Overweight adults ( body mass index @-@ @ kg/m ( @ ) ; age @-@ y , @ % non-white , and @ % men ) were randomized to a low-fat , low-glycemic index diet : vegan ( n = @ ) , vegetarian ( n = @ ) , pesco-vegetarian ( n = @ ) , semi-vegetarian ( n = @ ) , or omnivorous ( n = @ ) .