Food Groups and Risk of Overweight, Obesity, and Weight Gain: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

This meta-analysis summarizes the evidence of a prospective association between the intake of foods [whole grains, refined grains, vegetables, fruit, nuts, legumes, eggs, dairy, fish, red meat, processed meat, and sugar-sweetened beverages (SSBs)] and risk of general overweight/obesity, abdominal obesity, and weight gain. PubMed and Web of Science were searched for prospective observational studies until August 2018. Summary RRs and 95% CIs were estimated from 43 reports for the highest compared with the lowest intake categories, as well as for linear and nonlinear relations focusing on each outcome separately: overweight/obesity, abdominal obesity, and weight gain. The quality of evidence was evaluated with use of the NutriGrade tool. In the dose-response meta-analysis, inverse associations were found for whole-grain (RR(overweight/obesity): 0.93; 95% CI: 0.89, 0.96), fruit (RR(overweight/obesity): 0.93; 95% CI: 0.86, 1.00; RR(weight gain): 0.91; 95% CI: 0.86, 0.97), nut (RR(abdominal obesity): 0.42; 95% CI: 0.31, 0.57), legume (RR(overweight/obesity): 0.88; 95% CI: 0.84, 0.93), and fish (RR(abdominal obesity): 0.83; 95% CI: 0.71, 0.97) consumption and positive associations were found for refined grains (RR(overweight/obesity): 1.05; 95% CI: 1.00, 1.10), red meat (RR(abdominal obesity): 1.10; 95% CI: 1.04, 1.16; RR(weight gain): 1.14; 95% CI: 1.03, 1.26), and SSBs (RR(overweight/obesity): 1.05; 95% CI: 1.00, 1.11; RR(abdominal obesity): 1.12; 95% CI: 1.04, 1.20). The dose-response meta-analytical findings provided very low to low quality of evidence that certain food groups have an impact on different measurements of adiposity risk. To improve the quality of evidence, better-designed observational studies, inclusion of intervention trials, and use of novel statistical methods (e.g., substitution analyses or network meta-analyses) are needed.