Some factors related to obesity in the Japanese sumo wrestler.

Sumo is an ancient sport in Japan and there are at present over 800 professional sumo wrestlers (rikishis). After entrance into the wrestler society a wrestler takes strenuous daily training together with a very high calorie diet (more than 5,000 cal). Frequency of food intake is twice a day. The average diet of Japanese people contains of 2,279 calories and the meal frequency is generally three times a day. In 96 wrestlers average actual body weight and modified Broca index was 100.4 kg and 143.5%, respectively. In this group the prevalence of overweight with obesity, overweight without obesity, nonoverweight with obesity, and nonoverweight without obesity was 53.4, 39.1, 1.0, and 6.5%, respectively. Also mean serum levels of triglyceride, phospholipid, uric acid, and total protein were significantly higher than those obtained in 89 age-matched healthy males. The incidence of diabetes mellitus, gout, and hypertension in wrestlers was 5.2, 6.3, and 8.3%, respectively, all values being considerably higher than in controls. Weight correlated significantly with skinfold thickness, diastolic blood pressure, total cholesterol, and uric acid in each group. Multiple regression analyses were made treating weight or uric acid as dependent variables in both groups. Obesity, hyperlipidemia, and hyperuricemia in wrestlers were presumed to be caused chiefly by the high calorie diet and partially by the infrequent meal intake.