Weight gain

Probability diagnosis

Exogenous obesity

Alcohol excess

Fluid/oedema

Drugs

Genetic polymorphisms

Serious disorders not to be missed

Cardiovascular:

• cardiac failure

Hypothalamic disorders (hyperphagia):

• craniopharyngiomas

• optic gliomas

Insulinoma

Liver failure

Nephrotic syndrome

Pitfalls (often missed)

Pregnancy (early)

Postmenopause

Endocrine disorders:

• hypothyroidism

• Cushing syndrome

• insulinoma

• acromegaly

• hypogonadism

• hyperprolactinaemia

• polycystic ovarian disease

Idiopathic oedema syndrome

Klinefelter syndrome

Congenital disorders:

• Prader–Willi syndrome

• Laurence–Moon–Biedl syndrome

Masquerades checklist

Depression

Drugs (e.g. OCP, steroids, pizotifen, sulphonylureas, insulin)

Thyroid disorder (hypothyroidism) and other endocrine (as above)

Is the patient trying to tell me something?

Yes: the reasons for obesity should be explored.

Key history

Ascertain food and beverage intake including typical daily meals. Exercise, drug, psychological and family history.

Key examination

• Measure body weight and height and calculate BMI, waist circumference, waist–hip circumference, upper arm circumference

• Assess the degree and distribution of body fat and the overall nutritional status

• Search for evidence of diabetes, atherosclerosis, hypothyroidism, Cushing syndrome and signs of alcohol abuse

Key investigations

These are more appropriate if patient unwell:

• anthropometric measurements as above, especially BMI and waist circumference

• FBE

• blood lipids

• glucose (fasting)

• LFTs

• U&E

Consider TFTs, serum cortisol, ECG and CXR.

Diagnostic tips

• The onset of obesity can occur at any age.

• Abdominal obesity gives a higher cardiovascular risk at any rate.

• Ask the patient what they believe is the cause of their weight gain/obesity.