
I never asked him that but i can if you want me to?
I can say 100% this is true, i sat 15 feet away from the guy for almost 5 years. He'd eat 3-4 salmon fillets at a time for lunch with veggies and rice. Probably weighes around 185 pounds.
Not that big at all, been one of the top Ironman competitors in Texas for 4-5 years. He used to tell me his "short" weekend runs were 12-15 miles.
I think when you have spent your entire life training for triathlons and Ironmans, this might be possible. Not sure, but the guy is 100% legit. He's sit at his desk with a tens unit hooked up to him.
He's probably on the extreme high end for calorie consumption but it's not out of the question. When I did cycling stage races - multiple days in a row where we did 60+ mile or more races- I could barely keep up with calorie needs. That's why you lose weight in such events. I raced at 175 pounds and ate about 4000 cals a day. Hard to keep track though because most of those calories are liquid form. And you do get sick of eating.
The example you give of him eating 4 salmon filets isn't all that many calories. At 160 cals each per filet, with rice and veggies, that's less than 1000 calories. I can get nearly that from two medium sized bags of peanut m&ms.
A 15 mile run for an average endurance athlete is less than 100 calories per mile. So he burned less than 1500 calories. For seasoned runners its more like 80 cals per mile because you get more efficient and burn less. So he burned a bit more than his lunch

On the other hand bodybuilders seem to pride themselves on gluttony. Eating a lot of food is some sort of badge of how hardcore you are.