A nutritionist is a person who advises on matters of food and nutrition impacts on health. Different professional terms are used in different countries, employment settings and contexts — some examples include: nutrition scientist, public health nutritionist, dietitian-nutritionist, clinical nutritionist, and sports nutritionist.
Some use the terms "dietitian" and "nutritionist" as basically interchangeable. However in many countries and jurisdictions, the title "nutritionist" is not subject to professional regulation; any person may call themselves a nutrition expert even if they are wholly self-taught. In most US states, parts of Canada, Australia, and the United Kingdom, the term nutritionist is not legally protected, whereas the title of dietitian can be used only by those who have met specified professional requirements. One career counselor attempting to describe the difference between the two professions to Canadian students suggested "all dietitians are nutritionists, but not all nutritionists are dietitians."
Regulation of the title "nutritionist" 
For example, the Nova Scotia Dietetic Association is the regulatory body for professional dietitians and nutritionists in that province, authorized by legislation, the Professional Dietitians Act, "to engage in registration, quality assurance, and when necessary, the discipline of dietitians in Nova Scotia to ensure safe, ethical and competent dietetic practice." Professional requirements include a Bachelor's Degree in Dietetics/Nutrition from an accredited university, a program of practical training, and successful completion of a registration examination (the "Canadian Dietetic Registration Examination" or CDRE).
In Morocco, "Nutritionist" is a protected title and might refer to a researcher in the field of nutrition or to a person who practices therapeutic nutrition. To hold the title of Nutritionist, a person should have carried doctoral studies in the field of nutrition and obtained a Ph.D.
On the other hand, the title of "Dietitian" is given to whoever carries studies in nutrition schools for 3 years and obtains an B.Sc. However, unlike nutritionists, dietitians are not given authorizations to open private offices and to practice.
South Africa 
In South Africa, nutritionists must be registered with the Health Professions Council of South Africa. The Council regulates the professional titles of "Nutritionist", "Student Nutritionist", and "Supplementary Nutritionist", along with "Dietitian, "Student Dietitian", and Supplementary Dietitian". Requirements for eligibility for registration include a recognized Bachelors degree from an accredited educational institution. The undergraduate training should include the three practice areas of therapeutic nutrition, community nutrition, and food service management.
United Kingdom 
"Nutritionist" is not a protected term in the UK, unlike "dietitian"; the latter must be registered with the Health Professions Council. Different organizations use their own criteria to define a nutritionist. According to one of these, the Nutrition Society, “the function of a nutritionist is to elicit, integrate, disseminate and apply scientific knowledge drawn from the relevant sciences, to promote an understanding of the effects of nutrition, and to enhance the impact of food on health and well-being of animals and/or people”. The Society accredits nutritionists, conferring the titles Associate Nutritionist (ANutr) and Associate Public Health Nutritionist (APHNutr). For these it considers an undergraduate training  sufficient for associate membership. Full registration as a Registered Nutritionist (R Nutr.), or Registered Public Health Nutritionist (RPHNutr), requires at least three years work experience and the fulfilment of key competencies required to operate safely and effectively. Members must also agree to abide by a code of ethics and maintain the Society's standards for working with the public.
Although there are many undergraduate and postgraduate degrees in nutrition in the UK, anyone can refer to him- or herself as a nutritionist without any qualifications. A person can legally describe themselves as a nutritionist and obtain qualifications such as a degree by mail from a non-accredited institution. The Association For Nutrition is the new professional body for the regulation and registration of nutritionists (including public health nutritionists, exercise nutritionists, and animal nutritionists). The AFN aims to protect the public, and promote wellbeing, by admitting to the UK Voluntary Register of Nutritionists only those who demonstrate high ethical and quality standards, founded on evidence-based science. The Association sets proficiency and competency criteria, promotes continuing professional development and safe conduct, and accredits university undergraduate and postgraduate courses.
Since 2002, the number of jobs for nutritionists has reportedly grown faster in the National Health Service (NHS) than in any other sector. Despite it being recognized that nutritionists have an increasingly important role to play in health care in the UK, the NHS employs fewer dietitians each year and the profession itself is shrinking, with nutritionists being seen as 'non-essential' support staff.
Dietitians and nutritionists in India held about 150,000 jobs in 2011. More than half of all Dietitians and nutritionists worked in hospitals, nursing homes, and physician's offices and clinics.
The need for Dietitians and nutritionists is increasing every day with sedentary lifestyles, high consumption of fast food and other food related health disorders at an all-time high. They also help to reduce the resistance for diseases, such as malaria, by providing diets rich in protein and calories. Dietitians and nutritionists can find employment in hospitals, fitness centres, spas, health clubs, colleges, nursing care facilities, canteens, hotels, government, etc. One can also work as consultants or do private practice. The starting salary in this field is around Rs. 20,000 to Rs. 25,000 per month.
Several professional associations are available to serve Nutritionists, Dietitians, and Food technologists in India e.g. Nutrition Society of India, Food Scientists and Nutritionists Association India, Indian Dietetic Association etc.
See also 
- United States Bureau of Labor Statistics: Occupational Outlook Handbook, 2010-11 Edition - Dietitians and Nutritionists. Accessed 11 March 2011.
- Nutrition Encyclopedia, edited by Delores C.S. James, The Gale Group, Inc.
- Athabaska University: How to become a Dietitian (or Nutritionist), by Julia McDonald, Athabaska University Counselor. Accessed 11 March 2011.
- Canadian Information Centre for International Credentials: Information for foreign-trained dietitians and nutritionists Accessed 24 January 2012.
- Nova Scotia Dietetic Association.
- Health Professions Council of South Africa: Dietetics and Nutrition Professional Board. Accessed 1 April 2011.
- UK Health Professions Council: Protected titles. Accessed 14 March 2011.
- Nutrition Society
- Specialist Competencies in Nutrition Science . Accessed 11 March 2011.
- "Undergraduate courses accredited by the Nutrition Society". Nutrition Society. Retrieved 2007-07-19.
- Nutrition Society: Nutrition Profession. Accessed 11 March 2011.
- National Health Service Careers: Nutritionist. Accessed 11 March 2011.
- USA (2012-03-13). "Broadening career opportunities in dietetics... [J Am Diet Assoc. 1999] - PubMed - NCBI". Ncbi.nlm.nih.gov. Retrieved 2012-03-29.
- Messer, Ellen (January 1989). "Indian nutritionists and international nutritional standards: Concepts and controversies". Social Science and Medicine 29 (12): 1393–1399.