Ep 99 – Assessment and management of obesity

Obesity is a medical condition characterised by excessive accumulation of body fat, to the point where it may have adverse effects on health. Its incidence is steadily rising in both young people and adults. It is typically measured using BMI, but this has limitations and may not always accurately represent the level of obesity. While genetics and hormonal factors have a role in obesity, lifestyle choices (such as diet and physical activity level) and environmental factors also significantly contribute to its development. In recent years, the prevalence of obesity has been on the rise globally, leading to serious health concerns such as increased risks of heart disease, type 2 diabetes, certain types of cancer and other health problems. In this episode, Dr Roger Henderson provides an overview of the rise of obesity, the management options we have in general practice and the impact of newer injectable drugs for weight loss that many patients are now requesting.

Key references

1. NICE. 2023. Obesity: identification, assessment and management.
2. Kelly T, et al. Int J Obes (Lond). 2008;32(9):1431-7. doi: 10.1038/ijo.2008.102.
3. NICE. 2020. Liraglutide for managing overweight and obesity.
4. NICE. 2023. Semaglutide for managing overweight and obesity.

Key take-home points

• Sixty-four percent of adults in England are currently overweight or obese (26% obese, 38% overweight). Twenty-three percent of children aged 10–11 are obese, and 20% of children over the age of 5 are overweight or obese.
• In England, around 70% of black adults, 65% of white British adults and 37% of adults of Chinese ethnicity are obese or overweight.
• Obesity is a global and complex health concern that reduces life expectancy and is a significant risk factor in multiple chronic diseases, such as type 2 diabetes, cardiovascular disease, liver disease, 12 types of cancer (it is the second biggest cause), respiratory disease and mental health.
• Britons spend more on confectionery annually (£3.9 billion) than fruit and vegetables (£2.2 billion).
• Use BMI with care: it is not a direct measure of central adiposity (caution if high muscle mass).
• People with a South Asian, Chinese, other Asian, Middle Eastern, black African or African–Caribbean family background are prone to central adiposity and their cardiometabolic risk occurs at a lower BMI, so use lower BMI thresholds as a practical measure of overweight and obesity.
• Encourage adults with a BMI below 35 kg/m² to measure their own waist-to-height ratio to assess central adiposity (the accumulation of excess fat in the abdominal area).
• When talking to a person about their waist-to-height ratio, explain that they should try to keep their waist size to half their height (so a waist-to-height ratio of under 0.5).
• Consider referral to tier 3 services if the underlying causes of overweight or obesity need to be assessed, the person has a complex disease state or needs that cannot be managed adequately in tier 2 (for example, the additional support needs of people with learning disabilities), conventional treatment has been unsuccessful, drug treatment is being considered for a person with a BMI of more than 50 kg/m² and if surgery is being considered.
• The main requirement of a dietary approach to weight loss is that total energy intake should be less than energy expenditure.
• Only consider very-low-calorie diets, as part of a multicomponent weight management strategy, for people who are living with obesity and who have a clinically assessed need to rapidly lose weight.
• Consider pharmacological treatment only after dietary, exercise and behavioural approaches have been started and evaluated.
• The co-prescribing of orlistat with other drugs aimed at weight reduction is not recommended.
• According to NICE guidance, the glucagon-like peptide 1 (GLP-1) receptor agonists liraglutide and semaglutide may be considered as injections to assist weight loss as part of a specialist weight management service.
• Semaglutide is licensed under the brand names Wegovy, Ozempic and Rybelsus; of these, only Wegovy is indicated (and recommended by NICE) for weight management, in people with or without type 2 diabetes. Ozempic and Rybelsus are indicated for the management of insufficiently controlled type 2 diabetes.
• There is now a black market in counterfeit weight loss drugs claiming to be GLP-1 receptor agonists.