Conversion process: A huge calorie intake provides Phelps with crucial energy
As US swimming sensation Michael Phelps sets his sights on more gold medal wins at the Beijing Olympics this weekend, the BBC's Michael Hirst examines the part an extraordinary diet has played in the sportsman's remarkable success.
If it is true that you are what you eat, then here is the suggested intake if you want to become history's most successful Olympian:
For breakfast: three fried egg sandwiches, with cheese, tomatoes, lettuce, fried onions and mayonnaise, followed by three chocolate-chip pancakes; a five-egg omelette; three sugar-coated slices of French toast and a bowl of grits (a maize-based porridge), washed down with two cups of coffee.
MICHAEL PHELPS' DIET
Breakfast: Three fried egg sandwiches; cheese; tomatoes; lettuce; fried onions; mayonnaise; three chocolate-chip pancakes; five-egg omelette; three sugar-coated slices of French toast; bowl of grits; two cups of coffee
Lunch: Half-kilogram (one pound) of enriched pasta; two large ham and cheese sandwiches with mayonnaise on white bread; energy drinks
Dinner: Half-kilogram of pasta, with carbonara sauce; large pizza; energy drinks
For lunch: half a kilogram (one pound) of enriched pasta; two large ham and cheese sandwiches on white bread smothered with mayonnaise, washed down by energy drinks.
For dinner: Another half-kilogram of pasta, perhaps with a carbonara sauce, followed by a large pizza and more energy drinks.
That combination may not sound very healthy, and at a staggering 10,000 calories, would feed five average men for a day.
But the menu is reportedly all in a training day's eating for champion swimmer Michael Phelps, who won six gold medals in the 2004 Athens Olympics and is aiming for eight this time round.
"Eat, sleep and swim, that's all I can do," said the US swimmer, after winning his 11th Olympic gold.
Judging by the amount he eats and swims, that is not altogether surprising.
Fruit and veg
Even though the 23-year-old spends a solid five hours of each day burning off those calories, the diet still seems excessive. Is he following some sort of dietician guru's programme?
Barbara Lewin, a nutritionist who has advised international athletes on their dietary health for almost two decades, thinks not.
A light snack for a record-breaking Olympian swimmer?
"Health-wise, if he were eating like this long-term, he'd probably be having to see a cardiologist regularly," Mrs Lewin told the BBC.
She recommended cutting out the egg yolks, replacing the white bread with whole-wheat, throwing some fruit and vegetables into the mix, and spreading the food out over the day with regular snacking.
But while the quality of the calories consumed by the six-foot four-inch (1.93m) swimmer may not seem healthy, Ms Lewin suggested there are good reasons behind Mr Phelps' diet.
"I've worked with more than 1,000 endurance athletes - swimmers and runners - and one of the most common problems they have is glycogen depletion - the result of not getting enough carbohydrates," she said.
"Nine out of 10 times the reason an athlete doesn't reach their personal best is because they're not getting enough carbohydrates and that's what your muscles need for food."
Phelps won his sixth gold medal in Beijing in the 200m medley on Friday, and will be aiming to equal fellow American Mark Spitz's record of winning seven gold medals in a single Olympic games when he takes to the pool for Saturday's 100m fly.
He will break Spitz's 36-year record if his team qualify, and go on to win, Sunday's 4x100m relay.
The very process of challenging that record entails a hectic schedule of heats, semi-finals and finals.
Between winning his 10th gold medal in the 200m butterfly - which made him history's most successful Olympian - and his 11th in the men's 4x200m relay, Phelps had just an hour between races.
With that kind of turn-around, topping up his carbohydrate count is key, Ms Lewin suggested. The copious amount of refined carbohydrates consumed in the bread and pasta he eats will digest quickly and give the swimmer instant energy.
Phelps, who weighs around 85kg (187lbs), understands this. Asked what was needed to continue his gold-medal winning streak, he said simply: "Get some calories into my system and try to recover the best I can."
Keeping his carbohydrates topped up between races, said Ms Lewin, is important for avoiding what athletes call "hitting the wall" - that stage in an endurance competition when the body has used up all its carbohydrate fuel (sometimes known as muscle glycogen) and instead starts the much less efficient process of burning fat for energy.
The Phelps diet is not recommended for everyone. Due to his muscle-intensive physique, the swimmer's metabolism - the process of converting food into energy - far exceeds that of a more average man, said Jeff Kotterman, director of the US National Association of Sports Nutrition.
"It's a combination of peak performance coupled with the fact that he has an enormous metabolism - he burns more calories sitting at a desk than a lot of people burn walking," Mr Kotterman told the BBC.
He suggested Phelps, with an estimated 8% body fat, probably burns 1,000 calories per hour during his swimming training, compared to the equivalent exercise for an average person - vigorous walking - that would burn between 170 and 240 calories.
Consequently, trying to emulate the Phelps diet by consuming up to 12,000 calories a day in order to attain his physique would more than likely come to a wobbly end.
One pound of fat has roughly 3,500 calories, so an ordinary man could put on almost three pounds of fat a day.
But then again, Michael Phelps - who has now won the 400m medley, 200m freestyle, 200m butterfly, 4x100m free relay, 4x200m free relay and the 200m medley in world record times - is clearly no ordinary man.