Losing weight is a matter that requires great perseverance and determination. First of all, what is the reason why he is unwilling to lose weight? Is it too tired from work? Still lack of motivation? Or is it inertia?

Secondly, I'd better know some scientific methods to lose weight. He promised to lose weight, but he didn't necessarily know which method was effective. He didn't know how to do it, so he didn't do it, or he didn't stick to it for two days.

Finally, don't take losing weight as his task. It is better to find a way to turn this process of losing weight into his hobby. For example, find an exercise that both of you are interested in and is helpful for losing weight, and then do it together at a fixed time every day to make it a habit. After a long time, the effect came out. Losing weight is a big project, which requires a lot of efforts. Losing weight is also a self-discipline problem. Others can only give advice, and you still need to decide what to do. I hope it helps you.