Learned he's genetically pre-dispositioned to lose weight from diet versus exercise.

He found out through his data that he's gluten-sensitive and his body responds to protein. This has eliminated the guesswork for him. He has tried many other diets like KETO but didn't like the extreme constraints.
He's learned to cook stir-fries. Adds proteins and a lot of veggies. He now buys fresh and frozen veggies. Used to buy rib-eye and now chooses chicken or skirt steak. He found out he's genetically pre-dispositioned to gain weight from fats.
Time Advantaged Eating has had the biggest impact on him to lose weight.