Some people cannot eat meals due to various medical conditions or allergies. For example, those with celiac disease have an immune reaction to gluten, which is found in many foods such as bread, pasta and cereals. People with lactose intolerance cannot digest the sugar in milk and dairy products. People with food allergies may experience a serious reaction when they consume certain types of food. In addition, some people may have difficulty swallowing due to neurological disorders or physical disabilities, making it difficult for them to eat meals. Lastly, some people may choose not to eat due to religious beliefs or personal preferences.