The article was published in the April 6 issue of Nature magazine. In the brain, there are pathways that potently affect both energy intake and expenditure. These pathways operate in normal individuals to promote stability of body fat through a process called homeostasis. When these pathways are activated by energy restriction, appetite is increased, energy expenditure decreases and lost weight is eventually regained. Recent breakthroughs have begun to clarify how defects in this biological control system can cause obesity in people.
Many studies show that weight regain is delayed when an exercise regimen is added to a diet program.
The research tested how the brain's hypothalamic pathways obtain information and regulate adiposity. Profound obesity in rats and in humans results from the mutation of key signaling molecules involved in this regulatory system. Each new hypothalamic pathway that is discovered can lead to a potential target for drug development in the treatment of obesity, says Schwartz.