Increasing evidence suggests that social and physical environments are important determinants of obesity and physical activity (PA) in youth ,. However, only limited research has investigated social and environmental determinants across the full continuum of sedentary and PA intensities (i.e., sedentary (SB), light (LPA), moderate, and vigorous (MVPA)) . This may be particularly important in underserved (low-income, racial/ethnic minority) and overweight/obese youth who display a greater number of cardiometabolic risk factors  and face increased barriers for engaging in PA .
The current study utilizes the bioecological model  to provide a guiding framework for understanding individual, family, and environmental determinants of SB, LPA, and MVPA in youth. Additionally, the EnRG framework adds to the bioecological model by hypothesizing that dual-processes are important in testing whether environmental factors may influence behavior both directly and indirectly . Previous studies have supported perceived and objective environmental factors as moderators of the link between individual cognitive factors and behavior ,. Consistent with the bioecological model and the EnRG framework’s emphasis on cognitive factors such as perceived behavioral control, one potentially important individual level factor is self-efficacy. Previous reviews , meta-analyses , and studies with underserved youth  have also shown that self-efficacy is a key cognitive factor in understanding youth’s MVPA. At the environmental level, key factors in understanding youth MVPA have included home and neighborhood characteristics such availability of resources, safety, and neighborhood social support ,. However, this study expands on previous research by hypothesizing that parenting variables including parent support , monitoring and limit-setting -, and parental nurturance  will be important determinants of SB and PA in youth beyond environmental factors.
The influence of social environmental and parenting factors may also differ as a function of PA intensity . Although few investigators have evaluated a broader continuum of sedentary and PA intensity outcomes, evidence is building supporting health benefits of engaging in LPA and limiting SB -. LPA has been defined as energy expenditure at the level of 1.6-2.9 metabolic equivalents (e.g., slow walking, sitting and writing, cooking, washing dishes), increases metabolic rate, and contributes to total daily energy expenditure . Targeting increasing LPA as a way to decrease SB may be a unique intervention strategy in high-risk youth (minority, overweight/obese) and offers a number of potential benefits compared to targeting MVPA. LPA may be easier to increase given its higher occurrence and ability to address common barriers of MVPA such as injury, safety, cost and access concerns and feeling embarrassed of low skill levels or sweating -. Overweight/obese youth may also benefit more from targeting increases in LPA compared to healthy-weight individuals due to the relative increased energy expenditure from lighter activities .
Despite the health benefits and potential intervention opportunities of LPA, many studies, including national surveillance studies, do not measure LPA or sedentary behavior (SB) ,. While studies have shown that health behaviors cluster in consistent and inconsistent ways , previous literature has tended to emphasize only one behavior within the SB and PA spectrums ,. Thus, although a substantial amount of literature has investigated self-efficacy, parenting factors, and home and neighborhoods supports in MVPA, findings remain mixed ,, and literature examining these key factors in relation to SB or LPA is lacking. Therefore, the current study expands on previous studies by investigating self-efficacy, parenting, and perceptions of social environmental factors across all activity intensities, including SB, LPA, and MVPA.
Considering multiple systems simultaneously (e.g., self-efficacy, parenting, and social environmental factors) can facilitate a broader, contextual, and more complete understanding of the multiple determinants of SB, LPA, and MVPA. However, a recent review showed studies on family and environmental correlates of SB and MVPA, specifically in underserved youth, are inconsistent and seldom investigate influences from multiple levels . Thus, the purpose of the current study was to examine associations of individual (i.e., self-efficacy), social (i.e., parental support, nurturance, limit-setting, and monitoring), and environmental (perceptions of home resources and neighborhood supports for PA) factors with SB, LPA and MVPA in overweight/obese, underserved adolescents.