I believe so, though not as the only thing in their diet. They need crunchy foods like clams and snails to wear down their teeth. You can feed foods like bloodworms, mysis shrimp, and brine shrimp in between for a snack. However, their main diet should be things like clams, snails, shrimp with shell on (uncooked or live is best), mussels, etc. Also, do not feed krill as the main diet since it can cause lockjaw. It is fine for a treat though.
Here's a link to a page with several articles on feeding. That site in general has the most accurate and plentiful information on all sorts of puffers as well as more general info like feeding and teeth trimming. The third artcile in the link is about what to feed and why. Frozen and live foods are the best since they are the most readily taken by puffers as well as being the most nutritious. Also, live foods provide a hunt, which is essential for the well-being of the puffer who needs something to stimulate his intelligence and hunting instinct. They are much happier with a chance to hunt.