Verification of the obesity paradox through quantitative and qualitative evaluation of fat, muscle, and bone

2023 Fiscal Year Final Research Report

• Project/Area Number: 21K11652
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 59040:Nutrition science and health science-related
• Research Institution: Hokusho University
• Principal Investigator: Okita Koichi 北翔大学, 生涯スポーツ学部, 教授 (80382539)
• Project Period (FY): 2021-04-01 – 2024-03-31
• Keywords: 肥満パラドクス / 体格指数 / 身体組成 / 身体機能 / 健康寿命 / 生活習慣病 / サルコペニア / フレイル

Outline of Final Research Achievements

The obesity paradox means that although obesity is a risk factor for lifestyle-related diseases and heart disease, among chronically ill and elderly people, those with a high body mass index who are considered obese have a higher survival rate, while those who are thin have a lower survival rate. In this study, we hypothesized that this paradox involves the influence of skeletal muscle and bone, which contribute to body composition. We performed body composition analysis and measured the cytokines derived from muscle and bone, and examined their significance, but the quantitative and qualitative indicators of muscle and bone showed no remarkable relationship with all physical and mental health indicators related to life prognosis. We were able to present this unexpected finding at domestic and international conferences and publish it in a domestic academic journal.

Free Research Field

栄養学および健康科学関連

Academic Significance and Societal Importance of the Research Achievements

本成果は肥満パラドクスに疑義を呈するものである。肥満パラドクスは「一人歩き」し、高齢者は肥満の方が良いとの曖昧な情報が流布しているように思える。しかしながら、肥満は多くの疾患の原因となり生命予後を悪化させることは明白であり（Abdelaal M 2017）、35才以上のコホート研究では、肥満の程度と相応して死亡率が増加する（Sasazuki S 2011）。これらの研究の決定的な相異は対象者の年齢である。高齢者や疾患者の研究では既に死亡した肥満者が含まれず、生命力が強い高齢肥満者が高い生存率を示すことがその原因であるように思える。本成果は、肥満に対する正しい認識を考え直す契機になると考える。