Evolution of the understanding of the role of exercise in obesity and its complications.

Exercise is often added to energy intake restriction in treatment programs for obesity. The effects of exercise alone on body fat mass is highly variable, and less efficient than diminishing energy intake. However, exercise has additional, beneficial effects on most of the metabolic risk factors for cardiovascular disease and non-insulin dependent diabetes mellitus. A problem is the feasibility of training programs. Conventional, aerobic type of interventions are difficult to adhere to because of their strenuous character and because of boredom. Recent findings of essentially similar effects of low intensity programs, creating Metabolic Fitness appear more attractive and useful. The final proof of a potential protective effects of exercise against cardiovascular disease and diabetes needs very difficult, time-consuming and expensive studies, if at all feasible to perform. The current evidence for protective effects is highly suggestive, and the beneficial effects on the risk factors for these diseases have been demonstrated. Provided that feasible methods and motivation are available we can therefore now probably recommend increased physical activity.