You might want to add some details to get the best responses from the diet and exercise experts, as it depends a lot on what the fighter needs to accomplish:

Weight class, current weight (and fat percentage if you know) and height, age, need to add muscle or strength?, etc.

A fighter needing to reach a distant weight class is in a very different (esp. related to diet) situation than a guy who is already well within his weight target.

A guy with a lot of fat, or even just a heavyweight vs a featherweight, can lose weigh more easily, etc.

So basically: Where are you? and Where do you need to go?

Otherwise you can follow most any 'diet' since some boxer somewhere is likely following any stupid diet you can name, even this one


--
HerbM