Relation of dietary glycemic index, glycemic load, and fiber and whole-grain intakes during puberty to the concurrent development of percent body fat and body mass index.

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.