A survey on hydration and body composition among Italian young athletes.

BACKGROUND: Evidence shows that children water intake are below recommendations and are likely to be insufficient for maintain euhydration. Moreover, childhood obesity is becoming an epidemic. Interestingly, among other factors, the level of hydration may play a role in promoting weight regulation processes. AIMS: Assessing hydration status(HS); detecting daily water intake(DWI), hydration after exercise(HAE), body composition(BC);investigating possible correlations between these variables and practiced sport(PS). METHODS: 351 young athletes(YA)(7-17 years old) were recruited. A questionnaire was used to asses DWI, HAE and PS; to study BC we used BMI percentiles(BMIp), waist to height ratio(WHtR), bioimpedence analysis(BIA);HS was assessed using urine specific gravity(USG). Statistical analysis(Pearson’s chi square, ANOVA, MANOVA, Spearman’s rho test) was performed to test any possible relationships between the variables studied. RESULTS & DISCUSSION: we found similar prevalence of obesity and overweight(OW)(27.9%) to those observed in Italy from other studies, but the prevalence was significantly <(7.7%) when we used WHtR as a marker of central obesity. We found a stronger correlation between BMIp and body cellular mass than BMIp and fat mass(FM), so the use of BMIp on YA may overestimate OW. The > of YA(55.6%) were dehydrated(DH), probably because they had poor DWI(1400±580mL). Comparing DWI with recommendation for Adequate Intake of water(Italy RDAs-2012), we found that YA achieved them but they were not sufficient to achieve euhydration. Comparing DWI with the amount of water needed, estimated using basal metabolic rate(BMR)(ml/kcal energy expenditure), we found that YA did not achieve that amount. The majority of YA(87.7%) stated to drink after exercise, but the amount of water was very lower(500±200mL) than their real needs. DWI was related to the degree of OW, the more the OW the > the DWI. DWI was also related to the PS, YA practicing sports that emphasize leanness had < DWI regardless of BC. Finally, obese YA had > FM if DH. Underweight YA had < FM if DH. Based on our findings we can assume that HS plays a key role in BC and there is a need to make more efforts to teach the importance of hydration in YA.