Kenya's Elijah Lagat has spectacularly proven that being fat is usually a result of eating too much and not exercising. Seven years ago he was told by his doctor to shed 15 kg (33 lbs) or maybe die. So Lagat began to run. From a high of 71 kg (156 lbs) in late 1992 when he was having difficulty breathing and an erratic pulse (sound familiar?), he dropped to 56 kg (123 lbs). Last week Lagat won the Boston Marathon in two hours, nine minutes, 47 seconds. Sure beats bowel irrigations and lemon juice.