Methods: Participants (N=84) were randomly assigned to a low-fat vegan diet supplemented with soybeans (n=42) or an omnivorous control group (n=42) for 12 weeks. Three-day diet records were analyzed using the Nutrition Data System for Research software; the NOVA classification was used to assess processed food consumption. A repeated measures ANOVA was used for statistical analyses. Results: Consumption of unprocessed or minimally processed animal foods decreased in the vegan group, compared with the control group; effect size: −106 g/d (95% CI: −169 to −42); P=0.002. The reduction in consumption of unprocessed or minimally processed animal foods was associated with weight loss (r=+0.45; P<0.001) and a reduction in severe hot flashes (r=+0.31; P=0.01). Similarly, consumption of ultra-processed animal foods decreased in the vegan group by 60 g/d (95% CI: −105 to −15); P=0.004, with no significant change in the control group; effect size: −65 g/d (95% CI: −115 to −16); P=0.01. The reduction in consumption of ultra-processed animal foods was associated with weight loss (r=+0.43; P<0.001). Consumption of ultra-processed plant-based foods changed only minimally and nonsignificantly and was not associated with changes in weight or hot flash frequency. Conclusions: These findings suggest that, in the context of a soybean-supplemented vegan diet, replacing the consumption of both unprocessed or minimally processed and ultra-processed animal foods with plant foods (regardless of the level of processing), was associated with significant weight loss and a reduction in severe hot flashes....