of obesity in Chinese adults with T2D. Dietary patterns reflecting high consumption of plant-based foods and low consumption of animal-based, high-fat, and processed foods may be imperative to optimize nutritional guidance for obesity management in this population. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s12937-018-0374-6) contains supplementary material, which is available to authorized users.