Metabolic Effects of Whey Protein Supplementation After Fasting in Volunteers

Metabolic Effects of Whey Protein Supplementation After Fasting in Volunteers: A Controlled Randomized Crossover Trial

This study aims to investigate the early metabolic effects and acute phase response of an oral clear supplement containing whey protein plus carbohydrates in young healthy volunteers during fasting-induced organic response

The investigators will enroll young male healthy volunteers. In this controlled crossover clinical trial, after a 12-hour fast, subjects will be randomized to consumed either: a) 200ml of carbohydrates enriched with whey protein (CHO+WP; n=30); or b) 200ml of water plus maltodextrin (CHO group, n=30); or c) remained fasting (Fast group; n=30). Blood samples will be collected after 12h-fast and three hours after the ingestion of the supplements (or 3h fast in Fast group) for blood glucose; glycated hemoglobin; serum insulin; C-reactive protein; beta-hydroxybutyrate; triglycerides; albumin; chlorine and sodium assays. After a temporal break of seven days an inversion of the groups will performed so all subjects entered in the three groups. Group CHO+P will drink a clear non-residual supplement (698 mOsm/L) having 100% whey protein isolated from total proteins, with various vitamins (B1, B6, C, D, niacin and folic acid) with a "lemon tea" flavor (Nutren Fresh; Nestlé, São Paulo, Brazil). The formula contains no lactose or lipids; is formulated with a volume of 200ml, with a caloric density of 1.28kcal/ml; protein: 10g in 200ml of the product (100% whey protein isolate); and carbohydrate: 54g in 200ml of the product (74% glucose syrup and 26% maltodextrin); Group CHO will received a clear supplement containing 200 mL of water combined with unflavored 25 g of 100% maltodextrin (CarboCH - Prodiet, Curitiba, Brazil) at 12.5% dilution (101 mOsm/kg; 95kcal/200ml). The third group (Fast group; n=10) will not consume any food or supplement.

Male volunteers, aged between 18 and 27 years, healthy, with no report of acute illness during 3 months prior to the study will be included. Individuals with obesity (calculated body mass index above 30 kg/m2), those who reported consumption of alcoholic beverages or any nutritional supplement during the study period will be excluded. The 30 selected volunteers will be scheduled to came to the laboratory after an overnight fast of 12 hours. Participants in the fasting group will immediately collect blood samples. The CHO and the CHO+WP groups will drink 200 ml of the respective supplements described above. After an interval of three hours after ingestion of the supplement, blood samples will be collected again for biochemical assays.

After 12 hours fast participants will collect blood samples and immediately will drink an oral supplement containing carbohydrates plus whey protein. After 3 hours of ingesting the supplement blood samples will be collected again

After 12 hours fast participants will collect blood samples and immediately will drink an oral supplement containing carbohydrates alone without whey protein. After 3 hours of ingesting the supplement blood samples will be collected again

Change of serum C reactive protein and albumin from 12 hours fast (baseline) to 3 hours after ingestion of the oral supplement

Inclusion Criteria: Male young healthy volunteers Exclusion Criteria: or will be excluded. Individuals with obesity (calculated body mass index above 30 kg/m2) Participants reporting consumption of alcoholic beverages Consumption of any nutritional supplement during the study period