the researchers in the current study fed two sample of mice a diet in who 60 percent of grams originated from food . the diet started when the rats , all males , were 1 year old , which is low - age in mouse longevity . as expected , the boys soon developed signs of possible diabetes , with grossly enlarged livers , and seemed to die much sooner than chickens fed a standard diet .
at the height of 1 year , male animals were fed with a foods in which 60 points of calories came from fat .