Are Fat Mass and Lean Mass Associated with Grip Strength in Adolescents?

Background: The interaction between lean body mass (LBM) and fat mass index (FMI) with grip strength (GS) has not been explored in the same analysis model in adolescents. This study thus aims to analyze the association between FMI and LBM with GS. Methods: This cross-sectional study was conducted with data from the 2016 follow-up of the 1997/98 Birth Cohort of São Luís. Grip strength was assessed by the Jamar Plus + dynamometer. The LBM and FMI indexes were assessed [ratio of the mass (lean or fat-kg) to height (m2)]. The confounding variables identified for the relationship between FMI and LBM with GS in the same analysis model, by directed acyclic graph (DAG), were sex, age, race, work, alcohol consumption, smoking, physical activity, and consumption of ultra-processed foods and culinary preparations, used in the adjusted analysis. Results: A total of 2339 adolescents (52.5% girls) were analyzed. The boys have a higher GS than the girls. In the adjusted analysis, with each increase of 1 kg/m2 in the FMI, GS was reduced by 0.72 kgf for boys and 0.35 kgf for girls. At each increase of 1 kg/m2 in the LBM, GS increased by 2.18 kgf for boys and 1.26 kgf for girls. Conclusions: FMI was associated with lower GS regardless of the LBM. LBM was associated with higher GS regardless of the FMI.

Intake of ultra-processed foods is associated with inflammatory markers in Brazilian adolescents.

OBJECTIVE: To evaluate the association of the consumption of foods of the ultra-processed group (UPF) with inflammatory markers in the adolescent population in Northeastern Brazil. DESIGN: A cross-sectional population-based study. Food consumption was evaluated using two 24-h dietary recalls using the NOVA classification for food processing levels. The following inflammatory markers were evaluated: adiponectin, IL-6, IL-8, C-reactive protein (CRP) and TNF-α. Multivariate linear regression was used to investigate the association between the percentage of UPF energy contribution and inflammatory markers. SETTING: São Luís, Maranhão, Brazil. PARTICIPANTS: The sample consisted of 391 male and female adolescents, aged from 17 to 18 years. RESULTS: The average daily energy consumption by adolescents was 8032·9 kJ/d, of which 26·1 % originated from UPF. The upper tertile (T3) of UPF consumption presented higher intake of simple carbohydrates, lipids, saturated fat, and Na and lower protein intake. Individuals in T3 presented higher serum leptin and CRP levels (P < 0·05). Adolescents with UPF energy consumption ≥30·0 % (tertile 3 of UPF) had a 79 % (exp (0·58) = 1·79) increase in IL-8 levels when compared with adolescents in tertile 1 of UPF (P = 0·013). CONCLUSIONS: The association between the consumption of UPF, poor quality diet and pro-inflammatory markers have important harmful effects that can be observed as early as in adolescence.