- Sheri Colberg, PhD
Losing Weight by Being Active Is Best
Did you know that your body stores fat from excess calories in places other than fat cells? Both your muscles and your liver store extra fat as you gain excess fat weight (1). More fat storage in your muscles may decrease the removal of glucose from your blood, making muscles more resistant to insulin if you don’t exercise regularly (2; 3). Given that your muscles are responsible for the majority of blood glucose uptake in response to insulin, developing insulin-resistant muscles has a substantial impact on your blood glucose. Regular exercisers, paradoxically, can store more fat in their muscles without experiencing insulin resistance, suggesting that the total amount of fat stored there isn’t the critical component but rather how muscles respond to insulin (4).
The greater release of insulin that results from eating excessive amounts of carbohydrate may cause you to gain body fat because carbohydrates are usually converted into and stored as fat when you’re sedentary. If you store fat just in fat cells (particularly in the ones under the skin), you probably will not have as many health problems compared to putting it elsewhere. For example, storing extra fat in your liver may contribute to low-level inflammation, which can lead to the development of insulin resistance, diabetes, heart disease, and other metabolic disorders. Therefore, your liver (and whether or not it stores excess fat) may prove to be a crucial link between weight gain and the development of insulin resistance (1).
An insulin-resistant liver may lead to elevated blood fats and cholesterol levels that contribute to the development of heart disease. You can compound the problem by with dietary choices that contribute to your liver’s insulin resistance, including foods high in refined carbohydrates and highly processed ones. You can lower inflammation and improve your metabolic health with lifestyle changes, including exercising more (5). In fact, being active and eating more fiber naturally in your diet are likely the two most important changes you can make to lower your risk of all metabolic diseases (6).
You don’t have to lose a lot of weight: losing just ten pounds improves your insulin action, lowers inflammation, enhances good cholesterol and lowers the bad, improves metabolic efficiency, and reduces type 2 diabetes risk. Going on a diet to lose weight, however, is not the best long-term solution to managing your body weight or reducing your diabetes risk.
Why? Dieting does not work for most people. It becomes progressively harder to lose weight the longer you stay on a diet (thus making it harder for you to stay motivated to follow it); consequently, many people give up after a while.
A bigger problem is that you are not likely to keep off any weight that you do lose. More than nine out of ten dieters who have successfully lost weight ultimately regain the pounds they struggled to lose. If you go back to eating the same foods after your diet ends that you ate before, you will typically rebound by taking in excessive calories, particularly in the form of extra fat that quickly returns you to your former weight. In fact, most people gain back even more than they lost, regardless of the diet they followed. A greater percentage of the weight you regain is usually body fat, ultimately making your body fat higher than if you had never lost any weight.
While your body’s set point—or what you normally weigh—can change gradually over your lifetime, it remains the same over the relatively short time frame of a diet, unless you make permanent lifestyle changes. If you maintain high levels of daily physical activity while you’re losing weight, though, that will help you prevent gaining it back later on (7). So, if you have to choose between dieting and being more active to lose weight, always choose motion, even if weight loss is slower with exercise alone.
1. Koska J, Stefan N, Permana PA, Weyer C, Sonoda M, Bogardus C, Smith SR, Joanisse DR, Funahashi T, Krakoff J, Bunt JC: Increased fat accumulation in liver may link insulin resistance with subcutaneous abdominal adipocyte enlargement, visceral adiposity, and hypoadiponectinemia in obese individuals. Am J Clin Nutr 2008;87:295-302
2. Coen PM, Dube JJ, Amati F, Stefanovic-Racic M, Ferrell RE, Toledo FG, Goodpaster BH: Insulin resistance is associated with higher intramyocellular triglycerides in type I but not type II myocytes concomitant with higher ceramide content. Diabetes 2010;59:80-88
3. Coen PM, Goodpaster BH: Role of intramyocelluar lipids in human health. Trends Endocrinol Metab 2012;
4. Bergman BC, Butterfield GE, Wolfel EE, Casazza GA, Lopaschuk GD, Brooks GA: Evaluation of exercise and training on muscle lipid metabolism. Am J Physiol 1999;276:E106-117
5. Zoppini G, Targher G, Zamboni C, Venturi C, Cacciatori V, Moghetti P, Muggeo M: Effects of moderate-intensity exercise training on plasma biomarkers of inflammation and endothelial dysfunction in older patients with type 2 diabetes. Nutr Metab Cardiovasc Dis 2006;16:543-549
6. Herder C, Peltonen M, Koenig W, Sutfels K, Lindstrom J, Martin S, Ilanne-Parikka P, Eriksson JG, Aunola S, Keinanen-Kiukaanniemi S, Valle TT, Uusitupa M, Kolb H, Tuomilehto J: Anti-inflammatory effect of lifestyle changes in the Finnish Diabetes Prevention Study. Diabetologia 2009;52:433-442
7. Wang X, Lyles MF, You T, Berry MJ, Rejeski WJ, Nicklas BJ: Weight regain is related to decreases in physical activity during weight loss. Med Sci Sports Exerc 2008;40:1781-1788