The usual way of starting a career in nutrition is to study for a degree in nutrition and/or dietetics (or a closely related bioscience) at a university. Most careers will require at least an undergraduate degree (BSc), and some may require postgraduate study too. An undergraduate degree usually takes 3 or 4 years to complete. Science subjects such as chemistry and/or biology are generally required at A2 level or their equivalent in the Scottish Higher or Irish Leaving Certificates. If you did not study science at school, you may be able to enter university after successfully completing a science access/foundation course. Information about entry requirements is available via university prospectuses and Course Leaders or Admissions Tutors. Also, the UCAS (Universities and Colleges Admissions Service) provides information on the many varied courses that now exist (www.ucas.com). Your careers advisor should also be able to provide advice and information.
A list of available courses that are accredited by the Association for Nutrition (AfN) can be found here. Graduating from one of these courses will allow you direct entry onto the UK Voluntary Register of Nutritionists (UKVRN).
A list of available courses in dietetics that will lead to qualification as a dietitian can be found here.