title: Viscosity of fiber preloads affects food intake in adolescents.
abstract: OBJECTIVE
  Dietary fiber that develops viscosity in the gastrointestinal tract is capable of addressing various aspects of food intake control. The aim of this study was to assess subsequent food intake and appetite in relation to the level of viscosity following three liquid preloads each containing 5 g of either a high (novel viscous polysaccharide; NVP), medium (glucomannan; GLM), or low (cellulose; CE) viscosity fiber.
  
  
  RESULTS
  In this double-blind, randomized, controlled and crossover trial, 31 healthy weight adolescents (25 F:6 M; age 16.1+/-0.6 years; BMI 22.2+/-3.7 kg/m(2)) consumed one of the three preloads 90 min prior to an ad libitum pizza meal. Preloads were identical in taste, appearance, nutrient content and quantity of fiber, but different in their viscosities (10, 410, and 700 poise for CE, GLM, and NVP, respectively). Pizza intake was significantly lower (p=0.008) after consumption of the high-viscosity NVP (278+/-111 g) compared to the medium-viscosity GLM (313+/-123 g) and low-viscosity CE (316+/-138 g) preloads, with no difference between the GLM and CE preloads. Appetite scores, physical symptoms and 24-h intake did not differ among treatment groups.
  
  
  CONCLUSIONS
  A highly viscous NVP preload leads to reduced subsequent food intake, in terms of both gram weight and calories, in healthy weight adolescents. This study provides preliminary evidence of an independent contribution of viscosity on food intake and may form a basis for further studies on factors influencing food intake in adolescents.
authors.affiliation: Department of Nutritional Sciences, Faculty of Medicine, University of Toronto, Toronto, Ontario, Canada. v.vuksan@utoronto.ca
authors.forename: V
authors.initials: V
authors.lastname: Vuksan
authors.forename: S
authors.initials: S
authors.lastname: Panahi
authors.forename: M
authors.initials: M
authors.lastname: Lyon
authors.forename: A L
authors.initials: AL
authors.lastname: Rogovik
authors.forename: A L
authors.initials: AL
authors.lastname: Jenkins
authors.forename: L A
authors.initials: LA
authors.lastname: Leiter
mesh_terms: D000293:Adolescent; D001066:Appetite / Q000187:drug effects; D015992:Body Mass Index; D002482:Cellulose / Q000009:adverse effects / Q000494:pharmacology; D018592:Cross-Over Studies; D004032:Diet; D015930:Diet Records; D004043:Dietary Fiber / Q000009:adverse effects / Q000494:pharmacology*; D004311:Double-Blind Method; D004435:Eating / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D008351:Mannans / Q000009:adverse effects / Q000494:pharmacology; D011134:Polysaccharides / Q000009:adverse effects / Q000494:pharmacology; D011795:Surveys and Questionnaires; D014783:Viscosity
chemical_list: D004043:Dietary Fiber; D008351:Mannans; D011134:Polysaccharides; C022901:(1-6)-alpha-glucomannan; D002482:Cellulose