(1) Background: The aim of this study was to evaluate the influence of the lockdown due to COVID-19 pandemic, eating and physical activity behaviours, in a University population. A healthy diet such as the Mediterranean Diet (MD) pattern, rich in fruit and vegetables can prevent degenerative diseases such as obesity, diabetes, cardiovascular diseases, etc. (2) Methods: We conducted a cross-sectional study, data were collected by an anonymous online questionnaire. Participants completed a survey consisting of 3 sections: sociodemographic data; dietary and physical activity behaviour; questionnaire of the Mediterranean Diet (MEDAS-14) and the emotional eater questionnaire Garaulet (EEQ). (3) Results: A total of 168 participants completed the questionnaire 66.7% women, from Spain 79.2%, 76.8% students, living in family home 76.2% and in normal weight 66.1% . Our population did the grocery 1 or less per week (76.8%); decreased or stay the same the consumption of fruits (57.1%), vegetables (58.9%), dairy products (74.4%), pulses (73.2%), fish/seafood (76.8%), white meat (83.3%), red and processed meat (91.1%), snacks (78.6%), rice/pasta/potatoes (78.6%), nuts (83.9%), low alcohol drinks (89.3%), spirits (98.8%) and sugary drinks (91.7%) . Increased cooking time (73.2%) and decreased or stay the same their physical activity (63.7%). University Employees increased more weight (1.01±0.02) than students (0.99±0.03) (p<0.05). 79.8% of the participant obtained a Medium/High Adherence to the MD. Emotional and very emotional eaters were higher in women group (p<0.01). (4) Conclusions: In the event of further confinement, strategies should be implemented to promote a balanced and healthy diet together with the practice of physical activity, taking special care of the group of women and University Employees.