Hippocrates somewhere around 400 B.C....

"Eating alone will not keep a man well: he must also take exercise. For food and exercise, while possesing opposite qualities, yet work together to produce health....and it is necessary, as it appears , to discern the power of various exercises, both natural exercises and artificial, to know which of them tends to increase flesh and which to lessen it; and not only this, but also to proportion exercise to bulk of food, to the consitution of the patient, to the age of the individual..."