What fruits?
They may have had berries occasionally, and when dom these appear? Late summer, autumn - before winter, that means. These wild berries were more soar than sweet, but contained a little sugar nevertheless. That sugar triggered an insuline reaction that transported the sugar into the fat depposits, forn the winter. So - it made sense, helping them to survive by storing a little extra of energy in their fat tissue.
The berries back then were not like the berries we know today. Most fruits of today were not existent either. And the same goes for the vegetables of the modern present.
And already back then - most plants were toxic for humans, including the overwhelming majority of berries! Which still is the case today. The big lion's share of berries globally known in botany, are toxic for us. And by toxic I mean:
lethal. Fruits are very specialised for very certain species only with which the plant exists in a kind of symbiosis, so that the animal spreads the seeds. Fruits are not meant to be eaten by just anyybody, but only by a small handful of very specific animal species for which the plant has designed these fruits and to which the animal's metabolism is adapted. Cooperation between total specialists.
Us poor humans are practically always excluded!
