It's typically used in an attempt to convince people to switch to a healthy diet but in my opinion it does a very poor job because:
no-one literally lives to eat, but it's one of the many small pleasures of life that make it enjoyable - false premise
everyone eats to live - a truism
To me, this catchphrase suggest that one should view food as mere sustenance and nothing more and therefore it's bound to embitter rather than persuade, especially when it's aimed at people who have a poor diet.
I believe there is a name for this type of fallacy.