Nutritional, Functional and Psychological Considerations for Incretin-Based Therapies in Adults

Hi, I'm Dr. Laurence Dobbie . I work as an academic clinical fellow in general practice at King's College London with a clinical and academic interest in obesity medicine. In question-based therapies, including GLP-1 receptor agonists, have transformed obesity management. However, medication alone is not enough. These therapies profoundly affect appetite, food intake, body composition, and even psychological well-being. In this five-minute CPD, I'll summarize key clinical messages from the IASO consensus statement on nutritional, functional, and psychological considerations during treatment with incretin-based therapies in adults.

Incretin-based therapies like semaglutide and terzepatide act through gut-brain pathways involved in appetite regulation. They increase satiety, reduce hunger, slow gastric emptying, and lower daily energy intake by several hundred calories per day. Clinical trials show an average weight loss of around 15% with semaglutide and over 20% with terzepatide when combined with behavioural support. And beyond weight loss, these medications reduce cardiovascular events, kidney disease progression and improve conditions such as sleep apnea and heart failure with preserved ejection fraction. But despite these benefits, fewer than half of people remain on treatment long term. Cost, side effects and lack of support all contribute to this. This is why multidisciplinary management is essential. Medical nutrition therapy delivered by a registered dietician is a cornerstone of safe and effective obesity management. Appetite suppression often leads to unintentional under eating and without guidance this could result in inadequate protein and micronutrient intake. Dieticians help patients maintain dietary quality during reduced appetite.

They support medication adherence, manage gastrointestinal side effects, and reduce the risk of disordered eating. Evidence shows that dietitian-led care improves cardiometabolic outcomes and supports longer-term weight maintenance in general obesity management. And as a clinician, you should consider involving a dietitian when initiating or continuing an incretin-based therapy. This is particularly relevant for patients with a higher nutritional risk, poor food intake, persistent gastrointestinal symptoms, rapid weight loss or with greater clinical complexity. People living with obesity often have pre-existing micronutrient deficiencies. Weight loss and reduced food intake can compound these risks. During weight loss, protein intake should be higher than standard adult recommendations. Expert consensus suggests aiming for 1 to 1.5 grams per kilogram of adjusted body weight per day. This helps preserve muscle mass and physical function during weight loss.

Importantly, energy intake below 1,500 calories per day increases the risk of micronutrient deficiencies, and an intake below 1,200 calories per day warrants closer monitoring and consideration of multivitamin supplementation. Annual blood tests, including a full blood count, iron studies, and vitamin B12 may be considered where appropriate, with additional tests guided by individual risk factors, clinical symptoms and local resources. And if energy intake becomes very low or symptoms of malnutrition appear, dose reduction or temporary medication pauses should be discussed using shared decision making with the patient. Weight loss includes loss of fat and lean mass and across trials about one quarter to one third of weight loss is lean mass. And loss of muscle strength may increase the risk of frailty, especially in older adults. So we should assess for functional health, not just weight.

Hand grip strength, sit-to-stand tests or simple questionnaires can identify early functional risks. And resistance exercise combined with adequate protein intake helps preserve muscle and supports weight maintenance. Bone density can reduce with weight loss. Based on limited data, this appears proportional to weight change rather than a direct obesity medication effect. So for the bones, we should ensure adequate calcium and vitamin D intake and consider fracture risk assessments in older adults or those with additional osteoporosis risk factors. Incretin-based therapies alter food reward and eating behaviours, and many people report reduced food noise and fewer cravings. This can be positive in many cases, but it can potentially also disrupt long-standing coping strategies and social routines linked to food. People living with obesity have higher rates of disordered eating. Screening should be routine before and during treatment. Weight loss can also affect identity, relationships and emotional well-being. Some individuals experience grief or anxiety despite treatment success. Stigma remains a major barrier.

Some patients feel judged for using a cretin-based therapies. Your communication matters. Use respectful, person-first language and focus on health, function and quality of life, not moral judgment. Incretin-based therapies are powerful tools, but they work best when embedded in compassionate multidisciplinary care. By addressing nutrition, physical function, and psychological well-being, clinicians can improve the safety, adherence, and long-term outcomes associated with these highly effective treatments. I am Dr. Laurence Dobbie for 5-Minute CPD. Thank you for watching. You can find additional resources on this page and further professional education at easo.org.