It's not imperative to exercise to lose weight. Not at all. Is it "better" to incorporate exercise? Surely.

It's a formula, Tim. Once you learn your basic metabolic rate......it's a math formula from there. (________) calories to "maintain". Any calories over that will see you gain. And deficit will see you lose.

3,500cal./pound......and a 500 cal/day deficit will see you lose 1#/wk. It's simple math.

Good luck to you.