While, in principle, I don't feel that armchair specialists and YouTube videos are the way to approach health matters, your response tells me that you have an avoidance issue going on. Plus, she is your wife and she has a right to say when she is concerned about your health.

Diet is also only a small part of anyone's belly fat problem. Stress is often a bigger factor and no amount of dieting is going to help if you don't deal with stress first.

I am not making a judgement over whether or not you lead a stressful life - I wouldn't have a clue. But many of us do deal with stress and bury it rather than deal with it. Yes, choose the healthy options as much as is possible and practical, but make them count too.