European Journal of Nutrition · Aug 3, 2026

Circadian distribution of carbohydrate intake during adolescence and association with risk markers of type 2 diabetes in adulthood-the role of chronotype

By Jankovic N, Schmitting S, Perrar I et al.

BACKGROUND: Adolescence is a critical phase characterized by temporary insulin resistance and a tendency for a later chronotype, potentially influencing the risk of developing type 2 diabetes (T2D) later in life. This study explores how morning and evening carbohydrate (CHO) intake during adolescence are prospectively related to T2D risk factors-such as insulin resistance (HOMA2-IR), liver fat indices, and subclinical inflammation- in adulthood while considering the role of chronotype. METHODS: This analysis utilizes data from 224 DONALD study participants (58% female) who provided 3-day weighed dietary records during adolescence (median age = 12 years) and a blood sample in adulthood (median age = 22 years). Owing to detected interactions between the timing of CHO intake i.e. CHOevening(E%)-CHOmorning(E%), (eveningness in CHO intake) and chronotype, analyses were stratified accordingly. RESULTS: An inverse relationship was found between morning CHO intake (before 11 a.m.) and adult HOMA2-IR levels (beta and 95% CI for high (T3) vs. low (T1): -0.12 (-0.21; -0.04), ptrend = 0.01). For individuals with an earlier chronotype, a higher "eveningness in CHO intake" was linked to higher HOMA2-IR (ptrend = 0.03). Conversely, those with a later chronotype exhibited the lowest HOMA2-IR in the median "eveningness in CHO intake" category (T2). No significant associations were observed between evening CHO intake and other risk markers. CONCLUSION: Consuming CHOs in the morning during adolescence is associated with lower HOMA2-IR in adulthood, irrespective of chronotype. However, the favorable morning CHO intake amount appears to vary by chronotype, indicating a personalized approach may be beneficial.

doi.org/10.1007/s00394-026-04056-xOpen accessPubMed 42545501Populations