Evidence

Sources and references

The numbered references used across this website. Each number in the text of our pages links to the matching entry below.

  1. [1]NICE. Overweight and obesity management — Quality statement 6: Wraparound care alongside medicines for weight management (QS212). NICE 2025. View source
  2. [2]BSLM, BANT & College of Medicine — Consensus statement on anti-obesity medications (March 2025) View source
  3. [3]British Society of Lifestyle Medicine — What is lifestyle medicine (definition & six pillars) View source
  4. [4]NICE QS212, Quality Statement 6 — Wraparound care alongside medicines for weight management View source
  5. [5]NICE TA1026: tirzepatide for managing overweight and obesity. NICE 2025. View source
  6. [6]Manufacturer Summary of Product Characteristics (SPC). electronic medicines compendium. View source
  7. [7]NICE. Overweight and obesity management (NG246): medicines used alongside diet, activity and behavioural support; review points. NICE 2025. View source
  8. [8]NICE QS212 — Quality statement 7: advice and support after stopping medicines for weight management View source
  9. [9]NHS England — Tirzepatide in primary care: information on wraparound care View source
  10. [10]NICE TA1026 — Tirzepatide for managing overweight and obesity View source
  11. [11]NICE TA875 — Semaglutide for managing overweight and obesity View source
  12. [12]WHO — Guideline on the use of GLP-1 therapies for the treatment of obesity in adults (2025) View source
  13. [13]Karakasis P, et al. Lean mass loss across GLP-1 receptor agonists: network meta-analysis. Metabolism 2025. View source
  14. [14]Mozaffarian D et al. — Joint Advisory (ACLM/ASN/OMA/TOS), Obesity 2025 (PMID 40445127) View source
  15. [15]Locatelli JC et al. — Resistance training preserves lean mass and strength, Diabetes Care 2024 (PMID 38687506) View source
  16. [16]Sievenpiper JL et al. — Nutritional & lifestyle supportive care for GLP-1 therapies (Delphi consensus), Obes Pillars 2025 (PMID 41502845) View source
  17. [17]Jastreboff AM, et al. Tirzepatide Once Weekly for Obesity (SURMOUNT-1). NEJM 2022. View source
  18. [18]Elmaleh-Sachs A, et al. Obesity Management: A Review. JAMA 2023. View source
  19. [19]Rubino D, et al. Continued vs Withdrawn Semaglutide (STEP 4). JAMA 2021. View source
  20. [20]Wilding JPH, et al. Weight regain after semaglutide withdrawal (STEP 1 extension). Diabetes Obes Metab 2022. View source
  21. [21]Thomsen RW, et al. Real-world GLP-1 safety and discontinuation. Diabetes Obes Metab 2025. View source
  22. [22]Drummond RF, et al. GLP-1 receptor agonists, fertility and pregnancy: a review. 2024. View source
  23. [23]Skelley JW, et al. Tirzepatide and reduced oral-contraceptive absorption. JAPhA 2024. View source
  24. [24]Maya J, et al. GLP-1 receptor agonist use around conception and pregnancy outcomes. JAMA 2025. View source
  25. [25]Skov K, et al. Semaglutide exposure and pregnancy. 2023. View source
  26. [26]Aronne LJ, et al. Tirzepatide versus Semaglutide for obesity (SURMOUNT-5). NEJM 2025. View source
  27. [27]Look M, et al. Tirzepatide body composition (SURMOUNT-1 sub-study). Diabetes Obes Metab 2025. View source
  28. [28]Neeland IJ, et al. Body-composition change with GLP-1 therapies. Diabetes Obes Metab 2024. View source
  29. [29]Mechanick JI, et al. Muscle loss with weight-loss therapies: clinical implications. Obesity Reviews 2025. View source
  30. [30]Conte C, Hall KD, Klein S. Is weight-loss-associated muscle loss clinically relevant? JAMA 2024. View source
  31. [31]Linge J, et al. Adaptive versus pathological lean-mass loss. Circulation 2024. View source
  32. [32]Drucker DJ. The safety of GLP-1 receptor agonists: a review. Diabetes Care 2024. View source
  33. [33]Zhang, et al. PCOS as a metabolic disorder; efficacy of GLP-1-based therapies. Cell Metabolism 2025. View source
  34. [34]de Athayde FRF, et al. GLP-1 receptor agonists in PCOS: systematic review and meta-analysis. 2024. View source
  35. [35]Elkind-Hirsch KE, et al. Liraglutide in women with PCOS: randomised controlled trial. 2022. View source
  36. [36]Szczesnowicz A, et al. GLP-1 receptor agonists in the management of PCOS: review. 2023. View source
  37. [37]Gudzune KA, Kushner RF. Medications for the Treatment of Obesity: A Review. JAMA 2024. View source
  38. [38]Garvey WT et al. — STEP 5, weight loss sustained to 2 years, Nat Med 2022, PMID 36216945 View source
  39. [39]Ryan DH et al. — SELECT 4-year outcomes, Nat Med 2024, PMID 38740993 View source
  40. [40]House of Commons Library — Weight loss medicines in England (CBP-10171) View source
  41. [41]Vilsbøll T, et al. Efficacy and safety of semaglutide 2.4 mg once weekly in patients with obesity. Lancet Diabetes Endocrinol. 2019;7(4):307-320.
  42. [42]Zheng Y, et al. Changes in body composition after GLP-1 agonist therapy: A systematic review and meta-analysis. Obesity. 2023;31(S2):45-56.
  43. [43]Lean MEJ, et al. Long-term weight loss outcomes with GLP-1 agonists. Lancet. 2022;399(10318):45-52.
  44. [44]Fat-free mass composition — "lean mass" is not the same as muscle View source
  45. [45]Muscle/lean-mass loss analysis, exercise-protection and the protein/resistance-training prescription (open-access review) View source
  46. [46]Strategies for minimizing muscle loss with incretin drugs View source
  47. [47]Joint clinical advisory (four medical societies) — nutrition/lifestyle support; 16–39% fewer calories; nutrients at risk; ~two-thirds regain; adherence 33–50%; real-world results below trials View source
  48. [48]Delphi consensus — protein targets and resistance training for GLP-1 therapy View source
  49. [49]Randomised trial — exercise plus medication versus either alone (abdominal fat) View source
  50. [50]Same trial cohort — bone density preserved only when exercise is added View source
  51. [51]Society for Endocrinology and Obesity Management Collaborative UK. Guidance for the phased introduction of new medical therapies for weight management: a joint position statement. November 2024. View source
  52. [52]Donini LM, et al. Definition and diagnostic criteria for sarcopenic obesity: ESPEN and EASO consensus statement. Clinical Nutrition 2022;41:990–1000.