Your 'Hunger Hormones'
How they affect your appetite and your weight
If there was a hormone in your body whose chief job was to make you feel
hungry, most of us probably wouldn't be too keen on it. (I don't know about
you, but having a healthy appetite has never been a problem for me.) But if
there was a hormone that decreased our appetites, we'd order buckets of
Well, let me introduce you to some hormones that do just those things: the
"hunger hormones," leptin and ghrelin.
Leptin is a hormone, made by fat cells, that decreases your appetite.
Ghrelin is a hormone that increases appetite, and also plays a role in body
Levels of leptin -- the appetite suppressor -- are lower when you're thin
and higher when you're fat. But many obese people have built up a resistance to
the appetite-suppressing effects of leptin, says obesity expert Mary Dallman,
PhD, from University of California at San Francisco.
Here's what we know so far about the "hunger hormones" and what we
can do to help control our appetites.
What We Know About Ghrelin
Ghrelin, the appetite increaser, is released primarily in the stomach and is
thought to signal hunger to the brain. You'd expect the body to increase
ghrelin if a person is undereating and decrease it if he or she is overeating.
Sure enough, ghrelin levels have been found to increase in children with
anorexia nervosa and decrease in children who are obese.
German researchers have suggested that ghrelin levels play a big role in
determining how quickly hunger comes back after we eat. Normally, ghrelin
levels go up dramatically before you eat; this signals hunger. They then go
down for about three hours after the meal.
But some researchers believe that ghrelin is not as important in determining
appetite as once thought. They think that its role in regulating body weight
may actually be a more complex process.