How to help spouse lose weight

I need some advice, my husband is trying to lose weight. Since we’ve been married he’s gained 60+ Pounds. Of course I love him and think he’s attractive no matter what but it’s starting to affect his health and energy levels. I honestly don’t even know how he gained that much weight. I cook us dinner at least 5 times a week so it’s not like we’re eating fast food everyday. Does anyone have suggestions on how I could encourage him or assist him in his goal?