"what is good for you" is a completely tautological way of defining "a good diet". How can you say you are not just reinforcing your own presuppositions? The o

"what is good for you" is a completely tautological way of defining "a good diet". How can you say you are not just reinforcing your own presuppositions? The only intuitive difference I see in those scenarios is that one has less calories and less fat (which are obviously both essential components of any diet).