 The fruitarian diet promoted by Ratcliffe is not considered advisable by many, if not all, mainstream nutritionists.Specifically, there are concerns that raw vegan diets heavy in produce with very few sources of nuts and seeds are too low in protein, essential amino acids, fats, vitamin D, vitamin B12, calcium, iodine, iron, and omega 3 fatty acids.These diets are also associated with higher risk of weight gain, diabetes, and tooth decay because of the high sugar content.