Fifty-five healthy adults [ 30 males and 25 females ; mean ( SD ) age 27.7 ( 7.1 ) years ; mean ( SD ) body mass index 24 ( 3.8 ) kg m ( -2 ) ] were randomly assigned to a 2-day food trial ( high-fat meal or high-carbohydrate meal ) or a 2-day drink trial ( water or high electrolyte drink ) .