Health is not just about what you eat….portion control and how much you eat matters. Even if you eat a lot of healthy food, it is not good for you. the digestive system cannot handle too much food at once. And if you eat a small amount of unhealthy food, the body can rid itself of garbage, toxins etc. in small doses. So , as the Rambam said, quantity is just as important or more so than quality.
to lose weight people are also finding portion control is helpful. You dont have to limit your diet and cut out all types of foods you may like. Just take small portions . In other words, instead of a plate full of pasta, take a small sized plate and just put about half a cup of pasta or so. That will fill you up too but not harm you the same way.
Americans tend to think we need huge amounts of everything: a big steak, a big sandwich, a huge cup of ice cream, a giant cup of coffee etc. No, we do not. In europe and many other countries portions are much smaller. People have small cups of coffee, small portions of bread, a tiny cup of ice cream, a very small amount of meat and a balanced plate, not emphasizing only one type of food. A meal should not be just a big steak and some salad. Rather try to have some vegetable side dishes or entrees and then a smaller portion of meat along with, perhaps, a bit of rice or some roasted vegetables and so on. Balance is the key. To balance out meat you need some vegetables, perhaps some lemon on a salad, some sweet foods like some fruits etc. This is the concept of yin and yang in Japanese medicine.