Natural food is an excellent source for providing the nutrition a body needs. It is also low in fat and provides very necessary fiber which helps prevent constipation and reduces cholesterol which leads to arteria sclerosis, cancer and diabetes, which are major causes of death in Thailand. This study is both quantitative and qualitative with the objectives of finding the differences in natural food consumption and the factors affecting dietary habits among the rural migrants who have lived in the city for a period of 1 to 7 years. The study groups are composed of 1.) 285 working males and females, aged 15 to 35, residing in Bangkok and its peripheries and, 2.) residents of the rural community in Nakhorn Phanom. Results of the study showed that there is a reduction in consumption of natural food when people move from the countryside into the city. Second, there are less natural foods available for collection in the city than food produced by farms. The study shows no difference in diet selection base on demographic, economic, social and cultural factors. It was also found in opinions toward organic food factors and availability of the natural food factors had little relation over persons’ decision making. Finally, the study showed that people migrating from the countryside to the city perceive that by eating less natural food their chances of having bad health such as digestive complications may increase. The urban qualitative study showed that people who purchased natural food for consumption did this because they were used to the taste. Still, they felt that natural food found in the city was unsanitary. Furthermore, there has been a reduction in the amount and variety of natural food resources in the countryside because of destruction and environmental changes. This has also led to an increase in the rural consumption of purchased food which can cause improper diets.