Objective: The objective of this study was to examine changes in freshman students' objectively measured body mass index (BMI), physical activity (PA), and dietary behaviors (consumption of trans fats, sugars, and added sugars) during their first college semester. Methods: Twenty-eight participants (18.32 ± 2.2) completed the dietary (ASA24-US) and PA (wrist-worn ActiGraph accelerometer) assessments. Non-parametric Paired-Wilcoxon signed-rank tests were used to identify the changes in BMI, moderate-to-vigorous intensity PA (MVPA), vigorous-intensity PA (VPA), and nutrition. Results: The analyses showed a statistically significant increase in BMI (M[subscript baseline] = 22.85[2.87] kg/m[superscript 2]; M[subscript post] = 23.53[3.21] kg/m[superscript 2]; p = 0.002, r = 0.53) and MVPA (M[subscript baseline] = 200.94[81.08]; M[subscript post] = 216.92[78.33]; p = 0.031, r = 0.41), but there were no statistically significant changes in VPA or dietary behaviors. Conclusions: Although freshman students' PA and dietary behaviors were relatively healthy, efforts to increase VPA and reduce consumption of added sugars are well warranted.