Intentional weight loss: patterns in the general population and its association with morbidity and mortality.

The question of whether intentional weight loss increases the longevity of obese individuals is important, given the high prevalence of obesity and co-morbidities in industrialized countries, and the high prevalence of intentional weight loss in such populations. A number of studies suggest that both weight loss and weight fluctuation are associated with increased mortality. Factors such as smoking status and pre-existing illness, however, have to be considered in relation to these findings. A study controlled for smoking status and pre-existing illness, found that intentional weight loss by overweight, white, US women, consistently reduced mortality in those with obesity related co-morbidities. An Indian study, involving individuals with previous myocardial infarction, found that dietary intervention reduced mortality substantially. Those losing > 5 kg had the greatest reduction in both total and cardiovascular mortality. In both the above studies, weight loss was approximately 10% of initial body weight. Preliminary evidence suggests that modest intentional weight loss is associated with increased longevity in individuals with co-morbidities.