How to Lose Belly fat? Do Ab Loungers work?

We eat pretty good at home, but he snacks too much & eats too much fast food at work. He doesnt have many options for a healthy lunch
My husband is really tall with a huge frame a very large chest & arms which are tone. His belly is too round & his butt & thighs are HUGE, even when he was skinny he always had a huge butt (runs in the family lol)
What would be the best way for him to tighten his belly & possibly loose the butt.

Me on the other hand, am very tiny, but still have a bit of a pouchy belly from my 3 yr old & 1 yr old. So I told him we would start working out together.
Do the Ab lounger things work?