Perhaps most importantly, from the human perspective, the researchers show that MCH is the closest thing yet found to a master-switch controlling appetite regulation and obesity. As such, future research into drugs that block MCH action will be of great interest to medical researchers and clinicians alike. Several natural substances are now known that regulate feeding behaviour. Perhaps the best known is leptin, which inhibits feeding. Failure to produce leptin, or defects in its receptor, will lead to situations in which people remain hungry despite being obese.
Few hormones seem to put a brake on consumption.
One is neuropeptide Y, or NPY for short. This is produced in greater quantities during fasting, and promotes feeding behaviour when injected into mice. One would expect that mice without NPY would eat less and burn more calories, but, surprisingly, NPY-free mice behave just like normal mice. This result led to speculation that several appetite-stimulating hormones cover for one another, should one of them prove defective. Like NPY, it stimulates eating.