Willpower, schmillpower. Yes, it's important to maintain healthy habits, but
a growing body of research is fingering a handful of hormones for the
relentless hunger and overeating that makes some people feel that it's
impossible to lose weight. A few under investigation: ghrelin, which stimulates
appetite, and leptin and oxyntomodulin, which suppress it. In one study,
volunteers who were deprived of sleep saw their levels of ghrelin soar — making
them ravenous — while their levels of leptin plummeted. This may explain why
people who are chronically sleep-deprived (snoozing less than seven hours
nightly) tend to be more overweight than those who get plenty of z's.
"Leptin normally signals the brain that your fat stores are large enough,
so when levels of the hormone are low, the brain assumes you need more fat and
triggers cravings for high-calorie food," says sleep and obesity researcher
Gregor Hasler, M.D.
To restore balance: Getting seven to nine hours of shut-eye a night
instead of scraping by on just six has been shown to lower your risk of
overeating and obesity by 23 percent, in part by restoring your leptin levels.
Even just one extra hour of slumber can make a difference. You should also
avoid fatty foods, and not just because they're chock-full of calories! Though
researchers don't yet understand why, they've found that calorie for calorie,
carbohydrates and proteins are significantly more effective at suppressing
appetite — and tummy rumbles — than fats. So whenever possible, swap high-fat
foods for those loaded with protein and complex carbs such as oatmeal, fresh
veggies, and whole grains.
Irritable Bowel Syndrome (IBS)
Some of us get headaches during stressful times, or feel just plain cranky
and irritable. But if you carry stress in your stomach instead of your head, it
could be because many of the same hormones and neurons are at work in both
places — a fact that's led some doctors to dub the gut the body's "second
brain." Take serotonin, for example. It's best known as the brain chemical
that impacts mood. But 95 percent of the serotonin we produce is actually
manufactured in the gut, where it plays a role in digestion. Recent studies
suggest that abnormal levels of serotonin may be one cause of irritable bowel
syndrome, a condition that causes chronic abdominal pain, cramping, and
diarrhea and/or constipation for millions of Americans. "And since up to 90
percent of sufferers are women, some whose IBS symptoms get worse around
menstruation, the flux of estrogen and progesterone may also play a role,"
says gastroenterologist George Arnold, M.D., a clinical professor of medicine
at the University of Pittsburgh School of Medicine.
To restore balance: Paxil, a drug designed to treat anxiety and
depression by upping serotonin levels in the brain, can also help relieve IBS
for patients with tough-to-treat symptoms — even when they're not depressed,
according to a study of 110 IBS sufferers conducted by Arnold. "Considering
the amount of serotonin being produced in the intestine, we think Paxil must be
doing something to the nerves in the gastrointestinal tract," he says. More
than 60 percent of Paxil-takers in his study had fewer IBS symptoms — and a
brighter outlook on life — compared with 26 percent of placebo-takers.
But before you call your doctor for a prescription, try increasing the fiber
in your diet. In phase one of Arnold's study, one in four IBS sufferers reduced
pain and bloating and felt much better after simply eating 25 grams of fiber a
day, which is the USDA-recommended dose. Although fiber may or may not
influence the hormones in the gut (no one knows for sure), it does help expand
the diameter of the large and small intestines, which eases painful muscle
contractions, according to Arnold. Try adding oatmeal and other whole grains,
plus raw fruits and vegetables, to your daily diet.