Integrated Behavioral Profiles of Physical Activity and Dietary Intake in Young Adults and Their Associations with Lower Limb Injury Occurrence

Background/Objectives: To delineate integrated lifestyle profiles combining physical activity (PA) and dietary intake (DI) and test their links with lower limb injury in physically active young adults. Methods: We analyzed a cross-sectional convenience sample of university students (men: n = 91, 20.5 ± 1.0 years; women: n = 118, 20.3 ± 0.8 years). PA (IPAQ) and DI (QEB) were assessed alongside self-reported injuries. Latent class modeling derived PA–DI profiles. Injury prevalence across profiles was compared (χ²), and logistic regression examined injury odds adjusting for sex, age, and BMI. Results: Four profiles emerged. Two reflected less healthy patterns (Profiles 2–3) and two healthier ones (Profiles 1, 4). Profile 4 showed higher vegetables/legumes/fermented milk and lower fast food/sugary drinks; Profile 3 combined greater sitting and fried/sweetened items with lower walking/milk intake. Overall injury prevalence was 56.9%, ranging from 44.1% (Profile 2) to 66.7% (Profile 4 exceeded Profile 2 in pairwise comparison (χ² (1) = 5.08, p = 0.024)). In adjusted models, men had higher injury odds (OR = 1.94, 95% CI: 1.09–3.48, p = 0.025); profile membership was not independently predictive, and profile × sex interactions were null. Conclusions: Young adults cluster into distinct PA–DI patterns that differ behaviorally, but sex—rather than profile—was the most consistent correlate of injury. Prevention should integrate lifestyle screening with sex-specific strategies.