We always hear that weight loss is necessary for the prevention and treatment of heart disease and diabetes. But is this widely accepted belief really accurate?
While carrying around an excess of weight does not cause, but can contribute to heart disease and diabetes, weight loss as the standard treatment for these problems may be overrated. The assumption has always been that decreasing body fat will automatically result in improved glucose tolerance, blood pressure and cholesterol (HDL, LDL and total) levels.
Based on this assumption, the best way to evaluate the impact of body fat on metabolic profile is to remove body fat without making any other changes in diet, exercise or lifestyle. A group of researchers set out to prove that removal of body fat alone through liposuction would result in improved cardiovascular and metabolic health.
Fifteen obese women, eight of whom had normal glucose levels and seven of whom had type 2 diabetes underwent abdominal liposuction. The nondiabetic women lost an average of 20 pounds of fat and the diabetic group lost an average of 23 pounds through the liposuction procedure. After the procedure, the women were directed to maintain their normal eating, activity and lifestyle routines. For 10 – 12 weeks they were contacted weekly and reminded to do things as they normally would do.
Although 20 – 23 pounds of abdominal fat was removed from these women, their metabolic profile did not improve. Surprisingly, blood pressure, cholesterol levels and fasting glucose and insulin levels were the same after the removal of this significant amount of body fat.
The researchers were confounded by these results since it is literally assumed that weight loss automatically improves the indicators of cardiovascular disease and insulin sensitivity.
Perhaps what is also surprising is that we don’t hear about the large body of data showing that weight loss is not the critical determinant for reducing the risk or symptoms of diabetes or heart disease. There have been plenty of studies published in the most prominent medical journals, such as the Journal of the American Medical Association (JAMA) and the New England Journal of Medicine (NEJM), as well as others, showing that the risks for and progression of cardiovascular disease and diabetes can be decreased through lifestyle changes separate from weight loss.
It is unfortunate that this information is not more widely publicized because making lifestyle changes independent of whether weight is lost is likely more achievable than is weight loss through dieting. However, not only is the medical community entrenched in the long held belief that weight loss is essential for health, our cultural expectations of what body type (e.g., thin) is acceptable fully support that belief.
What the research shows is that moderate exercise, defined as 30 – 60 minutes three times per week, improves insulin sensitivity and glucose control and significantly lowers the risk of cardiovascular disease compared to those who are sedentary. This is true even when weight does not change as the result of exercise.
Trying to lose weight can be highly discouraging and the lack of success with it may lead people to believe that exercise is not working or worth it if weight loss is not the result. Contrary to this is plenty of data supporting exercise as an effective intervention on its own. We certainly have more control over our choice to exercise than we have control over weight loss.
So, include moderate exercise in your overall health care routine and focus on improving your health status rather than the number on the scale!
(For more information on exercise and how to make it part of your routine, see the archived article “I Hate Exercise” by Dr. Lees).