Male 65 years old that i know is having a hard time losing weight. doesnt eat much. doesnt work out too much. large belly. does drink hard seltzer almost nightly. light chain disease as well but not the bad kind yet. ideas on how to lose it?

There is no magical wand for weight loss except diet and exercise. If he does not eat much but if he eats high calories foods, diet is still a problem. Hard seltzer has close to 100 calories for one can. For sure, he has to start exercise and gradually increases the time and frequency. He knows he has light chain disease so I guess his doctor already checked for thyroid issue.

He is eating more calories than he burns. Always the cause (usually). Get the app Cronomoter and monitor for a few days and it will become clear what to do. Eating less is always easier than exercise. Good luck.