Is eating less or more causes reducing or gaining weight?

Diet: You will gain weight if you eat more and do not burn these additional calories through exercise. Our metabolism slows as we age unless we exercise regularly. If you eat the same as time goes on, do not exercise you will gain weight. Best wishes.

Yes but complicated: If eat more you gain weight and less you loss weight . But so many other factors will play a role like your level of activity, the type of food , your basic metabolic rate, your metabolic hormonal levels.

Yes: You loose weight when you burn off more calories than you take in. You gain weight when you take in more calories than you burn off. @3500 = 1 pound.