title: The effects of two different hypocaloric diets on glucagon-like peptide 1 in obese adults, relation with insulin response after weight loss.
abstract: OBJECTIVE
  Few studies have investigated the effect of type of diets on GLP-1 concentrations. The aim of this study was to compare the effect of two diets on circulating GLP-1 levels and the relation with insulin response after weight loss.
  
  
  METHODS
  A population of 118 obese patients were analyzed. Patients were randomly allocated to two groups: (a) Diet I (low carbohydrate) and (b) Diet II (low fat). Biochemical and anthropometric parameters were measured before and after 3 months of hypocaloric diet.
  
  
  RESULTS
  Fifty-two patients (12 male/40 female) were treated with Diet I and 66 patients (21 male/45 female) with Diet II. In Group I, basal GLP-1 levels did not change after dietary treatment (9.4+/-3.3 vs. 9.9+/-3.1 ng/ml; ns). In Group II, GLP-1 levels decreased significantly (8.4%) (9.2+/-3.3 vs 8.7+/-3.1 ng/ml; P<.05). In the multivariate analysis with a dependent variable (levels of GLP-1), only insulin levels remained as an independent predictor in the model (F=5.9; P<.05), with an increase of 0.6 ng/ml (95% CI 0.1-1.1) GLP-1 concentrations with each increase of 1 mUI/ml of insulin.
  
  
  CONCLUSIONS
  A hypocaloric diet with a low fat percentage decreased GLP-1 levels with a direct correlation with insulin levels. Nevertheless, patients with a hypocaloric diet with a low carbohydrate percentage treatment did not change GLP-1 levels. Diet macronutrient manipulation on GLP-1 response could be useful in an obesity nutrition therapy.
authors.affiliation: Institute of Endocrinology and Nutrition, Medicine School and Unit of Investigation, Hospital Rio Hortega, University of Valladolid, Valladolid, Spain. dadluis@yahoo.es
authors.forename: Daniel A
authors.initials: DA
authors.lastname: de Luis
authors.forename: Manuel Gonzalez
authors.initials: MG
authors.lastname: Sagrado
authors.forename: Rosa
authors.initials: R
authors.lastname: Conde
authors.forename: Rocio
authors.initials: R
authors.lastname: Aller
authors.forename: Olatz
authors.initials: O
authors.lastname: Izaola
mesh_terms: D000328:Adult; D015992:Body Mass Index; D050528:Diet, Carbohydrate-Restricted; D018752:Diet, Fat-Restricted; D002149:Energy Intake; D005260:Female; D052216:Glucagon-Like Peptide 1 / Q000097:blood*; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009765:Obesity / Q000097:blood* / Q000628:therapy*; D011446:Prospective Studies; D015431:Weight Loss / Q000502:physiology*
chemical_list: D007328:Insulin; D052216:Glucagon-Like Peptide 1