Lund University is celebrating 350 years.


Javascript is not activated in your browser. This website needs javascript activated to work properly.

Roux-en-Y gastric bypass versus calorie restriction: support for surgery as the direct contributor to aloncltered responses of insulin and incretins to a mixed meal

  • Andreas Lindqvist
  • Jan Hedenbro
  • Leif Groop
  • Nils Wierup
Publishing year: 2017
Language: English
Pages: 234-242
Publication/Series: Surgery for Obesity and Related Diseases
Volume: 13
Issue: 2
Document type: Journal article
Publisher: Elsevier

Abstract english



To study the immediate effects of Roux-en-Y gastric bypass (RYGB) on glucose homeostasis, insulin, and incretin responses to mixed-meal tests compared with the effects of calorie restriction (CR).


University-affiliated bariatric surgery clinic.


RYGB induces remission of type 2 diabetes (T2 D) long before significant weight loss occurs. The time course and underlying mechanisms of this remission remain enigmatic. A prevailing theory is that secretory patterns of incretin hormones are altered due to rearrangement of the gastrointestinal tract. To what extent reduced calorie intake contributes to the remission of T2 D is unknown.


Nine normoglycemic patients and 10 T2 D patients were subjected to mixed-meal tests (MMT) 4 weeks before surgery before initiation of a very low calorie diet regimen (MMT-4 w), 1 day before surgery on a very low calorie diet regimen (MMT-1 d), on the morning of the first day after surgery (MMT+1 d; first postsurgical meal), and 6 weeks after surgery (MMT+6 w). Insulin, glucose, active glucagon-like peptide 1 (GLP-1), and glucose-dependent insulinotropic polypeptide (GIP) were measured.


CR lowered insulin in T2 D patients, whereas glucose, GIP, and GLP-1 were unaffected. RYGB immediately increased plasma insulin and GIP. The GLP-1 response was delayed compared with the GIP response. T2 D patients exhibited lower insulin responses after RYGB compared with normoglycemic patients. GIP responses were similar in both groups at all occasions, whereas T2 D patients displayed markedly elevated GLP-1 responses 6 weeks after RYGB. Glucose was unaffected by CR and RYGB in both groups. Insulin sensitivity was unaffected by CR but improved with RYGB.


RYGB exerts powerful and immediate effects on insulin and incretin responses to food, independently of changes caused by CR.


  • Endocrinology and Diabetes
  • Bariatric surgery
  • gastric bypass
  • incretins
  • calorie restriction


  • Neuroendocrine Cell Biology
  • Diabetes and Endocrinology
  • ISSN: 1550-7289

Lund University Diabetes Centre, CRC, SUS Malmö, Entrance 72, House 91:12. SE-205 02 Malmö. Telephone: +46 40 39 10 00