When the calories burnt equate to food you can then eat maybe it's a problem...

Sumo, while fat, are also extremely muscular though. They're not just eating junk food, they usually have specific diets.

There are some people who eat junk food, don't exercise or exercise quite rarely and surprisingly they don't get fat.

Sumo wrestlers don't eat junk, they just eat an insane amount of calories. But the actual food is very healthy and balanced.