[Weight maintenance after weight loss - how the body defends its weight].

Mean weight loss of most conservative therapeutic weight loss programmes is about five to six kilograms after one year. In our "obesogenic" environment it is difficult for persons to maintain the new weight. Also continuation of the programme cannot prevent a moderate weight increase in the follow-up year. The reasons for this are not clear: individual lifestyle, environmental and genetic factors may play a role, but also the complex regulatory system of the body "to defend its weight". Nevertheless, for weight maintenance a lifelong change of lifestyle is of critical importance. Concerning nutrition a fat-reduced diet with a decrease of energy density together with regular eating habits and adequate portion size promises the greatest benefit and is likely to allow sufficient satiety. © Georg Thieme Verlag KG Stuttgart · New York.