The moderating role of physical fitness in the relationship between sugar-sweetened beverage consumption and adiposity in schoolchildren

The mediating and moderating associations of cardiorespiratory fitness (CRF) and handgrip strength on the association between dietary patterns and several health outcomes have been previously studied. For instance, handgrip strength has been found as a moderator of the relationship between excess weight and cardiometabolic risk factors in young adults. Similarly, CRF has been shown as a mediator of the association between diet and obesity in children. However, to our knowledge, the role of CRF and handgrip strength on the association between sugar-sweetened beverage (SSB) consumption and adiposity is still unclear. The aim of this study was to determine whether CRF and handgrip strength moderate the association between SSB consumption and adiposity in a population-based sample of Spanish schoolchildren. This cross-sectional study involved 475 schoolchildren (52.0% girls), aged 8–12, from ten schools in Cuenca (Spain). Adiposity was determined as body fat (in kg), which was measured using a bioimpedance analysis system. Data on SSB consumption were gathered by using the Children’s Eating Habits Questionnaire, which was completed by parents. The CRF level was determined by the 20-m Shuttle Run test and Nevill’s curvilinear allometric model. Handgrip strength was determined using a digital dynamometer with adjustable grip. For each unit (in ml/kg/min) of CRF increased, the association between SSB consumption and adiposity was moderated (B = − 0.09, CI 95% − 0.14 to − 0.04). This significant moderation was also found for each 0.01 unit of increased normalized handgrip strength (B = − 0.07; CI 95% − 0.11 to − 0.02). Similarly, the Johnson-Neymann technique established three different regions. The first region shows that the association of SSB consumption on adiposity in participants who had levels of CRF < 43.4 ml/kg/min or handgrip strength < 0.34 was greater and statistically significant. The second region (43.4–57.4 ml/kg/min for CRF; 0.34–0.58 for normalized handgrip strength) depicted that the association between SSB consumption and adiposity was not statistically significant in those with a CRF level or normalized handgrip strength between the lower and upper thresholds. The third region was found at > 57.4 ml/kg/min (for CRF level) and > 0.58 (for normalized handgrip strength), indicating that the association between SSB consumption and adiposity was lower and statistically significant in children above these moderator values. Our results showed that certain levels of CRF and normalized handgrip strength moderate the association between SSB consumption and adiposity in a sample of Spanish schoolchildren. It might be possible that higher physical fitness level in childhood may contribute to reducing the association between SSB consumption and adiposity.