What does the man with the most Olympic medals of all time eat for breakfast?
Nowadays he opts for a large bowl of porridge, a large omelette with ham and cheese, fresh fruit and coffee - but back in 2008 things were a whole lot different.
Back then, Phelps would eat around 12,000 calories a day.
He'd start the day with:
Three fried egg sandwiches with cheese, lettuce, tomatoes, fried onions and mayonnaise
Two cups of coffee
One five-egg omelette
One bowl of grain
Three slices of French toast
Three chocolate chip pancakes.
And that was just for breakfast.
After that Phelps would have pasta, two large ham and cheese sandwiches and 1,000 calories worth of energy drinks for lunch. Dinner would be more pasta, pizza and energy drinks.
These days Phelps prefers to have a foot-long sandwich for lunch, and then grains, meat and veg for dinner.