Fatty meats - such as organ meats, processed meats and steak - and fried foods, like potato chips contain unhealthy saturated fats. They can also hinder digestion and immune system function when you face a cold, according Trivieri, Goldberg and Anderson. Other fatty foods to avoid include fries, nachos, hot dogs, meat and cheese-topped pizza, breakfast sandwiches and fast food burgers, steaks, chicken and fried fish, ham and cheese omelets, garlic bread and butter red meat with visible fat.