Types of Diet Pills
There are lots of different types of diet pills, and each works in a different way.
Posted: February 9, 2010 | Views: 672
Understand the Physical Nature of Your Hunger
Eating is meant to be one of life's great pleasures, but the pleasure you get from eating is also a survival tool, meant to ensure that you'll want to eat and therefore stay alive. Pleasure, though, is just one of several different physiological mechanisms devoted to making your desire food. And not only do those mechanisms make you want to eat, but they also make you want to eat the foods that will sustain you the longest: those with a lot of calories.
The reason you get hungry, and what makes you feel full, are complicated. Scientists are just now begging to get a handle on the intricacies of appetite, and their work is far from done. In recent years, though, they've been able to tell us quite a bit about what causes hunger to strike and how the body turns the appetite on as well as off.
Most of the time your thoughts turn to food because your brain is getting a variety of different signals from your body urging you to eat. One of these signals comes from a hormone called ghrelin, which is produced when your stomach empties. When you begin eating, your brain gets the sale on your plate, with your body saying, "There's food here"! Get while you can" Gradually, some of the mechanisms that turn off your appetite start to chime in. As your stomach fills with food, the expansion triggers the nerves in your stomach's walls to send signals telling your brain to slow down. At the same time, ghrelin production ends, and that, along with the release of other hormone, sends the same message, letting your brain know you can stop eating now. Further input is received by a hormone called leptin, which originates within your fat cells. Leptin clues your brain into how much body fat you're carrying; if it's high enough, it contributes to the symphony of messages telling you that you can leave the dinner table.
It's really a very elegant and efficient system, except that there are all kinds of things that can conspire to throw it off. One problem is that it can take as long as twenty minutes for the I'm-full message to reach your brain, which potentially means (and usually does) that you'll keep eating beyond the point that you need to. Fortunately , that's a problem that you can override by pausing before you have a second helping or continue with dessert. Stopping to let your brain catch up with your body is one of the most powerful tools you have for dealing with physical hunger.
The other glitches aren't as easy to correct. Some research, for instance, has shown that many obese people are resistant to leptin; their brains don’t get the message that they have enough body fat, which may be one reason they have trouble controlling their appetite. Also, whenever you lose weight, your body will try to get back to its set point the weight range that you're programmed to maintain by changing levels of some of the hormones that control your appetite. Leptin production will drop so that your brain doesn’t get the don’t-eat signal it normally would, while ghrelin production will rise so that it gets more of the do-eat message. If you've ever found that after losing a certain amount of weight you suddenly feel like eating everything in sight, this could be one of the reasons.
Complicating matters is the fact that hunger and food cravings are also triggered bu the motivation and reward centers of your brain. Instead of inducing you to eat because your stomach is empty, certain brain chemicals encourage you to eat for pure pleasure. "Go out, get something delicious and devour it," they say. "It's going to feel really good!"
And, of course, it does, but this isn’t just hedonism. Like our ancestors who lived through times when food could be scarce, we're hardwired to desire foods high in calories, even though we don’t need to pack in as many calories as possible every chance we get for survival purposes. Even so, the motivation and reward centers of the brain still operate on the assumption that the more calories, the better, which likely explains why foods like cookies, ice cream, and chips are so alluring.
Some people, of course, have harder time resisting high-calorie foods than others, and now scientists are discovering that there may be a physiological reason why. One of the most interesting recent findings is that the brain chemistry of some obese people is similar to the brain chemistry of drug addicts and alcoholics. Both groups of people have lower levels of receptors for dopamine, a chemical that is part of the brains motivation and reward system. Dopamine drives you to grab for something that will bring you pleasure. If you're low on receptors for the chemical, it may be that you don’t process pleasurable stimuli, whether it's from food, alcohol, or drugs, as easily as the average person, so it takes more of it to bring you to the point where your brain says "I've had enough" and signals your body to put on the breaks. Another possible explanation is that if you're short on dopamine receptors, then you won't be as receptive to other pleasures in life, making you vulnerable to the things that do give you pleasure in this case food.
For a long time, people who said they were addicted to food were dismissed as overstating the case, but this new research lends some credibility to the argument that certain people have physiological differences that make them more susceptible to overeating. Another possible difference between food addicts and regular eaters is their levels of serotonin, a brain chemical that also affects appetite. Serotonin affects mood, and many antidepressants work by readjusting the level of serotonin is the brain. It’s also believed to active brain chemicals that depress appetite and block those that increase appetite. Some researchers believe that serotonin, or, more specifically, lack of serotonin, is behind cravings for cookies, candy, bread, and other sugary and/or starchy foods. These foods boost the release of serotonin, increasing the sense of well-being. The serotonin theory, though, is complex, because drugs that increase serotonin levels such as antidepressants tend a to promote weight gain not loss.
Scientists are also looking at the connection between stress and comfort foods. So far, studies seem to indicate that foods full of fat and sugar actually put the brakes on the release of stress hormones. But you probably don’t need a study to tell you that. If you hit your kitchen cupboards the minute you get home after stressful day, you know all too well that comfort foods do just that comfort us.
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