They ate meat and fish, just maybe slightly different ones. They ate fruits and vegetables, but again, just slightly different ones.
The point isn’t to eat a particular meat or fruit or vegetable, it’s to avoid foods that were not available until more recently in history after the advent of farming.
What type of meat then. The sources of our meats were not domesticated until the Neolithic Revolution. Fruits and vegetables like the tomato were based on domestication and have very little in common with their wild ancestors..