Kingdome of Saudi Arabia (KSA) has undergone lifestyle changes that have resulted in unhealthy dietary patterns So this study aims to investigate the frequency, determinants, and the context of Fast Food (FF), and Junk Food (JF) consumption, to study the effect of the Saudi Food and Drug Authority (SFDA) food related policy, and to study the use of Ministry of Health (MOH) calorie guide among Saudi population all over KSA. Through a cross-sectional study recruited 355 randomly selected Saudis stratified to represent the 20 health regions in KSA through a self-administered and validated questionnaire. Ethical approval was obtained for this work. Results; The majority had age distribution between 20- less than 40 y, and 218 (61.4%) were single. The prevalence of FF, and JF consumption was 308 (86.7 %).The most frequently consumed FF in descending order were (French fries, Shawarma, Burger, then Pizza) , while the most frequently consumed JF in descending order were (all kinds of cocoa, and cakes, then Ice cream), and more than half of participants did not drink carbonated soft drinks. Dinner was the main time of consuming FF (79.2%), and soft drinks (55.6%), while sweets were consumed mainly as snack (68.8%). The consumption of FF, and JF were significantly higher among young participants. The most common causes for consuming the above mentioned foods were entertainment 173 (48.5%), eating with friends 100 (28.1%) and due to better taste 92 (25.8%). The majority 48.7% of Saudi were unaware about the SFDA food related policy. Although the use of calorie labeling policy significantly (p less than 0.05) affected the food choices, reduced the average weekly spending on Saudi Riyal, but not on weight loss. We concluded that FF, and JF consumption among Saudis is a prevalent, and complex problem, indicating a critical need for community-based interventions to change the attitudes and behaviors toward healthy eating.