tendency to be obese; obesity-prone
Medical and health context; describes a predisposition or constitutional tendency toward obesity. Often used in compounds like 肥満性糖尿病 (obesity-related diabetes).
An obesity-prone constitution is influenced by genetics.
Attention must be paid to obesity-related complications.
肥満体質 is a more colloquial term for an obesity-prone constitution, while 肥満性 is more technical.
Compound of 肥満 (obesity) + 性 (nature, tendency). The derivation is straightforward from the component kanji.