Diets that are high in trans fats may lead to weight gain
around the middle, even when calories are reduced, a new
U.S. study finds.
Researchers at Wake Forest University School of Medicine
studied monkeys given a diet high in trans fats and low
in calories to see how it affected their body weight.
"Diets rich in trans fat cause a redistribution of
fat tissue into the abdomen and lead to a higher body weight
even when the total dietary calories are controlled,"
Lawrence L. Rudel, a professor of pathology and biochemistry
and head of the Lipid Sciences Research Program, said in
a prepared statement.
The monkeys were studied for six years, and all were male.
Their diets all had the same amount of daily calories and
all had 35 percent of calories from fat. One group was fed
a diet with 8 percent of calories from trans fat, while
the other group received the same percentage from monounsaturated
fats, found in foods like olive oil. The diets were modeled
after a typical Western-style diet, and the amount of trans
fats fed to the monkeys was about the same as an average
person eating a diet high in fried foods.
"We believed they couldn't get obese because we did
not give them enough calories to get fat," explained
Rudel.
Researchers saw the body weight of the monkeys fed the
diet high in trans fats increase by 7.2 percent, while the
monkeys fed monounsaturated fats only had a 1.8 percent
increase in body fat. The extra fat in all of the monkeys
was concentrated in the abdomen, and CT scans showed greater
concentrations of abdominal fat deposits in the trans-fat
diet monkeys -- 30 percent higher than the monounsaturated
diet group.
Results of the study were presented Monday at the American
Diabetes Association's annual scientific sessions, in Washington,
D.C.
"We conclude that in equivalent diets, trans fatty
acid consumption increases weight gain," researcher
Dr. Kylie Kavanagh said in a prepared statement. "In
the world of diabetes, everybody knows that just 5 percent
weight loss makes enormous difference. This little difference
was biologically quite significant."
