EVEN a low-calorie diet can lead to potentially dangerous burger bellies, if it is rich in trans fats.
Trans fats, commonly found in fast foods, can significantly increase the risk of heart disease. Kylie Kavanagh at Wake Forest University Baptist Medical Center in Winston-Salem, North Carolina, and her colleagues decided to test the effects of this "killer fat" on body weight.
They fed one group of African green monkeys a diet with 8 per cent of its calories from trans fats, equivalent to one fast-food burger-and-fries meal a day. The other group ate the same amount of total fat - 35 per cent of total calories - but without the trans fat. Both groups ate the same total calories, just enough for subsistence.
After six years on the diet, trans fat-fed monkeys gained an extra 7.2 per cent of their body weight, compared to just 1.8 per cent in the control monkeys. They also had 30 per cent more abdominal fat, which increases the risk of diabetes and heart disease.
"We were shocked. Despite all our enormous efforts to make sure they didn't gain weight, they still did," says Kavanagh, who presented the findings at the American Diabetes Association meeting in Washington DC this week - days after American fast-food giant Wendy's announced it was eliminating trans fats from its products.
From issue 2556 of New Scientist magazine, 17 June 2006, page 21