obesity       
noun [ U ] uk/əʊˈbiː.sə.ti/ us/oʊˈbiː.sə.t̬i/
C1 肥胖
the fact of being extremely fat, in a way that is dangerous for health
  The National Institute of Health is discussing ways of tackling the problem of childhood obesity. 国立卫生研究院正在讨论应对儿童肥胖问题的方法。 
 A diet that is high in fat and sugar can lead to obesity. 高脂肪和高塘饮食会导致肥胖症。