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When a Doctor’s “Prescription” to Lose Weight May Do More Harm than Good

Sep 19, 2006

Have you ever told a patient to eat better, lose weight and get their A1c down? Sheri Colberg, Ph.D., FACSM has some interesting information on how your "Prescription" to Lose Weight May Do More Harm than Good, and why the scale is not the only measure of success.

SheriWhen a Doctor’s "Prescription"to Lose Weight May Do
More Harm than Good

By Sheri Colberg, Ph.D., FACSM


When you found out about your diabetes from your doctor, he or she probably told you to lose weight, eat better, take your medications, and exercise more. Maybe the recommendations were not laid out in exactly that order, but I would bet that weight loss was one of the top recommendations. However, since long-term dieting has such a high failure rate, a blanket prescription for heavier people to lose weight has the potential to harm you more than help you. Although some weight loss may improve your insulin sensitivity, losing large amounts of weight will likely be unnecessary–not to mention unrealistic–to achieve your blood glucose goal. Thus–and I can’t stress this enough–your success at controlling your sugars should not be pinned on significant weight loss or some unattainable target body weight.

Consider the case of one woman diagnosed with diabetes in her early 40s. At the time she weighed 270 pounds, which categorized her as “morbidly obese,” and her glycated hemoglobin, which should have been 7 percent or lower to be well controlled, was almost double that at 14 percent. Over the next few months, she started eating better and exercising more, and her overall diabetes control vastly improved: her glycated hemoglobin levels dropped to 8 percent and then to under 6 percent—reflective of an average blood glucose level within normal, nondiabetic limits—over that period of time. When she saw her doctor again, he expressed disappointment about her progress solely because she had not lost any weight. In fact, he told her in no uncertain terms that she obviously didn’t care about her health since weight loss should be her main focus and she was failing to lose any.

Not only was this physician’s fixation on weight loss misguided (since he ignored the vast improvements in her diabetes management accomplished without weight loss), it was also emotionally counterproductive for the woman, failing to give her the encouragement and praise she deserved for so effectively managing her blood glucose levels on her own. As an exercise physiologist, I can tell you that embarking on a new program of regular exercise can actually make you gain weight rather than lose it in the short term.

Why exercise makes your body weight change more slowly

About the only thing that exercise can’t do is make your body weight go down faster than dieting alone—if you have decided to go on a diet. This phenomenon is not inherently bad, and it deserves a fuller explanation. When you diet, the weight that you lose is a combination of body fat, muscle mass, and water weight. By exercising, you actually help retain and even gain some muscle mass, which is good since muscle is sensitive to the effects of insulin and is a good place to store your extra glucose. The downside of retaining or gaining muscle–if it really can be considered a downside–is that muscle is denser than body fat and, thus, it weighs more. Consequently, you can lose fat while retaining or gaining muscle with exercise, and your weight on the scales may change very little (or even rise slightly at first), even though your body composition is undeniably changing for the better.

Use exercise to stop gaining more weight

An added benefit of exercise is that even if it doesn’t help you lose all of the weight you want to, it can still prevent you from gaining weight while you positively modify your body composition (that is, you lose fat while gaining muscle). Many adults are still trying to lose or maintain their body weight by dieting, yet very few are also using exercise. In my opinion, dieters must be avoiding exercise either out of ignorance or out of an unwillingness to believe how important it is to weight control.
Even though weight loss may be slower when exercise is part of the regimen, making lifestyle changes is a much better method of both accomplishing better glucose control and losing weight than using supplemental insulin to improve overall diabetes control. When people with type 2 diabetes implement lifestyle changes (exercise and dietary modifications) alone, their diabetes control improves similarly to those who either have just begun using insulin or who implement the same lifestyle changes along with using insulin. However, if you are using supplemental insulin, you’re likely to end up gaining as much or more weight over the course of a year than you’ll lose by making lifestyle changes alone. Be forewarned, however, that you will lose almost all of the glycemic and body weight improvements if you fail to maintain your lifestyle changes.

In two weeks, I will share more tips and ideas from my latest book, The 7 Step Diabetes Fitness Plan: Living Well and Being Fit with Diabetes, No Matter Your Weight (2006). Information about all of my books, my many articles, my research, and more is available on my web site: www.SheriColberg.com.

Tip for the day: Don’t let your bathroom scale get you down. When you start exercising more, your weight may not go down very quickly, and it may even go up for a while, but such changes are far from meaning that you aren’t making any headway. Pay more attention to your waist and hip measurements and to how loose your clothes are getting than to your weight on a regular scale.

See more features from Sheri Colberg, Ph.D., FACSM