So what is BMI? In fitness and exercise terms BMI is not a budget airline, it’s actually an acronym for Body Mass Index. To calculate your BMI you need to record your height and weight and the body mass index calculator on this site will do the rest for you.

Ok, so now I know my BMI, what now? Well for starters you BMI can be worked out by both our site and, if you’re lucky enough to have one, a Nintendo Wii Fit. But remember that this is general advice for adults only and does not apply to children.

Once you’ve worked out your BMI, remember to take into account your build and current body frame, for example if you’re an athlete, body builder, pregnant or breast feeding, your BMI may not be accurate.

If you’re over 60 then your BMI may not be accurate as when you get to this age your bones actually become lighter as you reach this age.

Simply, BMI provides a simple numeric measure of a person's "fatness" or "thinness", allowing health professionals to discuss over- and under-weight problems more objectively with their patient, and plan specific training programs geared to your targets, either bulking up, or slimming down.

"Eat, sleep and swim. That's all I can do," - Micheal Phelps. The "greatest Olympian ever" revels that he eats up to 12,000 calories a day to maintain his training! That's six times the average intake of an adult male, although when swimming 80,000 meters a week you've got to fuel that body somehow!

The swimmer starts his day with a breakfast of three fried eggs, cheese, lettuce, tomato, fried onion and mayonnaise sandwiches, a five -egg omelette, a bowl of grits (an American dish, a thick maize-based porridge) three slices of french toast and three chocolate pancakes. That's just for breakfast!

Why not check out your ideal calorie intake or monitor your nutrition data with our daily calorie counter?

Phelps has got just 3 events left and 3 potential golds to complete the 8 gold medal haul! My money's on him to do it!

Check his progress or watch the Olympic swimming online at bbc.co.uk.