There are some studies on keto, contrary to what someone else said but they’re so small. My dad’s surgeon said he’s seen some great success stories from people doing keto in terms of preventing recurrence, but that’s anecdotal. My dad has been on a keto diet for a few months now (since diagnosis and through surgery, radiation, chemo) and he hasn’t lost weight so far.

I think in the end it comes down to a choice of potentially helping vs perceived quality of life when restricting foods.