I'm going to be switching to one of these two
- https://www.amazon.com/gp/product/B06XX65GS1
- https://www.amazon.com/gp/product/B072KL928F
For other food, stick to eggs, burgers, steaks, fish and chicken. Pocket steak is a thing.
On the running thing, I haven't been running as of late, but that burns a ton of calories in the near term, and drops water weight from sweat. If he hasn't yet done so I'd suggest hill runs and fartleks over steady state flat runs.