I have a friend who is a Randonneur, ultracyclist, endurance swimmer, and ultra distance hiker. He weighs over 300 pounds.
Back in the 80's I had a friend who was a track cyclist. He was fast, strong, had great endurance, and weighed over 250 pounds.
Neither of those guys could outrun their appetites. I don't think it matters whether it's short/hard or long/easier.
I think exercise is an important part of maintaining a healthy body, but managing intake is just as important. Managing intake is also much harder.