To comparatively analyze nutrient intake and dietary adequacy on weekdays (WKDs) and weekends (WKNs) among undergraduate students. Participants: University students (N = 210), 18-30 years old. Methods: A two-day food record was used. Intake of energy, macronutrients, micronutrients and fiber were calculated, without and with an adjustment for 2000 kcal of energy and compared to the corresponding nutritional requirements. Results: Energy and macronutrients' intake was higher on WKNs (1,776.84 ± 40.68 vs. 2,025.76 ± 52.46 kcal; p < 0.05). There was a high predominance of hypocaloric diet on both WKDs (72%) and WKNs (57%). A low prevalence (<50%) of favorable intake level of most micronutrients and fiber was found on WKDs, WKNs, or both. There was a lower favorable intake of vitamins A, C, iron, and magnesium on WKNs, after adjusting for 2000 kcal. Conclusion: Undergraduate students showed an unfavorable nutrient intake and poor dietary quality on WKNs. Interventions that promote healthy eating are needed.