Unhealthy foods include fats (especially of animal origin), “fast” foods (which are low in fibre and vitamins), foods high in salt and tropical oils (e.g., fried potato crisps/chips), and cream-based (“white”) sauces (which are high in fat).ny food that is not regarded as being conducive to maintaining health; UFs include fats, in particular of animal origin, 'fast' foods–low in fiber and vitamins; 'junk food'–eg, potato and corn chips, pretzels, crackers–high in salt and tropical oils; 'white sauces'–northern Italian cuisine, high in fat. See Junk food.