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'll have before you dig in.

Here's my tactic - If I decide to have that extra piece of chocolate then I stop at just one glass of wine. If it's the wine I really want then I'll pass on dessert. I like to think of my healthy "diet" full of "Yes, I can's" instead of "No, I can't". Good nutrition isn't about depriving yourself, it's about getting more of the good things!