Body composition and resting metabolic rate of Japanese college Sumo wrestlers and non-athlete students: are Sumo wrestlers obese?

Abstract

The body mass index [BMI = body weight/height 2 (kg/m2 )] is widely used as an indicator of obesity. However, BMI is not the best way to assess obesity, because obesity is an excess of body fat, not body weight. The difference between obesity assessments based on BMI and those based on the percentage of body fat (%Fat) causes problems in evaluating extraordinarily large people, such as Sumo wrestlers, who have both a large fat mass and a large muscle mass. We assessed obesity in male college Sumo wrestlers (n = 15) and non-athlete students (n = 20) using BMI and %Fat as reference indices. Anthropometric parameters and resting metabolic rate (in the sitting position) were measured. The mean body weight, BMI, and %Fat for Sumo wrestlers were 125.1 kg, 40.0, and 25.6%, respectively, which were extraordinarily high, as compared to non-athlete students (P < 0.01). All of the Sumo wrestlers were categorized as obese using the BMI criteria proposed by the World Health Organization: eight were 'severely obese' (35 £ BMI < 40) and seven were 'very severely obese' (BMI ³ 40). However, only 40% of the wrestlers (n = 6) were categorized as obese when %Fat was used as the reference (%Fat > 25%). Furthermore, the body composition chart clearly showed that some Sumo wrestlers were no more adipose than the non-athlete students. Due to their remarkable muscle development, Sumo wrestlers have an excessive fat-free mass. Thus we conclude that it is necessary to consider both BMI and %Fat to assess obesity in excessively muscular people, such as Sumo wrestlers. Furthermore, we propose new criteria and methods for documenting obesity in Sumo wrestlers based on energy metabolism that considers physical activity and dietary intake.

Quality of life, nutritional status, physical activity, and their interrelationships of elderly living on an underpopulated island in Japan

“…Anthropometric dimensions were measured following a standard protocol 8,9 . Stature was measured to the nearest 1 mm using an anthropometer (YG‐200; Yagami, Nagoya, Japan).…”

“…Anthropometric dimensions were measured following a standard protocol. 8,9 Stature was measured to the nearest 1 mm using an anthropometer (YG-200; Yagami, Nagoya, Japan). The percentage of body fat (%Fat) was determined by measuring the bioelectric impedance using a body fat analyzer (TBF-305; Tanita, Tokyo, Japan).…”

Why is low body fat rarely seen in large‐sized male athletes?

“…Given this, it appears that while energy expenditure is higher, the energy intake is also greater. For example, although no studies on physical activity levels are available for Sumo wrestlers, the predicted total energy expenditure is about 4400 kcal/day (Yamauchi, Abe, Midorikawa, & Kondo, 2004). By contrast, a study reports that Sumo wrestlers consume between approximately 4000 and 5000 kcal/ day (Midorikawa, Sakamoto, & Kondo, 2019).…”

Sumo Wrestling

“…According to relatively recent studies using the Douglas bag technique, the measured resting energy expenditure was 2952 6 302 kcal/day for 15 male college Sumo wrestlers (standing height 176.8 6 3.5 cm, body weight 125.1 6 12.9 kg) [6] and 2286 6 350 kcal/day for 10 male college Sumo wrestlers (standing height 172.9 6 8.4 cm, body weight 109.1 6 14.7 kg) [7]. However, there are a few reports about resting energy expenditure (which constitutes 60À70% of total energy expenditure) for Sumo wrestlers.…”

“…As the first major finding in Table 12.1, the average value of BMI both in professional and college Sumo wrestlers is categorized as obese using the conventional WHO criteria (i.e., BMI.30 kg/m 2 ), but the mean value of percent fat using the methods of underwater weighing, air displacement plethysmography, and dual-energy X-ray absorptiometry is less than 30%. Because of their high fat-free mass, Sumo wrestlers can be misclassified as obese based on the BMI [6]. In fact, most Sumo wrestlers are able to maintain normal serum glucose and triglyceride levels despite a very large visceral adipose tissue area (151 6 58 cm 2 ); however, daily exercise training does not reduce all cardiovascular disease risk factors such as insulin resistance [14].…”