Eating can be a fun, pleasurable, satisfying, nourishing, social, life-sustaining thing. But if your brand of eating interferes with the good functioning of your life - that's when it is a problem that needs fixing.
It's the same with your weight. There is no number that you need to artificially impose on yourself. But if your weight impinges on the good functioning of your body, your health, your comfort, your agility, your grace - that's when it's a problem that needs fixing.