TY - JOUR AU - Ahima, Rexford S. T1 - Revisiting leptin’s role in obesity and weight loss PY - 2008/07/01/ AB - Maintenance of weight loss is often unsuccessful because of metabolic adaptations that conserve energy. Studies in rodents suggest that a reduction in leptin level during weight loss signals to the brain to increase feeding and decrease energy expenditure. In this issue of the JCI, Rosenbaum et al. examined this concept in obese patients who lost weight and were maintained at 10% below their initial weight (see the related article beginning on page 2583). Brain activity responses to visual food stimuli were visualized using functional MRI. Leptin levels fell during weight loss and increased brain activity in areas involved in emotional, cognitive, and sensory control of food intake. Restoration of leptin levels maintained weight loss and reversed the changes in brain activity. Thus, leptin is a critical factor linking reduced energy stores to eating behavior. Potentially, leptin therapy could sustain weight loss by overriding the tendency toward energy conservation. JF - The Journal of Clinical Investigation JA - J Clin Invest SN - 0021-9738 DO - 10.1172/JCI36284 VL - 118 IS - 7 UR - https://doi.org/10.1172/JCI36284 SP - 2380 EP - 2383 PB - The American Society for Clinical Investigation ER -