26/04/2026
**GLP-1 Agonists for Weight Loss: A Dietitian's Perspective**
There has been a significant trend in recent years involving the use of GLP-1 agonists, a class of injectable medications, for weight loss. While various formulations have entered the market, their fundamental role is to suppress appetite, which, when successful, leads to reduced food intake and subsequent weight loss.
However, the use of these medications without concurrent dietetic supervision presents considerable risks. When a person's nutritional adequacy is not assessed and guided by a dietitian, a significant portion of the weight lost may come from lean muscle mass and body fluids, not just fat. This can lead to exhaustion and a decrease in the person's metabolic rate as the body attempts to adapt. Consequently, weight loss often plateaus, leaving the individual in a state similar to that following an extreme diet: an exhausted body with potential nutritional deficiencies and reduced muscle mass, without having learned sustainable, healthy eating habits.
For weight loss efforts to be successful and maintainable, they must be integrated with comprehensive lifestyle changes. This includes improving dietary habits, often by adopting principles of the Mediterranean diet, incorporating a wider variety of nutritious foods, and integrating regular physical exercise into one's routine.
The risks associated with GLP-1 agonists vary significantly with age. In younger individuals, while they may tolerate the treatment, there is a high likelihood of regaining the weight once the medication is ceased, thus perpetuating a cycle of weight fluctuation. For individuals over the age of 65, the use of these medications can be particularly hazardous. This demographic is already susceptible to age-related sarcopenia and loss of bone density. The rapid weight loss induced by these drugs can exacerbate these conditions, potentially leading to severe health consequences. Malnutrition in this age group can, in some cases, be fatal.
It is imperative that prescribing practitioners, typically general practitioners, refer patients to a dietitian when initiating treatment with a GLP-1 agonist. This ensures the patient receives guidance on crucial lifestyle modifications. For older adults, the decision to prescribe should be made with extreme caution, and the need for dietetic supervision is paramount.
Effective management requires ongoing scientific monitoring, including regular body composition analysis, to ensure that weight loss is primarily from fat mass and that muscle mass is preserved.
Unfortunately, the current landscape is often influenced more by commercial interests than by best practice principles. The promotion of these drugs can sometimes prioritise sales over their correct and safe application.
From a dietetic standpoint, I do occasionally recommend these injections as a tool for patients I am closely monitoring, particularly those who have reached an impasse in their weight loss journey. In these specific cases, a GLP-1 agonist can provide temporary support, acting as a bridge while the patient works on establishing lasting behavioural and lifestyle changes. Used in this manner, as part of a structured, supervised program, these medications can be a valuable tool.
