World Obesity Day: let's talk about it!

So diets alone would not be sufficient in this fight against obesity?

Maya Gianadda: In fact, overly strict, restrictive diets often cause uncontrolled deficiencies and frustration. When a normal diet is resumed, weight is regained, often more than before the restrictive diet. The body, even an obese one, deprived of nutrients, «paradoxically» slows down its metabolism to rebuild reserves.

This results in a «yo-yo effect» that leads to a long-term increase in weight. In the end, we see that restrictive dieting is a good way to gain weight. For many years, therapists were not aware of this fact. The manufacturers who sell the diets continue to ignore it, but to their advantage.

A behavioural approach that aims to eat a balanced diet without deprivation and without causing guilt, by focusing on improving habits in the long term, should be favoured.

You talk about readjusting hunger regulation. How?

Dr Raffaela Morard Passera: The best long-term treatment for readjusting hunger regulation is metabolic surgery. The procedures most commonly performed in Switzerland, such as gastric bypass and sleeve gastrectomy, are reserved for body mass indexes >35kg/m2 with one or more comorbidities. These are surgical procedures that affect the anatomy of the digestive tract, enabling long-term self-regulation. Patients then lose weight without feeling hungry. During this period, the patient is able to relearn how to eat healthily. These beneficial effects result from a regulation of the hormones in the digestive tract that control hunger and satiety. These same hormones help regulate blood sugar. Surgical procedures to treat obesity are therefore also effective in treating and achieving remissions of type 2 diabetes. Obesity surgery is currently the most effective way to achieve significant and lasting weight loss.

You mentioned new drugs. How do they work?

Dr Raffaela Morard Passera: The new drugs act on the same cellular receptors as the hormones that are modulated by obesity surgery. The effect is therefore similar in that it regulates feelings of fullness and hunger. These GLP-1 receptor agonist drugs must be injected on a weekly basis.

Both surgery and medication therefore enable hunger to be regulated, resulting in weight loss. Which treatment should be chosen?

Dr Raffaela Morard Passera: This choice must clearly be adapted to the very different desires and situations of each patient. The experience of an interdisciplinary team should point the way forward. As obesity is a chronic disease, a sequential approach is increasingly considered. In other words, it is likely that a large proportion of obese patients will eventually have benefited from both of these therapeutic options in the course of their lives. More importantly, it should be remembered that these two therapeutic options must be combined with a long-term dietary and behavioural approach. Lasting weight loss cannot be achieved without changing certain habits that run counter to the recommendations.

While surgery allows for long-term regulation, medication leads to weight regain when it is stopped.

How is the care of obese patients organised?

Maya Gianadda: In Switzerland, centres of expertise bring together the specialists needed for an interdisciplinary approach to obesity. Coordination is carried out by the SMOB (Swiss Society for the Study of Morbid Obesity and Metabolic Disorders), which acts as an intermediary between the authorities and therapists.

In Valais, the Centre de la Clinique de Valère is celebrating its 15th anniversary in 2025. During this period, we have treated more than 1'000 patients. 800 of them have undergone obesity surgery, with the introduction of robotic surgery in recent years. Some 200 patients have benefited from drug treatment. This treatment with GLP-1 analogues has accelerated over the last two years, particularly with the arrival of semaglutide on the market. We place particular emphasis on the need for regular long-term monitoring of our patients.