Humankind has faced various pandemics in history. The food supply chain is one of the foremost vital sectors of the economy, and COVID-19 has had a clear bearing on it from the field to the consumer. In the light of recent challenges in the food supply chain, there is currently considerable concern regarding food production, processing, distribution, and demand. COVID-19 resulted in the movement restrictions of staff, changes in the demands of consumers, closure of food production facilities, restrictive food trade policies, and monetary pressures in the food supply chain. This study describes the impact of the COVID-19 health crisis on people’s interests, opinions, and behaviour towards food. Additionally, an online questionnaire (Spanish population, n = 232) studied the changes in food shopping habits during the pandemic. To try to cover the whole Léon territory and reach the greatest number of persons through mobile phones, tablets, and computers, the questionnaire was created using the Google Forms tool and distributed using instant messaging apps such as WhatsApp, social media such as Facebook and Twitter, social networking sites such as LinkedIn and ResearchGate, and email through snowball sampling. The statistical analysis was carried out under the SPSS programme. The results are presented in the form of means and distributions. The differences between subgroups have been evaluated using student’s t-test. The level of statistical significance used in all cases was p < 0.05. This study is focused on evaluating changes in food consumption habits of the Spanish adult population throughout the COVID-19 lockdown. The study is supported by a web-based survey targeting the adult general population. From this study, we are able to conclude that the studied Spanish adult population is extremely close to from having good healthy dietary habits, considering the Mediterranean Diet as a reference of healthy uptake. An improvement of dietary behaviours throughout the COVID-19 confinement has been discovered. Health-related food selections involved increased intake of fruits, vegetables, and legumes and decreased intake of red meat, alcohol, fried foods, or pastries compared to their pre-pandemic habits.