It sounds like a joke: if you want lose weight, go hungry. But I’m serious. A lot of the obesity we see exists because our bodies have forgotten how to be hungry.
We are designed to fast occasionally. Our bodies are tuned to put on weight in times of plenty and burn fat in lean times. Not only has modern society supplied us with a fairly reliable supply of food (generally a good thing), we also have constant access to snacks, candies, cookies, and (perhaps worst of all) sugared drinks like soft drinks, coffee, tea or even fruit juices. So we are almost never really hungry. At the first sign of hunger, most people grab a little something. We do this mostly without thinking throughout the day.
The result is that the body “forgets” how to deal with a drop in blood sugar. Try a little experiment with yourself: After breakfast, don’t eat anything at all. Try to see how long you can go. Observe your own reactions. Most people will start to feel hungry, then anxious, then shaky and/or cold. You may grab a snack out of habit and have it in your mouth before you know what you are doing. Finally, it becomes hard to think of anything other than your hunger. I remember that when I tried this experiment the first time I had to consciously remind myself that what felt like dread was just hunger, which wasn’t going to kill me (not in one day), and that the anxiety I felt was not a forewarning that something bad was going to happen.
Your body can be trained out of this. There are parallels in exercise. When I started running again after not doing much for exercise for years, I could barely go a mile. But as I kept doing it day after day, all the systems in my body started to tune up and learn how to process energy and move muscles efficiently.
In the same way, skipping all snacking is hard at first because the systems that mobilize body fat for energy have become inefficient. The body has come to rely on a regular supply of carbohydrates or fats from the outside. It doesn’t know how to deal with falling insulin levels. It probably even overreacts because, as a result of the constantly high levels of insulin, it has down-regulated the activity of the insulin receptors (and over years this down-regulation leads to insulin insensitivity and type 2 diabetes). But as you eat less often, and eat smaller meals, the body adapts. Just as with exercise, the more you do it the easier it is. And you are living more in line with the way our bodies were designed by evolution to function. And when the body needs some energy, it starts pulling from the fat stores it has squirreled away for exactly this purpose, without bothering the mind much at all.
I think people might have an easier time with dieting if they saw it not as deprivation, but as active training to strengthen the metabolic machinery.