Exercising to lose weight is a not a waste of time but the real only way to shed those unwanted kilos is to eat less. Exercise does help you increase your lean body tissue (muscle) which helps increase your metabolic rate. It is also very good for your mood and is a stress release which motivates you to make better choices of food. There are different types of exercise and, while undoubtedly physical activity is necessary for cardiovascular fitness, muscle strength, metabolism, core stability, posture and body shape, it is not the answer for losing weight on its own. When exercise is combined with a cut in kilojoule intake, the weight loss can be as high as 7.5 kilograms in just 12 weeks. While diet is more effective for short-term weight loss, evidence suggests a continuing exercise program outweighs the value of diet in the maintenance of weight loss over two or more years. In a second or two we can easily eat hundreds of kilojoules - which overweight people do - and it would take hours to exercise those off. The right food choices can reduce our kilojoule intake by thousands every day. It would take over five or six hours of exercise to get the same benefit. Each person has their own unique kilojoule reference point, which is the most kilojoules they can eat in a day and still lose weight without the need for any extra physical activity. People who exercise to lose weight also tend to pay less attention to their diet, which makes it even more difficult for them to lose weight. Exercise for weight loss is a serious long-term health risk because of the added load on the body's organs. We have to change our food choices to lose weight and be aware of our portion sizes.