‘Super Size’ diet increases insulin resistance
Scientists study effects of a month-long fast food binge
Too much fast food could put people on a fast track to diabetes, a new study suggests.
Just one month on a fast food diet was enough to alter the ability of fat cells to respond to insulin, researchers from Linköping University in Sweden reported online April 30 in Molecular Medicine. The inability to respond properly to insulin, called insulin resistance, is a hallmark of type 2 diabetes.
Cell biologist Peter Strålfors of Linköping University got the idea to put people on a fast food diet from the 2004 documentary Super Size Me, in which a man eats a steady diet of McDonald’s food and grows heavier and increasingly ill. Strålfors recruited 18 lean young people to go on a fast food binge. At the beginning of the experiment, the volunteers averaged a trim body mass index of 22.4. Body mass index, or BMI, is calculated from a person’s weight and height and indicates the degree of body fat, in most cases. A BMI between 18.5 and 24.9 is considered normal.
To follow a high-calorie diet, volunteers ate two fast food meals a day for a month. They also restricted physical activity to 5,000 steps a day — half the recommend amount of daily exercise. Before the experiment began, the researchers extracted fat from under the skin of the volunteers’ bellies. Or tried to — the volunteers were so lean that researchers were able to get enough fat for analysis from only six people.