DH has 3 diners everyday. The first will be a proper meal, say spaghetti bolognese, he will also polish off the children's meals if there's any leftovers - often before they've even said they're finished. Second meal will be some kind of sandwich, so tonight it was turkey and avocado, other times it might be peanut butter and banana. He will then finish with a massive bowl of cereal.
Full disclosure, he does walk 6 miles a day. However, he always has a hearty canteen lunch (massive portions). I know this because he frequently instagrams his work meals. He also tells are children about them when he get home and they often involve puddings like profiteroles or crumble.
He's a perfectly healthy size. But aibu to think this is unusual behaviour. He's just had a go at me because I raised my eyebrows when he was pouring out his massive bowl of Cheerios.