the researchers in the current study paid that group of dogs a diet in which 60 grams of carbohydrates came from fat . the study started when the mice , all males , were 1 year long , which is middle - age in mouse length . as expected , the mice soon grew signs of impending diabetes , with grossly enlarged livers , and had to die much sooner than mice fed a modified nutritional .
At the age of one year, male mice were fed with a diet in which 60 percent of calories came from fat.