Is it what is in processed food that is bad for us or what is lacking in fast foods that is bad? If it is what is lacking then supplements (maybe based on bloo

Is it what is in processed food that is bad for us or what is lacking in fast foods that is bad? If it is what is lacking then supplements (maybe based on blood tests) could help. If it is what is in the food the only thing that would help is to stop eating them. It's probably both, but identifying what is missing could at least let us repair some of the harm. Beyond vitamins and fiber what else does processed food lack? Specific forms of protein? Variety? Bacteria for your microbiome? Long term energy providing complex carbs to keep you active?