It's 4 p.m. Your workday is almost done. You're not really hungry,
but like yesterday, same time, you've got a hankering for some
chocolate. Not just any chocolate, but a Nestle Crunch. So you head
over to the office vending machine, drop in a few coins ... and just
like that, your well-intentioned efforts to regularly eat only healthy,
weight-loss-friendly foods are foiled -- again.

You're not alone. Many women routinely experience sudden and
irresistible food cravings for potato chips, ice cream, cookies and,
yes, chocolate. Just what triggers these overpowering desires for
certain foods?

"Cravings are a natural part of our relationship to food," says
Harvey Weingarten, Ph.D., the president and vice-chancellor of the
University of Calgary in Alberta, Canada, who has conducted extensive
research on food cravings. According to Weingarten's research, up to 97
percent of women have felt cravings (compared to 68 percent of men),
and we give in to our urges at least half the time. There's a big
difference between cravings and hunger pangs. "When you're hungry,
you'll eat anything," Weingarten points out. "Cravings are very
specific. People crave a certain type of food, like chips or chocolate
-- and within that category, even a particular brand."

Though cravings seem to overtake us without warning and without
reason, research shows that they are actually very predictable,
arriving at particular times and in particular situations.

You've probably noticed that you feel your strongest food yens at
specific times of the day -- or month. Here are the whens and the whys
of cravings:

* During the midafternoon slump (from about 3-6 p.m.) "By far the
greatest number of cravings occur late in the day," says Marcia Levin
Pelchat, Ph.D., of the Monell Chemical Senses Center in Philadelphia,
an institute that does research on taste and food preferences. "That's
when our blood glucose drops, making us sluggish and in need of a lift"
All it takes now is a cue -- a fast-food billboard on your way home or
a co-worker's candy bar -- to bring on a major craving.

* When we're stressed out, upset or bored Bad moods frequently give
rise to cravings: We imagine that if we eat a cookie or a chocolate
bar, we'll feel better -- and often we do. Carbohydrates sweet or
starchy foods -- increase the secretion of the brain chemical
serotonin, which in turn can improve mood.

* Before your period Research shows that many of our cravings for
chocolate and carbohydrate-rich foods are particularly intense in the
days leading up to menstruation. Experts theorize that women may
overeat carbs in an attempt to raise serotonin levels to counter the
bad moods and mild depression related to PMS.

Also, we actually need more calories premenstrually, so it would
make sense we might experience more cravings if we're short on energy.
Although there have been a number of studies examining cravings and the
menstrual cycle, scientists still don't know exactly why some women
crave carbs, chocolate and other sugary foods before their periods.

* When it's cold and dark out Short, wintry days can make us crave
carbs like bread and pasta. People who suffer from Seasonal Affective
Disorder (aka SAD, which is depression related to diminished
sunlight-exposure) may be especially affected and crave carb-rich foods
to help themselves feel better.

* When we're accustomed to eating Brian Wansink, Ph.D., a professor
of nutritional science and marketing at the University of Illinois at
Urbana-Champaign, who runs the university's Food and Brand Lab, has
found that we often crave foods with associations to happy times we've
had in the past. When we're at the ballpark, for example, we might
crave a hot dog with the works; if a summer-night trip to the ice-cream
parlor was a family tradition, we may find ourselves craving an
ice-cream cone when the weather gets warm.

How to manage your cravings

Forewarned is forearmed: If you know a food craving is going to
strike, you can substitute something -- a healthier snack, a
distraction, even a well-planned breakfast or lunch -- rather than
regularly surrendering. Here are proven methods to help tame your
cravings:

* Eat carbs, protein and a little fat at every meal and snack. When
we eat meals that are lacking in one kind of food, we may be more
likely to crave it later -- something for dieters on high-protein,
low-carb regimens to keep in mind. Eating a varied diet, you'll feel
better and have more energy and better concentration. Protein and fat
take longer to digest than carbs do, so including them, along with more
fiber, in any meal means that you'll feel satisfied longer. When our
meals are monotonous -- the same day after day -- we're practically
guaranteed powerful cravings. "That's true even if your diet is
nutritionally adequate," says Marcia Levin Pelchat, Ph.D.

Too often we'll skip breakfast or forget about lunch, only to feel
a craving strike later in the day. Think ahead and plan a healthy
breakfast, lunch and dinner that consist of carbohydrates, protein and
good fats. Your snacks, too, should be a combination of protein, carbs
and a little fat, especially in the late afternoon, when cravings seem
most urgent. Any of the following snacks can fend off a trip to the
candy machine: whole-wheat pita bread with hummus; a pear with lowfat
cheese slices; a quesadilla (made with a whole-wheat tortilla); raw
veggies with lowfat cottage cheese; wholewheat crackers with peanut
butter.

* Craving-proof your home and office. The simplest way to quash a
craving is to ban crave-worthy foods from your environment. If you do
buy snack foods like chips or cookies, choose small packages or
individually wrapped portions to avoid going overboard. Meanwhile, here
are three ways to make healthy, lowfat snacks easily available for
regular indulgence:

1. Cut up and bag carrots, radishes, broccoli and celery sticks in advance and pack them with some lowfat cheese.

2. Buy light microwave popcorn packages to have on hand, and sprinkle some Parmesan cheese on top.

3. Keep fruit washed and ready to slice into a container of lowfat yogurt.

* If your food cravings hit when you're anxious or stressed, seek
consolation in other ways. Address your stress. What is it that you
really need? A comforting conversation with a coworker, a walk, or a
shoulder massage from a friend may do the job. If reassuring "comfort
foods" are your downfall, find some that are healthy, but still
satisfying -- a vegetarian casserole, maybe, or mashed potatoes made
with lowfat milk.

* Give in sometimes. If your craving is especially persistent,
denying yourself that cookie or bag of chips will only make the urge
more intense. Allow yourself a moderate portion of the food you crave,
deciding on the amount you II have before you dig in.

chocolate What to eat instead Let's face it, there's no substitute
for chocolate. Eat a little bit of it, and savor every bite.

ice cream What to eat instead Try 1/2 cup of light vanilla ice
cream (100 calories) topped with strawberries rather than full-fat
vanilla ice cream (270 calories per A cup). Or go for Haagen-Dazs
Chocolate Sorbet, which tastes extraordinarily rich but isn't: 130
calories and o fat grams per 1/2 cup.

potato chips What to eat instead Salted popcorn: 4 cups (a whole
bowl!) of light microwave popcorn has just 120 calories. If you really
need to have some chips, eat the baked kind with 110 calories per
1-ounce serving vs. deep-fried with 158 calories.

cookies What to eat instead Lower-fat cookies or granola/fruit
bars, Try: Whole-wheat Fig Newtons (2 cookies have 110 calories);
Healthy Valley Raspberry Jumbo cookies, which are fat- and
trans-fat-free (1 cookie has 80 calories); a Nature's Carob Chip Choice
Granola Bar (80 calories).

french fries What to eat instead Homemade baked cheese fries: Spray
potato wedges with olive-oil-flavored Pam and sprinkle with salt; roast
at 4000 F for 40 minutes; sprinkle with some reduced-fat grated Cheddar
cheese and bake for 5 more minutes.

Annie Murphy Paul is a freelance writer in New York City.