Dieticians base their advice on the Reference Nutrient Intake (RNI) of nutrients. RNI guidelines are based on the amount of a nutrient required to avoid diseases of deficiency. They do not take into account biochemical individuality i.e. the fact that each person is unique and therefore has unique needs.

In contrast, a nutritional therapist typically works in private practice and consults with individuals on a one to one basis, sometimes receiving NHS referrals. A nutritional therapist may work with healthy individuals in order to prevent disease, and those that are ill to ease and minimise symptoms of a developed disease.

A nutritional therapist takes into account the unique dietary needs of each individual and aims to promote optimal health with personalised diet and lifestyle changes and therapeutic supplementation.

This article from the Alliance for Natural Health illustrates the difference in approach of dieticians and nutritional therapists — http://anhinternational.org/2012/01/26/anh-feature-dieticians-and-nutritional-therapists-never-the-twain-shall-meet/