Is a fruitarian diet actually healthy?

Rarely, if ever: For a short time it may be okay but long term it is deficient in protein (unless nuts, grains, and seeds are included) and essential fatty acids (which can be supplemented) will lead to muscle and bone loss as well as other health problems. There may be also be a deficiency of other essential nutrients, especially vitamin B12 and other b vitamins, depending on the types of fruit consumed.