We face a problem trying to say what the villagers of Skara Brae ate. Vegetable matter does not preserve as well as animal. So, while there is plenty of evidence to tell us about its meat content, little remains to help us detail what part fruits and cereals played in the diet.
However, we do know that they cultivated barley and a little wheat. They may have baked bread. In all likelihood they collected wild plants, herbs, fruits and nuts. They may have brewed alcoholic beers by fermenting local plants.