Overweight and obesity result from a combination of genetic, metabolic, and lifestyle factors. The good news is that you can manage your weight successfully by managing the lifestyle factors that affect it. Changes in our weight depend on the balance of the energy we take inâ€” in the form of calories in foodâ€”and the energy we burnâ€”by our metabolism and any additional physical activity we do. If we eat more calories than we burn, we gain weight. Itâ€™s really just that simple. Thereâ€™s no magic. To control our weight, we need to find ways to take calories out of the food choices we make, as well as find ways to add physical activity back into our lifestyle. Those who make lifestyle choices that help them manage calories have the most success when it comes to managing their weight.