Most of the focus of diabetes management and prevention is on losing weight. However, I think that the emphasis on weight loss alone is misguided for several reasons, and we need to find a way to focus on beneficial changes in body composition instead (i.e., lower body fat, muscle mass gains)….
Second, emphasizing weight loss alone without requiring concomitant physical activity is likely to cause a loss not only of fat weight, but also of muscle mass — leaving you with less muscle and a lower metabolic rate when you’re done. If you regain the weight (like 90-95% of people eventually do), then you will end up with a higher percent of body fat than if you had never lost any weight in the first place, along with higher blood sugar levels when you do eat carbs. The muscle mass that can potentially gain from doing resistance work with weights or bands may be of greater importance for diabetes control and prevention and pre-diabetes reversal, particularly if you’re currently sedentary. In one study on people with type 2 diabetes, 4-6 weeks of moderate (40-50 percent of maximal) resistance training improved their insulin sensitivity by 48 percent, even without causing any measurable changes in their body fat (2). Similarly, men newly diagnosed with type 2 diabetes undertaking 16 weeks of progressive resistance training just twice a week gained muscle mass, lost body fat, and greatly enhanced their insulin action — all while eating 15 percent more daily calories (3).
Third, studies have clearly shown that it is not general weight loss that is required to manage or prevent diabetes, but rather specific loss of deep abdominal (visceral) fat that can interfere with normal metabolic function. Free fatty acids released from visceral fat directly enter your liver and have a detrimental effect on how responsive the liver is to insulin; therefore, losing visceral fat (as opposed to the below-the-skin variety) may benefit you the most. Both aerobic and resistance training result in loss of more visceral fat compared with dieting, and a combination of both types of training may afford even greater improvements in insulin action and more significant decreases in visceral fat than aerobic training alone, with increased muscle mass as a side benefit (4). Dieting by itself is more likely to reduce subcutaneous and total abdominal fat, but not necessarily the visceral type. Moreover, exercisers maintain their muscle mass while the dieters-only lose some muscle in the process. You should definitely include regular exercise to lose the worst type of fat and to keep the muscle that you have, especially when you go on a diet.
One final thought: the bigger problem is not weight loss itself (which most people can accomplish when trying to), but prevention of weight regain after weight loss. While your diet has an impact, a better focus is on physical activity. For example, in the Diabetes Prevention Program research, while the strong association between weight loss and diabetes risk reduction might make you think that weight loss is more important, the results from the rest of those analyses favor of physical activity. Among the 495 participants not meeting the study’s weight loss goals (that is, a 5-7 percent loss of body weight) after one year, everyone who met the physical activity goal (30 minutes or more of walking five days a week) had a 44 percent lower chance of developing type 2 diabetes even without weight loss, showing the absolute importance of exercise (5). Even though eating fewer calories and being physically active were the main factors that predicted the weight loss in those who met those goals, maintaining regular physical activity was most important behavior for keeping the weight off afterwards. In fact, most of the individuals who lost weight but failed to continue to exercise regained all of it eventually.
In conclusion, it’s always better to keep checking your waist and other measurements (or just how your clothes fit) than to set your goals solely based on changes in your scale weight, which is not necessarily reflective of positive changes in your body fat and muscle mass. Focus on making better dietary choices and exercising moderately. Pick healthier foods with a lower calorie density — such as an apple instead of an apple-filled muffin — and if you do reward yourself for working out with food, check the calorie content first to make sure you don’t eat more calories than you expended. Simply moving more throughout the day (including standing up more often and longer), not just doing your gym workouts, will also help give you the best body composition with less sweating required.
- Colberg SR, Sigal RJ, Fernhall B, Regensteiner JG, Blissmer BJ, Rubin RR, Chasan-Taber L, Albright AL, Braun B; American College of Sports Medicine; American Diabetes Association. Exercise and type 2 diabetes: the American College of Sports Medicine and the American Diabetes Association: joint position statement. Diabetes Care. 2010;33(12):e147-67.
- Ishii T, Yamakita T, Sato T, et al. Resistance training improves insulin sensitivity in NIDDM subjects without altering maximal oxygen uptake. Diabetes Care. 1998; 21: 1353–5.
- Ibaňez J, Izquierdo M, Arguelles I, et al. Twice-weekly progressive resistance training decreases abdominal fat and improves insulin sensitivity in older men with type 2 diabetes. Diabetes Care. 2005; 28: 662–7.
- Giannopoulou I, Ploutz-Snyder LL, Carhart R, et al. Exercise is required for visceral fat loss in postmenopausal women with type 2 diabetes. J Clin Endocrinol Metab. 2005; 90: 1511–8.
- Hamman RF, Wing RR, Edelstein SL, et al. Effect of weight loss with lifestyle inter-vention on risk of diabetes. Diabetes Care. 2006;29(9):2102-7.
Sign up for the Diabetes "Fit Brain, Fit Body!" fitness/lifestyle programs or for 5 free Healthy Living Reports at www.lifelongexercise.com, and access more articles and information at www.shericolberg.com. If you need tips for getting safely started on an exercise program, check out The 7 Step Diabetes Fitness Plan. For people with any type of diabetes who are already more active, consult the Diabetic Athlete’s Handbook.