Understanding the pathophysiology of obesity—the relevance of weight loss strategies through behavior modification

Obesity is a chronic, progressive, and relapsing disease that can contribute to morbidity, reduced life expectancy, and adverse health outcomes. The prevalence of obesity increased worldwide in the past 60 years, mainly because of changes in our environment and society. With the technical revolution of the last century, new modes of transportation and working conditions, automatization, and computerization, human energy demands have decreased. In parallel, the availability of energy-dense food, refined carbohydrates, and fat has markedly increased. These developments in society clash with biological factors that predispose humans to the development of obesity. At the individual level, obesity is the result of a long-term imbalance between too much energy consumed and too little energy expended. Therefore, lifestyle and behavior interventions aimed at reducing calorie intake and increasing energy expenditure target the root causes of obesity. However, both at the individual and population level, obesity prevention and treatment strategies that are based only on behavior modification are frequently not successful in the long term. The limited effectiveness of behavior interventions on weight loss are explained by complex and persistent hormonal, metabolic, and neurochemical adaptations that prevent weight loss and promote weight regain. However, behavior interventions lead to important health benefits beyond weight loss and are therefore an integral part of obesity management. This review discusses how a better understanding of the pathophysiology of obesity can influence weight loss strategies through behavioral modification. The complex factors contributing to the development of obesity require a multimodal long-term approach that is based on behavior interventions but may also include pharmacological or surgical approaches. The treatment paradigm has recently shifted from simple weight loss strategies towards treating obesity as a multisystem disease.