title: A high-glycemic index, low-fiber breakfast affects the postprandial plasma glucose, insulin, and ghrelin responses of patients with type 2 diabetes in a randomized clinical trial.
abstract: BACKGROUND
  Meals with a low glycemic index (GI) and rich in fiber could be beneficial with regard to postprandial metabolic profile and satiety.
  
  
  OBJECTIVE
  The aim of this study was to investigate the effect of 4 breakfasts with a different GI and amount of fiber on postprandial plasma glucose, insulin, and appetite in patients with type 2 diabetes.
  
  
  METHODS
  This randomized 4-intervention crossover trial included 14 patients [7 men; ages 65.8 ± 5.2 y; glycated hemoglobin: 6.6 ± 0.9%; BMI (in kg/m(2)): 27.2 ± 3.1]. Dietary interventions were as follows: breakfasts with a high GI (60.4 ± 0.1%) and high fiber (6.0 ± 0.3 g) (HGI-HF), a high GI (60.9 ± 1.7%) and low fiber (2.5 ± 0.4 g) (HGI-LF), a low GI (37.7 ± 0.1%) and high fiber (6.2 ± 0.3 g) (LGI-HF), and a low GI (39.8 ± 1.3%) and low fiber (2.0 ± 0.1 g) (LGI-LF). Plasma glucose, insulin, and total ghrelin were evaluated postprandially (0-180 min). A visual analog scale was used to assess appetite. Data were analyzed by generalized estimating equations and post hoc least significant difference (LSD) tests. Data are reported as means ± SDs.
  
  
  RESULTS
  The area under the curve (AUC) [mean (95% CI); P for LSD tests] for plasma glucose (mmol/L × min) was higher after patients consumed the HGI-LF breakfast [9.62 (8.39, 10.84)] than after the LGI-HF breakfast [8.95 (7.71, 10.18)] (P ≤ 0.05). Insulin AUC (μIU/mL × min) after patients consumed the HGI-LF meal [65.72 (38.24, 93.19)] was higher than after the HGI-HF meal [57.24 (32.44, 82.04)] (P ≤ 0.05). The other observed difference was higher insulin AUC after the consumption of the LGI-LF breakfast [61.54 (36.61, 86.48)] compared with the AUC after the LGI-HF breakfast [54.16 (31.43, 76.88)] (P ≤ 0.05). Plasma ghrelin decreased in comparison with baseline only after patients consumed the LGI-HF and LGI-LF breakfasts (P ≤ 0.05). Subjective satiety did not differ between breakfasts.
  
  
  CONCLUSIONS
  Plasma glucose, insulin, and ghrelin responses were least favorable when patients with type 2 diabetes consumed a breakfast with a high GI and low fiber, which suggests that reducing the GI or increasing the fiber content or both of breakfasts may be a useful strategy to improve the postprandial metabolic profile of these patients. This trial was registered at clinicaltrials.gov as NCT01410292.
authors.affiliation: Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Flávia M
authors.initials: FM
authors.lastname: Silva
authors.affiliation: Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Caroline K
authors.initials: CK
authors.lastname: Kramer
authors.affiliation: Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil.
authors.forename: Daisy
authors.initials: D
authors.lastname: Crispim
authors.affiliation: Endocrine Division, Hospital de Clínicas de Porto Alegre, Federal University of Rio Grande do Sul, Porto Alegre, Brazil mirelajobimazevedo@gmail.com.
authors.forename: Mirela J
authors.initials: MJ
authors.lastname: Azevedo
mesh_terms: D000368:Aged; D001066:Appetite; D001786:Blood Glucose / Q000378:metabolism*; D062408:Breakfast; D018592:Cross-Over Studies; D003924:Diabetes Mellitus, Type 2 / Q000178:diet therapy*; D004043:Dietary Fiber / Q000008:administration & dosage*; D005260:Female; D054439:Ghrelin / Q000097:blood*; D038321:Glycemic Index; D006801:Humans; D007328:Insulin / Q000097:blood*; D008297:Male; D008875:Middle Aged; D015596:Nutrition Assessment; D019518:Postprandial Period; D012527:Satiation / Q000502:physiology
chemical_list: D001786:Blood Glucose; D004043:Dietary Fiber; D054439:Ghrelin; D007328:Insulin
keywords: diabetes; dietary fiber; glycemic index; plasma ghrelin; plasma glucose