title: Metabolic vs. hedonic obesity: a conceptual distinction and its clinical implications.
abstract: Body weight is determined via both metabolic and hedonic mechanisms. Metabolic regulation of body weight centres around the 'body weight set point', which is programmed by energy balance circuitry in the hypothalamus and other specific brain regions. The metabolic body weight set point has a genetic basis, but exposure to an obesogenic environment may elicit allostatic responses and upward drift of the set point, leading to a higher maintained body weight. However, an elevated steady-state body weight may also be achieved without an alteration of the metabolic set point, via sustained hedonic over-eating, which is governed by the reward system of the brain and can override homeostatic metabolic signals. While hedonic signals are potent influences in determining food intake, metabolic regulation involves the active control of both food intake and energy expenditure. When overweight is due to elevation of the metabolic set point ('metabolic obesity'), energy expenditure theoretically falls onto the standard energy-mass regression line. In contrast, when a steady-state weight is above the metabolic set point due to hedonic over-eating ('hedonic obesity'), a persistent compensatory increase in energy expenditure per unit metabolic mass may be demonstrable. Recognition of the two types of obesity may lead to more effective treatment and prevention of obesity.
authors.affiliation: Weight Loss and Diabetes Center, Greenwich Hospital, Greenwich, CT, USA; Endocrinology Associates of Greenwich, Northeast Medical Group, Yale New-Haven Health System, Greenwich, CT, USA.
authors.forename: Y-H
authors.initials: YH
authors.lastname: Yu
authors.forename: J R
authors.initials: JR
authors.lastname: Vasselli
authors.forename: Y
authors.initials: Y
authors.lastname: Zhang
authors.forename: J I
authors.initials: JI
authors.lastname: Mechanick
authors.forename: J
authors.initials: J
authors.lastname: Korner
authors.forename: R
authors.initials: R
authors.lastname: Peterli
mesh_terms: D001069:Appetite Regulation / Q000502:physiology; D001835:Body Weight / Q000502:physiology; D004435:Eating / Q000502:physiology; D004734:Energy Metabolism / Q000502:physiology; D006706:Homeostasis / Q000502:physiology; D006801:Humans; D007031:Hypothalamus / Q000378:metabolism* / Q000503:physiopathology; D009434:Neural Pathways / Q000378:metabolism*; D009765:Obesity / Q000145:classification / Q000378:metabolism* / Q000503:physiopathology; D012201:Reward
keywords: Body weight regulation; energy expenditure; food reward