Regular exercise among women with type 2 diabetes may not only reduce waist size, but may also reduce the amount of visceral fat surrounding organs in the abdomen — the type of fat known to be associated with insulin resistance, a study shows.
“Exercise needs to be part of the prescription” for controlling type 2 diabetes, study author Dr. Jill A. Kanaley of Syracuse University in upstate New York told. “You want to reduce that visceral fat because you want all the health benefits that come with it,” she said.
Previous studies have shown that the accumulation of fat around the organs results in higher levels of free fatty acids and consequent disturbances in glycemic control, since free fatty acids are known to influence the release of insulin from the pancreas. Although researchers have found that weight loss, or exercise without weight loss, can help reduce abdominal fat and improve one’s sensitivity to insulin, such research did not include men and women with type 2 diabetes, whose bodies may respond differently to diet and exercise.
In the current study, Kanaley and her team divided 33 postmenopausal women with type 2 diabetes into one of three study groups. One group followed a high monounsaturated fat diet, the second group did not diet, but participated in a regular walking program with occasional bicycling, and the third group both dieted and exercised.
By the end of the 14-week study period, women who dieted and those who dieted and exercised experienced similar weight loss — about 10 pounds — and similar reductions in total body fat. Those who exercised without dieting experienced little weight loss — less than five pounds — and a much smaller reduction in body fat, Kanaley and her team report in this month’s issue of the Journal of Clinical Endocrinology & Metabolism.
Women in all three groups experienced changes in the distribution of fat around their abdomen, however, reducing their waist circumference by about 4 centimeters, the report indicates.
Women who dieted, with or without exercise, reduced their total abdominal fat and subcutaneous fat — the fat that sits just under the skin, but not their visceral fat, while those who exercised, with or without dieting, were able to reduce the amount of fat tucked in around their organs. Those who dieted and exercised decreased their total abdominal fat as well as the fat under the skin and around the organs.
In fact, the researchers note, exercise reduced fat in all three areas, even when the exercisers did not experience any significant weight loss.
“The beauty of it is they didn’t lose much weight at all and they got the benefits,” Kanaley said.
Women in all three groups experienced an approximate 44 percent increase in insulin sensitivity — they became more efficient processors of blood sugar, the researchers note.
Altogether, the findings show that although modest weight loss, either through diet alone or diet and exercise leads to improvements in total abdominal fat, subcutaneous fat, and glycemic status, exercise is needed to reduce visceral fat, the researchers conclude.
“As important as the diet is, the exercise is also important,” Kanaley said, adding that women with type 2 diabetes should “get out and exercise.”