  In short, the Okinawans circa 1950 ate sweet potatoes for  of the of food that they consumed, which constituted 69\% of their total calories.
<meaning-changed>   In short, the Okinawans circa 1950 ate sweet potatoes for  of the of food that they consumed, which constituted 69\% of their total calories.
 In short, the Okinawans circa 1950 ate sweet potatoes for 849 grams of the 1262 grams of the of food that they consumed, which constituted 69\% of their total calories.