Obesity: from molecules to man

Obesity is now a major public health problem in both developed and developi ng countries. In the UK over 16% men and 17.5% women are obese, an increase of more than 100% since 1980. However, interventions to prevent and treat obesity are hampered by an inadequate understanding of the aetiology of thi s condition. The present paper considers the current state of knowledge reg arding the causes of obesity, including some of the genetic, metabolic, beh avioural and environmental factors which influence energy balance. The pres ent paper comprises The Nutrition Society Medal Lecture and focuses in part icular on the research carried out at the MRC Dunn Nutrition Centre in Camb ridge. It argues that despite decades of intensive research there is relati vely little evidence of genetic or metabolic defects to explain the majorit y of cases of human obesity. Instead we must look to behavioural and/or env ironmental factors which may be underpinnings the current epidemic of obesi ty.