Vegan Diets and Dietary Energy Density: A Secondary Analysis of a Randomized Clinical Trial
Results
Of 3115 people screened by telephone, 244 adults with overweight met participation criteria and were randomly assigned to the vegan (n = 122) or control (n = 122) groups. The analysis included 223 (91.0%) completers. Total food weight did not change significantly in either group (Table). Energy intake decreased in both groups, more in the vegan group (effect size, −357.1 kcal/d; 95% CI, −521.9 to −192.3 kcal/d; P < .001) (Table). Energy density did not change in the control group but decreased by 30% in the vegan group (effect size, −0.28 kcal/g/d; 95% CI, −0.38 to −0.19 kcal/g/d; P < .001; Table and Figure).
Reductions in dietary energy density were associated with greater weight loss (r = 0.28; 95% CI, 0.15 to 0.39; P < .001), remaining significant after adjustment for energy intake (r = 0.21; 95% CI, 0.08 to 0.34; P = .002). A 1-kg weight loss corresponded to a 0.29-unit decrease in energy density (P < .001), or 0.36 units after adjustment (P = .002).