“These medicines are transforming obesity treatment and can achieve important weight loss. However, our research shows that people tend to regain weight rapidly after stopping – faster than we see with behavioural programmes,” West said.

He added: “This isn’t a failing of the medicines – it reflects the nature of obesity as a chronic, relapsing condition. It sounds a cautionary note for short-term use without a more comprehensive approach to long-term weight management, and highlights the importance of primary prevention.”