Fat Loss vs. Weight Loss: An Important Concept
I remember how disappointed many participants in one of my clinical studies dealing with weight loss became because their bathroom scale readings had not changed dramatically over time. I was disappointed too. My research team and I had been working for some months on this double-blinded, placebo-controlled study involving overweight African American women to determine if niacin-bound chromium (NBC) could influence weight loss. All the subjects were placed in a modest exercise program with instructions concerning reducing caloric intake. Half of the group was given NBC and the other half, a placebo. Even though the study was blinded, I had naturally hoped to see half of the women lose significant weight to suggest that the NBC was effective.
While there were no dramatic changes in the scale readings, some of the ladies stated “— but my dress size is getting smaller.” This did not ring a bell until the study was completed and unblinded. Fortunately, we had not only measured scale weight, but fat loss as well. The test and placebo groups both lost similar, modest amounts of weight, approximately 3 pounds over two months. But the group consuming the NBC lost almost all of the weight as fat. The placebo group lost only 40% as fat — 60% of what was lost was muscle. Only then did I understand the reason for the dress size changes that occurred in the NBC group. The women on the chromium lost all their weight as fat, which resulted in more inches lost than when dense muscle is lost, as it was in the placebo group. Three pounds of weight loss over two months is ‘so-so,” but three pound of fat-loss makes a difference in how clothes fit and what you see when you look in the mirror.
This study taught me the concept that overweight individuals should lose fat, not muscle. How many huge, peer-reviewed studies have examined weight loss and not considered the percentage of fat loss and muscle loss? A colleague of mine, Dr. Gil Kaats, has performed numerous ‘weight loss” studies on thousands of individuals that included examining body proportions. In examining all his data, roughly 20% of subjects lost scale weight (good), but a greater portion of their weight loss was muscle, not fat (bad). The lesson here is that weight loss by the scale can be deceiving. We simply do not want to lose significant weight via muscle loss. Simple caloric restriction without the addition of the dietary supplement as carried out by the African American women in our study caused significant weight loss via muscle depletion. Rather than scale weight, belt, pants and dress-size may be more important to estimate fat loss.
Why is retaining muscle mass so important? Simply stated, the answer is that muscle burns calories thus preventing the lost fat from returning (“yo yo effect”). In addition, retaining muscle helps prevent the development of sarcopenia (significant loss of muscle mass), especially prevalent in aging. Sarcopenia is as important a consideration as osteoporosis in the elderly. I’ll talk about that in a future column.
