One way to improve your eating habits is to realize that life is full of choices and that is the case when we eat as well. Sometimes we need to ask ourselves, have I eaten enough already? Am I really hungry or am I bored, upset, etc.? Doing that might change your mind about some unneeded eating. When you do eat, choose healthier options. Eat meals containing ample protein and lots of vegetables. Snack healthily when you snack.
Be sure to get enough exercise too as it is much easier to maintain a decent weight if we exercise regularly. Small changes can have large beneficial effects over time, just as in investing!