I spent my career working in fields regulated by the FDA. The agency is science-based and, in general, does a very, very good job.
The real health threat from food is microbial contamination, due mainly to temperature abuse (not keeping things cold or not cooking them enough) and poor worker sanitation (wash those hands!). An estimated 40-50 million illnesses and 3,000 deaths per year.
Of course, if people do not eat balanced diets they jeopardize their health. I don't see why you'd blame the FDA for that.