For the past few years you've been doing all the right things: you're working out six times a week for one whole hour each time. You're cutting back on calories. A lot. You've even cleaned out all the unnecessary emotional baggage from your closet. So why are you gaining weight instead of losing?

Surprise, surprise, you're probably not eating enough...

Eating inappropriately is a mistake many people make, women in particular. For fear of packing on the extra pounds, they start the day with no breakfast at all but black unsweetened coffee. For lunch, they have a salad with three cubes of grilled chicken and a couple of walnuts (fat-free dressing, of course). For dinner, seven-eight hours later, they eat a tomato soup and two crackers. Dessert, if any, would be a pear or an apple.

Anyone having survived for a longer period of time on a frugal menu like the one above won't be losing any weight, no matter how active a lifestyle they maintain. On the other hand, they won't be gaining any weight either - unless they have days when they binge. Which most people do, especially at night, but tend to conveniently forget...

What's happening is the following: whenever you drastically restrict your calories for more than approximately two months (this timeframe varies slightly from person to person), your body goes into starvation-mode. In other words, after you have shed 20 pounds in record time, your weight loss will suddenly plateau and then taper down to nothing at all. And you will only maintain this new weight if you manage to stay on this barely-there diet for the rest of your life. Few people can endure it for long, and the ones that do face an even harsher reality: when they finally do overeat (which 99% are bound to do), their metabolism has become so ineffective that their body will hold on to every calorie fed to it - just like a starving person would. In essence, your body will treat your having eaten one little donut as though you had gobbled up three...

Not only is it a surefire way to gain weight but you're also putting undue stress on your digestive system. And you're probably not getting enough nutrients - ever. Not during your lower calories days, and not during your binging days either because you're probably eating calorie-dense food with poor nutritional value.

Aggravating your problem is the fact that you've been doing the same type of exercise for years. It doesn't matter that you break a sweat so powerful you look like you've participated in a wet T-shirt contest each time you exit the spinning room or that you use every machine possible in your gym’s vast weight room. You've followed the same workout routine for so long that your body has become tremendously efficient at doing it. Unfortunately, the more efficient your body is at exercise, the fewer calories it burns.

Not eating before working out doesn't help either. Instead of burning fat, your body is forced to use muscle instead for fuel, as the easiest way for it to get energy is to break down muscle mass. Your body can convert specific amino acids - the building blocks of muscle - to glucose, the sugar that powers human activity.

These two problems are easily remedied, however. Simply exchange your cardio days into anything else but what you're currently doing: if you spin, try running; if you take kick-boxing classes, use the elliptical machine. Use a fitness magazine or a trainer to create a new weight-lifting program. And have a snack before each workout! To break your bad eating habits, try the following step-by-step plan by my colleague nutritionist and trainer Sondi Carter:

Week 1: Start with breakfast. Breakfast is called breakfast for a reason...to "break" the "fast" from overnight. Breakfast jumpstarts your metabolism for the day. Try eating a piece of toast, fruit, or yogurt until your tolerance builds up for more fuel in the morning.

Week 2: Add an afternoon snack. Eating something small between lunch and dinner will help to curb your ravishing appetite by dinner and avoid over-eating at the dinner table. A handful of nuts, raw vegetables or fruit are perfect examples of afternoon/pre-workout snacks.

Week 3: Build up your breakfast. By now you should be able to tolerate a little more in your stomach at breakfast time. Try adding a bowl of cereal or oatmeal, and or some egg whites to your morning meal. Breakfast is not only the most important meal of the day, but it should be the biggest. Remember food is fuel for your body and brain...without enough, expect to crash by lunchtime.

Week 4: Add a mid-morning snack. If your tummy can't tolerate too much at breakfast, add a mid-morning snack to re-fuel. Again, nuts, fruit/vegetables, and yogurt are great choices.

Week 5: Aim for eating every 3.5 to 4 hours. It may seem you're eating constantly, that's because you are! Eating smaller meals every few hours throughout the day will not only keep you fueled and focused, it will also rev up your metabolism. It takes energy to digest your food (also called the thermic effect of food), so by eating every few hours your metabolism will remain elevated throughout the day, so you’ll be burning more calories from morning to night.

Week 6: Practice on the weekends. Try out your new eating habits on the weekends. We all know that weekends are time to unwind when it comes to food, but you can still implement these eating strategies successfully. By doing so you'll be less inclined to binge when tempted.

IMPORTANT: DON'T FEEL GUILTY IF YOU "CHEAT." Guilt only leads to binging. Most people think, "Well, I blew it so I might as well eat the whole pie." Think of that extra piece of pizza as a "treat" because you deserve it! Get back on track the very next meal...You don’t have to wait until Monday morning, start now.