Understanding the inner workings of your appetite can be a lot of information to process, but I hope that comprehending what's going on in your body will help you gain greater insight into the weight-loss process. Your body has a system for minimizing weight loss (believe it or not, it also has a system minimizing gain, too), but by adopting the change set out for you in this program, you will be able to override some aspects of that system and lose the weight you need to.

Exercise, for instance, activates some of the same pleasure circuitry in the brain as food. By producing pleasure -inducing brain chemicals called endorphins, activity can provide some of the comfort you may otherwise get from eating. Research also suggests that exercise can increase the number of dopamine receptors you have, good news if you have a naturally low count. (Short of going to a lab for expensive tests, there's no way to know whether you do or not; however, if many people in your family struggle with overeating or obesity or addiction, it may be a sign that you do have fewer dopamine receptors than normal.) These are just few other reasons why it's to your advantage to try and increase your activity level as much as you possibly can.

By cleaning up your diet, as you'll do gradually on this program, you're also going to be taking an important step toward controlling your hunger. One of the theories about why people eat too much junk food is that when you consume an abundance of fat and sugar, It disrupts all the signals that carry out normal appetite regulation. By reducing the amount of fatty and sugary foods in your diet, you're going to bring your body's hunger and satiety network back into balance.

The healthful foods that replace the junk food in your diet are also going to bring their own appetite-control benefits to the table. Many of these foods will be high in fiber and/or water. Fiber, a type of carbohydrate that helps give certain their bulk and that can’t be digested by the body, helps you stay fuller longer. Fiber slows down digestion so that your blood sugar level stays elevated and delays the release of some of the hormones that signal your brain that it's time to eat again. As an added bonus, foods rich in fiber tend to be lower in energy density: the fiber takes up space, but adds no calories.

Your diet should contain at least 25 g of fiber daily if you’re a woman, 38 g if you're a man.

Water-rich foods also help you feel full on fewer calories, according to extensive research at Pennsylvania State University. Water, like fiber, adds bulk to foods' calorie counts, which is why vegetables and fruit---the fruits highest in water---tend to be less energy dense than other foods. The scientists urges you to eat lots of salads and soups, two dishes that are particularly water-rich and have been shown to help people lower their calorie intake when they're eaten as an appetizer. If you start a meal with soup, choose one that has 100 calories or less per cup. Progresso, for instance, has about thirty-two soups that fit the bill.

Because most high-fiber and water-rich foods are fairly low in calories, they also allow you to eat more than foods that are energy dense (fatty foods like nuts, for instance, are considered energy dense because there are a lot of calories packed into each individual nut). This can help you deal with hunger, too, because hunger and satisfaction are often tied to expectations. If you're used to eating a large bowl of food but are served a small one, you may still feel hungry after you've finished eating its contents, even if what's in the small bowl has more calories. Being able to eat bigger portions should help you feel less deprived while still allowing you to cut calories.

There is, of course, a limit to how big your portions should be, and I don’t want to give you the idea that portion sizes don’t matter, even if you're eating relatively low-calorie foods. One of the biggest contributions to the obesity crisis sweeping this country is that many people consume portions that are simply too large. It’s an important issue. I do, however, want to acknowledge that we now live in a world where restaurants think nothing of offering (and many people think nothing of consuming) forty-two-ounce sodas and steaks the size of a hardcover books. It's easy to become accustomed to big portions; after a time, your brain associates them with satisfaction and anything less seems skimpy even if your stomach says differently. As you go from being big portion eater to someone who's satisfied with more moderate amounts, high-fiber and water-rich foods are going to help you make the transition. These foods will let you eat more (think of a big bowl of hearty vegetable soup versus a small cup of cream of broccoli, both of which may have the same amount of calories), feel less hungry, and keep your calorie intake in check.

I want to point out that all the recommended meals and many of the snacks in a healthy life diet contain a mixture of carbohydrates, protein, and fat. This is because eating all three of these nutrients together seems to be more satisfying than eating any of them alone; each brings something to the table. Protein may be the most satiating. Many studies show that people feel more satisfied and eat fewer calories later on after having meals rich in protein. Scientists aren't sure why protein is so satiating, but theorize that it may affect hormones that suppress the appetite. Carbohydrates have bulk; they expand your stomach and activate the nerves in the stomach lining that tell your brain to stop eating. They also raise your blood sugar level, providing both immediate and long-term energy. Fat's role is to slow down digestion, delaying the time before your stomach becomes empty and begins signaling your brain to eat again. Together, protein, carbohydrates, and fat are going to maximize how full you feel on the fewest number of calories.

There's one last element of appetite control that I want to mention that may surprise you: sleep. There increasing evidence that the amount and quality of sleep you get may affect your body weight (and not because tossing and turning burns calories!). Scientists are finding that lack of switches, and that people who are sleep deprived have increased appetites. The more we learn about the body, the more indication there is that all healthy habits are connected. Now we know that getting a good night's sleep and maintaining a healthy body weight are linked, too.