The authors prospectively examined whether change in dietary glycemic index (GI), glycemic load (GL), fiber intake, or whole-grain intake during puberty is associated with concurrent change in percentage of body fat (%BF) or body mass index (BMI; weight (kg)/height)(2). Linear mixed-effects regression analyses were performed in 215 participants from the Dortmund Nutritional and Anthropometric Longitudinally Designed (DONALD) Study (Dortmund, Germany) who possessed weighed 3-day dietary records and anthropometric data at puberty onset (defined by age at takeoff) and over the subsequent 4 years (1988-2007). Neither changes in dietary GI, GL, fiber intake, nor whole-grain intake were associated with concurrent changes in %BF throughout puberty (change in %BF: -0.03 (standard error (SE), 0.11) per standard deviation (SD) increase in GI (P = 0.8); -0.01 (SE, 0.11) per SD increase in GL (P = 0.9); 0.02 (SE, 0.14) per SD increase in fiber intake (P = 0.9); and 0.09 (SE, 0.13) per SD increase in whole-grain intake (P = 0.5)). Similarly, no concurrent associations were observed between these dietary factors and BMI SD scores. Associations of dietary GI with %BF and BMI SD score differed between overweight and normal-weight adolescents (for concurrent association, P for interaction was 0.03 for %BF and 0.08 for BMI SD score). Dietary GI, GL, and fiber and whole-grain intakes in healthy, free-living adolescents do not appear to be relevant to the development of %BF or BMI during puberty.