Dietitians supervise the preparation and service of food, develop modified diets, participate in research, and educate individuals and groups on good nutritional habits. The goals of dietitians are to provide medical nutritional intervention, and to obtain, safely prepare, serve and advise on flavorsome, attractive, and nutritious food for patients, groups and communities. Dietary modification to address medical issues involving dietary intake is a major part of dietetics (the study of nutrition as it relates to health). For example, working in consultation with physicians and other health care providers, a dietitian may provide specific artificial nutritional needs to patients unable to consume food normally. Professional dietitians may also provide specialist services such as in diabetes, obesity, oncology, osteoporosis, pediatrics, renal disease, and micronutrient research.
Different professional terms are used in different countries and employment settings,
for example, clinical dietitian, community dietitian, dietetic educator, foodservice dietitian, registered dietitian, public health dietitian, therapeutic dietitian, or research dietitian.
In many countries, only people who have specified educational credentials and other professional requirements can call themselves “dietitians” — the title is legally protected. The term “nutritionist” is also widely used; however, the terms “dietitian”
and “nutritionist” should not be considered interchangeable — the training, regulation and scope of practice of the two professional titles can be very different across individuals and jurisdictions.
In many countries, the majority of dietitians are clinical or therapeutic dietitians, such as the case of the United States, the United Kingdom, and much of Africa. In other countries they are mostly foodservice dietitians, such as in Japan and many European countries.
Dietitians in practice
Clinical dietitiansClinical dietitians work in hospitals, nursing care facilities and other health care facilities to provide nutrition therapy to patients with a variety of health conditions, and provide dietary consultations to patients and their families. They confer with other health care professionals to review patients’ medical charts and develop individual plans to meet nutritional requirements. Some clinical dietitians will also create or deliver outpatient or public education programs in health and nutrition.  Clinical dietitians may provide specialized services in areas of nourishment and diets, tube feedings (called enteral nutrition), and intravenous feedings (called parenteral nutrition) such as total parenteral nutrition (TPN) or peripheral parenteral nutrition (PPN). They work as a team with the physicians, physician assistants, physical therapists, occupational therapists, pharmacists, speech therapists, social workers, nurses, dietetic technicians, and other careers to provide care to patients. Some clinical dietitians have dual responsibilities with patient nutrition therapy and in foodservice or research (described below).
Community dietitians work with wellness programs, public health agencies, home care agencies, and health maintenance organizations. These dietitians apply and distribute knowledge about food and nutrition to individuals and groups of specific categories, life-styles and geographic areas in order to promote health. They often focus on the needs of the elderly, children, or other individuals with special needs or limited access to healthy food. Some community dietitians conduct home visits for patients who are too physically ill to attend consultations in health facilities in order to provide care and instruction on grocery shopping and food preparation.
Foodservice dietitians or managers are responsible for large-scale food planning and service. They coordinate, assess and plan foodservice processes in health care facilities, school food service programs, prisons, restaurants, and company cafeterias. These dietitians may perform audits of their departments to ensure quality control and food safety standards, and launch new menus and various programs within their institution to meet health and nutritional requirements. They train and supervise other food service workers such as kitchen staff, delivery staff, and dietary assistants or aides.
Gerontological dietitians are specialist in nutrition and aging. They work in nursing homes, community-based aged care agencies, government agencies in aging policy, and in higher education in the field of gerontology (the study of aging).
Pediatric dietitians provide nutrition and health advice for infants, children, and adolescents. They focus on early nutritional needs, and often work closely with doctors, school health services, clinics, hospitals and government agencies, in developing and implementing treatment plans for children with eating disorders, food allergies, or any condition where a child’s diet factors into the equation, such as childhood obesity.
Research dietitians are involved with dietetics-related research conducted in hospitals, universities, government agencies, food and beverage companies, and the pharmaceutical industry. They may conduct research in clinical aspects of nutrition, for example, the effects of diet on cancer treatment. They may focus on social sciences or health services research, for example, investigate the impact of health policies or behaviour change, or evaluate program effectiveness. They may survey foodservice systems management in order to guide quality improvement. Some research dietitians study the biochemical aspects of nutrient interaction within the body. In universities, they also may have teaching responsibilities. Some clinical dietitians’ roles involve research in addition to their patients care workload.
Administrative or management dietitians oversee and direct all aspects of food policy and large-scale meal service operations in hospitals, government agencies, company cafeterias, prisons, and schools. They recruit, train and supervise employees of dietetics departments including dietitians and other personnel. They set department goals, policies and procedures; purchase food, equipment and supplies; maintain safety and sanitation standards in food preparation and storage; and keep records to monitor areas such as budget control and client information.
Business dietitians serve as resource people in food and nutrition through business, marketing and communications. Dietitians’ expertise in nutrition is often solicited in the media — for example providing expert guest opinion on television and radio news or cooking shows, columnist for a newspaper or magazine, or resource for restaurants on recipe development and critique. Business dietitians may author books or corporate newsletters on nutrition and wellness. They also work as sales representatives for
food manufacturing companies that provide nutritional supplements and tube
Consultant dietitian is a term sometimes used to describe dietitians who work under contract with health care facilities or in private practice, such as used in Canada and
the United States. The term ‘consultant’ in this case should not be confused with the identical title reserved for certain medical doctors in countries such as the United Kingdom andIreland. Consultant dietitians contract independently to provide nutrition services and educational programs to individuals and health care facilities as well
as sports teams, fitness clubs, supermarkets, and other health and nutrition
Other nutrition personnel
These titles are general designations of nutrition personnel; specific titles may vary across countries, jurisdictions and employment settings.
Dietetic technicians are involved in planning, implementing and monitoring nutritional programs and services in facilities such as hospitals, nursing homes and schools.
They assist in education and assessment of clients’ dietary needs, and may specialize
in nutritional care or foodservice management. Dietetic technicians usually work with, and under the supervision of, a registered dietitian.
The training requirements and professional regulation of dietetic technicians vary across countries, but usually include some formal (postsecondary) training in dietetics and nutrition care. In jurisdictions where the profession is regulated, such as in the United States, the title “Dietetic Technician, Registered” (DTR) may be used.
In the United States, the American Dietetic Association (ADA) confers the “Dietetic Technician, Registered” (DTR) credentials. Qualified DTRs possess a specialized Associate Degree from community college programs which are accredited by the ADA’s Commission on Accreditation of Dietetics Education (CADE). They must complete a dietetic internship with a minimum of 450 supervised practice hours in the areas of Food Service Theory and Management, Community Dietetics, and Clinical Dietetics. They must also successfully pass a national registration examination administered by the Commission on Dietetic Registration (CDR) of the ADA. The DTR is an ADA-credentialed nutrition practitioner who works independently in many nutrition settings; however, when performing clinical dietetics, they must work under the supervision of a Registered Dietitian. Some states have legislation specifying the scope of practice for the DTR in medical nutrition therapy settings.
Effective June 1, 2009, a new pathway to becoming a Registered Dietetic Technician has been made available by the Commission on Dietetic Registration. Students may take the DTR examination without attending an internship after completion of a Baccalaureate degree granted by a US regionally accredited college/university, or foreign equivalent, and completion of a CADE Didactic Program in Dietetics or Coordinated Program in Dietetics. Applicants must take and pass the CDR Dietetic Technician Registration Exam to qualify for the DTR credential. 
Dietary assistants, also known as “nutrition assistants” or “dietary aides”, assist dietitians and other nutrition professionals to maintain nutritional care for patients and groups with special dietary needs. They assist in preparing food in hospitals, childcare centres, and aged care facilities.
Dietary aides in some countries might also carry out a simple initial health screening
for newly admitted patients in medical facilities, and inform the dietitian if any screened patients requires a dietitian’s expertise for further assessments or interventions.
Dietary clerks, also sometimes known as “medical diet clerks” or “dietary workers”, prepare dietary information for use by kitchen personnel in preparation of foods for hospital patients following standards established by a dietitian. They examine diet orders, prepare meal trays, maintain the storage area for food supplies, and ensure practice of sanitary procedures. They may operate computers to enter and retrieve data on patients’ caloric requirements and intake, or to track financial information. Dietary workers are typically trained on the job.
Dietary managers supervise the production and distribution of meals, as well as the budgeting and purchasing of food and the hiring, training and scheduling of support
staff in various types of workplaces offering larger scale food services, such as hospitals, nursing homes, school and college cafeterias, restaurants, correction facilities and catering services. They assure their department is compliant with food safety regulations, and that the food served meets dietary requirements established
by a dietitian.
Training requirements vary across jurisdictions and employment settings. Dietary management is not usually subject to professional regulation, although voluntary certification is preferred by many employers.
Dietary hosts/hostesses, also known as “food service aides”, assist in patient tray services in hospitals and other health care settings, usually under the supervision of the dietary manager. They distribute menus, and prepare, deliver and bring back meal trays. Usually no specific training is required for workers in this category.