Anti-obesity medicines: here are the guidelines from doctors and dietitians on how to use them correctly

The psychological aspect is no less important. Whilst it is true that GLP-1 medications are associated with an improvement in mental wellbeing, many people with obesity already have pre-existing psychological vulnerabilities, and the profound changes to their sense of self associated with significant weight loss can cause these to resurface. The Consensus therefore recommends that, before starting treatment, a psychologist should assess the presence of any mental health issues, including alcohol use.

Exercise also plays a role that experts wish to emphasise: any form of physical activity helps with weight loss, prevents weight regain and protects general health, but it is strength training (or ‘resistance training’), combined with aerobic exercise, that is the key to limiting the loss of lean body mass during treatment.

The document does not limit itself to the clinical aspects of obesity treatment, but also highlights the inequalities that risk turning into discrimination. Obesity affects ethnic minorities and those from lower socio-economic backgrounds the hardest – the very same groups that also have less access to these expensive medicines.

There is also a cultural issue, even before the economic one: people with obesity who have no other related conditions are often treated as ‘lower priority’ cases compared to those who have already developed complications; a sign that the stigma surrounding obesity – a condition that should be treated in its own right as a ‘disease’, and not only when it causes complications – is far from being overcome. The authors call for policies that expand coverage of these treatments and clinical services, and that ensure access to a dietitian for other members of the multidisciplinary team, in order to reduce inequalities in access to care.

What makes the issue even more pressing is a finding that emerges from a review of 417 randomised studies on incretin-based therapies: fewer than 20 per cent collected data on dietary habits or nutritional markers, and fewer than 5 per cent measured outcomes relating to bone health, micronutrients or physical function. In short, science knows full well how many kilos these drugs help people lose, but it still knows far too little about what actually happens to the bodies of those who take them in the long term.

For this reason, the authors of the Consensus call for future clinical trials to always include a set of key assessments (core outcome set), such as monitoring nutritional safety, assessing muscle function and mobility, determining optimal protein intake, psychological outcomes, and dose-titration strategies to reduce treatment discontinuation due to gastrointestinal disturbances, as well as ad hoc research to assess what happens upon discontinuation of treatment or following bariatric surgery.

The take-home message of the Consensus is clear: incretin-based therapies represent a genuine paradigm shift in the treatment of obesity, but to be used to their full potential they must be combined with a diet supervised by a dietitian (with constant attention to protein, fibre and fluids), resistance training and psychological support, to safeguard mental health. In short, the medication is just one part of the treatment: without the others, there is a risk of winning the battle on the scales but losing the real war – that of long-term health.