Obesity among young adults is a growing problem in the United States and is related to unhealthy lifestyle habits, such as high caloric intake and inadequate exercise. Accurate assessment of lifestyle habits across obesity stages is important for informing age-specific intervention strategies to prevent and reduce obesity progression. Using a modified version of the Edmonton Obesity Staging System (mEOSS), a new scale for defining obesity risk and predicting obesity morbidity and mortality, this cross-sectional study assessed the prevalence of overweight/obese conditions in 105 young adults and compared their lifestyle habits across the mEOSS stages. Descriptive statistics, chi-square tests, and one-way analyses of variance were performed. Eighty percent of participants (n = 83) fell into the mEOSS-2 group and had obesity-related chronic disorders, such as diabetes, hypertension, and/or dyslipidemia. There were significant differences in dietary quality and patterns across the mEOSS stages. Findings highlighted the significance of prevention and early treatment for overweight and obese young adults to prevent and cease obesity progression.