Corinne Metzger, M.S.
Maybe you have cut back on calories to fit into your favorite pair of jeans. On the other side of the spectrum, doctors encourage people to lose weight to lower the risk of chronic diseases. And beyond that, athletes watch their calories in the hopes of being leaner, lighter, or faster for their sport. All these are good, right? Cutting back on calories may help prevent some diseases, may help build confidence for bikini season, and help athletes perform better. So nothing bad can come from it, right? Wrong. Few people realize that restricting calories can harm the foundational structure of your body – your bones.
Unlike the brick walls of a building, our bones adapt to what we do and what we don’t do. Our physical activities and diet play a large role in the health of our bones. Not only are bones affected by what we eat, but they also are greatly influenced by how much we eat. Bones are dependent on energy availability – the amount of calories in our diets available for our metabolic needs beyond those expended during physical activity. Caloric restriction has detrimental effects on bone. Reduced energy available to the body leads to a loss of bone mass and bone strength. Even when the ideal weight is achieved, bone loss can continue to occur after returning to a normal calorie diet (Hinton et al.). Even with a high amount of exercise, which is generally considered good for bone, athletes who engage in caloric restriction can lose bone mass. Whether they are reducing calories by choice in an effort to improve performance or solely due to the intensity of their training, athletes who do not consume sufficient calories have a greater risk of stress fractures in the short term and have increased risk of premature osteoporosis and elevated fracture risk later in life.
So how do we keep the foundation of our bodies strong? The simplest solution is to eat well, eat enough, and get moving (walking, jogging, and weight lifting). Healthy eating—enough calories and the right source of calories is critical to maintaining bone health. Some research has shown that, in addition to the amount of energy in our diet, dietary composition can also have an important impact on preserving bone during a time of caloric restriction. During a weight loss program, researchers at Rutgers University found that a diet high in protein lessened some of the bone loss seen with a weight loss diet in postmenopausal women (Sukumar et al.). The complete picture of the role of protein in the diet is still unclear, but there is hope that dietary adjustments during a period of caloric restriction could help preserve bones.
Before “bikini season” comes around this year, think about the foundation of your body and the rest of your life. Eat the right amount of nutritious food and get moving. Your bones will thank you.
- Hinton PS, LeCheminant JD, Smith BK, Rector S, Donnelly JE. Weight loss-induced alterations in serum markers of bone turnover persist during weight maintenance in obese men and women. Journal of the American College of Nutrition, 2009;28(5):565-573. http://www.ncbi.nlm.nih.gov/pubmed/20439552
- Sukumar D, Ambia-Sobhan H, Zurfluh R, Schlussel Y, Stahl TJ, Gordon CL, Shapses SA. Areal and volumetric bone mineral density and geometry at two levels of protein intake during caloric restriction: a randomized, controlled trial. Journal of Bone and Mineral Research, 26(6), 2011. http://onlinelibrary.wiley.com/doi/10.1002/jbmr.318/pdf