Somewhere we’ve gone wrong in communicating the strong and indisputable scientific evidence that exercise plays an important role in weight management. As a consequence many people with obesity are confused and frustrated with the less than expected weight loss achieved when they begin to exercise. The media-hype has contributed to this confusion. Sensational headlines can relay an inaccurate message that exercise is not helpful (or healthful). To make matters worse some scientists even disagree on the role of exercise. In their controversial editorial published in the British Journal of Sports Medicine (Br J Sports Med 2015;49:15 968-969), the authors conclude that “It is time to wind back the harms caused by the junk food industry’s public relations machinery. Let us bust the myth of physical inactivity and obesity. You cannot outrun a bad diet”. The editorial and sensational media coverage has set back progress in the practice of weight management.
Make no mistake, there is no myth involving the important role of exercise in weight management. The partial truth is that on average exercise alone does not promote much weight loss. This is sometimes surprising even to scientists. Expending a large number of calories during exercise can be difficult for individuals with obesity and low fitness levels. Some compensate for exercise by becoming more sedentary and/or eating more during the remainder of the day following exercise. The bottom line is that a reduction in calories consumed is needed for most individuals to lose a meaningful amount of weight. Suffice it to mention that any diet that reduces calories, is adequate in nutrients, doesn’t require a dramatic exclusion of fat, protein or carbohydrate, and can be adhered to will probably work just fine.
So, why is exercise important in weight management? The most important reason for anyone to exercise is to reduce the risk of chronic diseases and to improve mental and physical health. Obesity is associated with an increased the risk for chronic diseases, reduced quality of life, and reduced life expectancy. Exercise has a favorable impact on all of these and more. In addition, exercise reduces the risk of weight gain and avoiding further weight gain and mitigating comorbidities such as diabetes and cardiovascular disease should be the first goal of any sound weight management program. Importantly, exercise also reduces the risk of gaining weight after weight loss.
Weight loss is a short-term strategy that involves expending more calories than consumed. A goal of 5-10% weight loss within 6-12 months is achievable for most and is a level associated with improvements in many of the health problems associated with obesity. More ambitious goals are possible but also more challenging to achieve. Engaging the help and advice of healthcare professionals should contribute to individual success.
Weight management is a lifestyle, one that involves an ongoing use of behavioral change strategies (e.g., daily weighing) that are helpful in maintaining weight. Those who are most successful at maintaining weight loss over time rely on a number of behavioral strategies such as reported by participants in the National Weight Control Registry (www. nwcr.ws/research), the largest prospective investigation of long-term successful weight loss maintenance. The registry is composed of individuals who have lost 30 to 300 pounds and maintained their weight loss for 1 to 66 years. Among a multitude of positive health behaviors common to these individuals, most exercise daily for an average of an hour per day and consume a low fat, low calorie diet. Over half of these individuals lost weight with the help of some type of program. Many commercial weight loss programs such as Jenny Craig and Weight Watchers have been shown to be helpful. The most prudent approach to weight loss and weight management, particularly for those with health problems accompanying excess weight, should involve consultation with a qualified healthcare provider with training and experience in weight management.
More effective communication on the science of exercise and weight management is needed. Several elements should be considered. Scientists need to be precise and objective when discussing their work. The differences between weight loss and weight management is more than semantic in nature. Healthcare professionals need to be clear with short-term goals for weight loss and longer-term goals for weight maintenance. The goals should be reasonable and easily distinguished. The importance of healthy eating and exercise as part of a lifestyle approach should be emphasized. Of course, the media also has a responsibility in maintaining the delicate balance between writing eye catching sciences stories and accurately delineating what is known and not known. Finally, the consumer needs to be critical of all sources of information particularly when the sources is other than healthcare providers with the qualifications, training and experience in weight management.