Obesity is a chronic disease. It is excess fat accumulation, an abnormal build-up of body fat, that raises the risk of adverse health outcomes. As with other chronic diseases, the definition does not require obesity-related complications to be present. The consequences are medical, and they are also social and psychological.
What this cluster asks
The definition says excess fat, so the question is how that fat accumulates and what follows. The topic can therefore be followed as five questions: how common obesity is, how excess fat is recognised and graded, why appetite control can fail, what excess fat does to the body, and how it is treated.
The five notes, in learning order
Once the question is set, each note takes one part of it.
- Obesity: Epidemiology and Prevalence: how common obesity is, how prevalence varies by sex, race, education and income, and how it has changed in adults and children, in the USA and globally.
- Obesity: Measurement and Classification: how body fat is measured directly and indirectly, and how BMI and waist circumference are interpreted and classified.
- Obesity: Neurological Basis of Appetite Control: the homeostatic and reward circuits of hunger and satiety, and the hormonal signals that act on them.
- Obesity: Complications: the diseases obesity predisposes to, and why where the fat sits matters as much as how much there is.
- Obesity: Management: treatment from lifestyle change through pharmacotherapy to bariatric surgery.
Where to start
The notes are ordered, and the first is the one that shows how widespread excess fat has become. Begin with epidemiology, then move to measurement to see how obesity is recognised at the bedside. The remaining notes move from cause (appetite control) to consequence (complications) to treatment (management). So the first thing to ask is: how widespread has obesity become?