Table 1.

Modified King's Obesity Staging Criteria⁹

	Stage 0 ‘Normal health’	Stage 1 ‘At risk of disease’	Stage 2 ‘Established disease’	Stage 3 ‘Advanced disease’
Airways	Normal	Snoring	Required CPAP	Cor pulmonale
Body mass index	<35	35–40	40–60	>60
Cardiovascular	<10% risk	10–20% risk	Heart disease	Heart failure
Diabetes	Normal	Impaired fasting glucose	Type 2 diabetes	Uncontrolled type 2 diabetes
Economic	Normal	Expensive travel/clothes	Workplace discrimination	Unemployed due to obesity
Functional	Can manage three flights of stairs	Manages one or two flights of stairs	Requires walking aids or wheelchair	Housebound
Gonadal	Normal	PCOS	Infertility	Sexual dysfunction
Health perceived	Normal	Low mood or QoL	Depression or poor QoL	Severe depression
Body image	Normal	Dislikes body	Body image dysphoria	Eating disorder with purging (drug use or vomiting)

CPAP = continuous positive airway pressure; PCOS = polycystic ovary syndrome; QoL = quality of life.