Existing literature is conflicting about the association between body mass index (BMI), body image, quality of life, and disordered eating in samples of community youth, and youth in pediatric weight management programs. This thesis explored these associations through two studies. Study 1 was a meta-analysis examining the association between BMI and health outcomes and Study 2 was a quantitative study of the bidirectional associations between these variables in a sample of youth in a weight management program. Meta-analytic results indicated that BMI was significantly associated with body image (r = -0.41; N = 57; p<.001), disordered eating (r = 0.14; N = 46; p<.001), and quality of life (r = -0.22; N = 21; p<.001). However, there were significant gender and construct differences, such that for most body image subgroups the association between BMI and body image was significantly larger for female samples. Additionally, studies that used figure rating scales compared to Likert assessments of body image had stronger associations with BMI and no gender differences. In Study 2, 209 youth (111 female; ages 4-18) were included in a retrospective chart review from a pediatric weight management program. Latent growth modelling was used to examine univariate growth trajectories of each variable and the bidirectional associations between body esteem, disordered eating, quality of life, and BMI over time. It was hypothesized that: 1) higher initial body esteem would be associated with lower disordered eating and higher quality of life at baseline, 2) higher initial body esteem would be associated with more favourable changes in disordered eating and quality of life over time, and 3) increases in body esteem would be associated with decreases in disordered eating and increases in quality of life over time. Results indicated that baseline body esteem was associated with baseline emotional eating and quality of life, however body esteem was relatively stable over time and was not associated with changes in quality of life, or disordered eating over time. These results have implications for our understanding of the stability of body esteem over time, body image measurement and terminology, and its role in pediatric weight management programs.