The Japanese live longer than almost anyone else on the planet—and this may be largely because their country has one of the lowest obesity rates in the world. One of their tricks for calorie control is a cultural practice known as hara hachi bu, which means eating until you feel about 80 percent full. At that point, your stomach is likely 100 percent full; your brain just doesn't know it yet.
Try to chew your food 20 times before you swallow. Slowing the pace of your eating makes it easier to recognize that 80 percent full feeling.