Exercise has a huge upside for health but that doesn’t seem to necessarily apply to weight loss. While exercise is beneficial for numerous reasons, it's not the best way to lose weight. When it comes to reaching a healthy weight, what you don’t eat is much more important than an excessive emphasis on exercise (e.g., 30 minutes of running or swimming laps might burn off 350 calories or you could achieve the same calorie reduction by eliminating two 16-ounce sodas each day). Evidence is beginning to accumulate that dietary intake may be more important than energy expenditure level. Decreased physical activity may not be the primary driver of the obesity epidemic. Weight loss is not likely to happen without dietary restraint. When you exercise can be a factor in weight loss, as well. Years ago Candace B. Pert PhD reported that 20-25 minutes of aerobic exercise before breakfast could turn on fat-burning peptides that would burn for several hours. A study from Northumbria University, published in the British Journal of Nutrition, reported that participants lost 20 percent more fat when they exercised before eating breakfast.