Isotopic testing shows that early humans primarily subsisted on herbivores and small game, including fish. Please refer to this study for Europe.

Early modern humans also appear to have regularly hunted large herbivores (55–57), but there is also evidence for the use of small game, including fish at some of these sites (15, 16).

Or this study, also from Nature, again studying the first modern humans and late Neandertals in Europe:

based on stable isotopes, the mammoth seems to contribute the major part of the dietary protein of humans in a time range between 50,000 and 30,000 years ago and across wide areas spanning from SW France11 to the Crimean Peninsula53 (Fig. 6, Supplementary Fig. 5–8).

It is inaccurate to state that humans did not eat much meat prior to modern times.