Short-term changes in added sugar consumption by adolescents reflected in the carbon isotope ratio of fingerstick blood:

Background:Consumption of added sugars (AS) and sugar-sweetened beverages (SSB) may adversely affect adolescents’ weight and cardiovascular disease risk. Reliance on self-reported dietary assessment methods is a common research limitation, which could be overcome by dietary intake biomarkers.Aim:The investigation was a proof-of-concept study to evaluate the proposed carbon isotope ratio (δ13C) biomarker of AS intake in adolescents, using a controlled feeding design.Methods:Participants (n = 33, age 15.3 years, 53% female) underwent two seven-day controlled feeding periods in a randomly assigned order. Diets were matched in composition except for AS content (5% or 25% of total energy). Fasting fingerstick blood samples were collected daily during each diet period.Results:Fingerstick δ13C values changed from day 1 to 8 by –0.05 ± 0.071‰ on 5% AS, and +0.03 ± 0.083‰ on 25% AS (p ≤ 0.001). Reliability was demonstrated between day 7 and 8 δ13C values on the 5% (ICC = 0.996, p ≤ 0.001) and 25% (ICC = 0.997, p ≤...