Questions and Answers
What is the main challenge for consumers when it comes to nutrition and health-related information?
To understand how scientists collect evidence about nutrition and health and to analyze this information to determine whether it is factual and based on scientific evidence or misinformation.
What was the basis of nutrition facts and dietary practices in the past?
Intuition, common sense, conventional wisdom, or anecdotes.
What do registered dietitian nutritionists (RDNs) and other nutrition experts do when the results of current scientific research no longer support conventional beliefs?
They discard conventional beliefs, explanations, and practices.
Why is it important to understand the scientific method in the context of nutrition and health?
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What is the primary goal of understanding the scientific method in nutrition and health?
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What is the difference between an evidence-based claim and an anecdotal claim?
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Why is it essential to analyze nutrition information to determine its reliability?
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What is the role of scientific research in nutrition and health?
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What is the primary goal of scientists when conducting research in the field of nutrition?
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What is the difference between in vivo and in vitro experiments?
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What is the purpose of a control group in an experimental study?
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What are the two main types of research that involve human subjects?
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Why is it important to control variables in an experimental study?
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What is the purpose of random assignment in an experimental study?
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What is the significance of reviewing published scientific studies before designing an experiment?
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Why do researchers need a large group of subjects in an RCT?
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What is the purpose of a placebo in an RCT?
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Why do nutrition scientists conduct laboratory experiments on small mammals before performing similar research on humans?
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What was the prevailing medical opinion about disease causes 100 years ago?
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What is a hypothesis in the context of scientific research?
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What is the role of data collection in an experimental study?
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Who observed that not everyone exposed to pellagra developed the condition?
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What did Dr. Goldberger note about the diet of prisoners with pellagra?
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Why do medical researchers need to be cautious when applying the results of in vivo animal studies to humans?
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What is the name of the disease that was widespread in the United States, especially in southern states, in the early 1900s?
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What is the scientific method, and how is it used in nutrition research?
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What is the term for a fake treatment used in an RCT?
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What is the main advantage of using a large group of subjects in an RCT?
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What was Dr. Goldberger's conclusion about the cause of pellagra?
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What was the typical diet associated with poverty in the southern United States during Dr. Goldberger's time?
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What did Dr. Goldberger do to test his dietary hypothesis?
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What was the result of Dr. Goldberger's experiment on healthy Mississippi prison inmates?
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What was the purpose of Dr. Goldberger's 'filth party' experiment?
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Who isolated niacin from liver extracts and discovered its connection to pellagra?
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What is the significance of double-blind studies in human experimental research?
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Why is maintaining secrecy important in human studies involving placebos?
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What is the potential problem with single-blind studies?
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Why did Dr. Goldberger's critics resist his findings about pellagra?
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What is the term for the phenomenon where people report positive or negative reactions to a real or sham treatment due to their expectations?
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What is the term for the number of people in a particular population who have a disease?
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What is the field of study that examines the occurrence, distribution, and causes of health problems in populations?
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What is the purpose of epidemiological studies?
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What is an example of a way epidemiologists collect data?
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Why is it important for subjects in a study not to know their group assignment?
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What is an example of a factor that may affect the results of a study?
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What is the term for the phenomenon where people's faith in a treatment can stimulate the release of chemicals in the brain that alter pain perception?
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Why do epidemiologists compare the living conditions of people with a certain health problem to those who are healthy?
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What is an example of a type of data that epidemiologists may collect during a study?
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What type of surveys do researchers use to assess the health and nutritional status of a nationally representative sample of Americans?
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What is a major challenge in determining the causes of chronic diseases such as heart disease and cancer?
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What is the primary goal of nutritional epidemiologists?
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What type of study design involves matching individuals with a health condition to persons with similar characteristics who do not have the condition?
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What is the difference between a retrospective and prospective cohort study?
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What is an example of a coincidental relationship, as described in the text?
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What type of information do researchers typically collect in a retrospective dietary study?
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What is the purpose of peer review in scientific publishing?
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What do observational epidemiological studies involve?
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Why is it important for scientists to avoid relying on their personal attitudes and biases when conducting research?
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What is the purpose of a case-control study?
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What is an example of research bias in the text?
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What is the advantage of a cohort study?
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What is an example of a historical instance of research bias, as described in the text?
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What is the goal of nutritional epidemiologists when conducting observational studies?
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What was the main shift in causes of death in the United States by the mid-20th century?
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Who were the two scientists who had different hypotheses concerning dietary causes of heart disease?
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What was the outcome of Yudkin's sugar hypothesis by the 1980s?
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Why is it important for nutrition researchers to use a variety of statistical methods to analyze data?
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What is the purpose of summarizing and publishing research findings in scientific journals?
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What was the Sugar Research Foundation (SRF) closely associated with?
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What did the Sugar Research Foundation (SRF) pay nutrition researchers to do in 1965-1966?
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Why do reliable scientific journals require authors to disclose their sources of funding?
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What is the purpose of peer review in nutrition journals?
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How can readers distinguish a peer-reviewed scientific journal from a popular magazine?
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Why do media outlets often report nutrition research findings as 'sound bites'?
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What is a potential problem with single-blind studies in human experimental research?
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Why is it important for readers to be cautious when evaluating nutrition information from popular sources?
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What is the purpose of disclosing affiliations and sources of financial support in peer-reviewed journals?
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Why do scientists emphasize positive research findings and minimize negative findings in some cases?
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What are some challenges associated with raising pigs for food in nomadic populations?
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Why might religious laws prohibiting pork consumption have developed in Islam and Judaism?
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What health concern may have contributed to the development of pork consumption taboos?
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In what region did Islam and Judaism originate, and how did this impact the practicality of raising pigs for food?
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What is likely to have been the main factor contributing to the development of dietary laws prohibiting pork consumption?
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How can consumers distinguish popular sources of nutrition information from peer-reviewed scientific journals?
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Why do sensational media coverage of a medical 'breakthrough' not necessarily indicate the value or quality of research?
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What contributes to conflicting findings in nutrition studies?
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How do individual genetic differences and lifestyle factors influence the results of nutrition research involving human subjects?
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What is the significance of food taboos in understanding nutrition and health?
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Why is it essential to analyze nutrition information to determine its reliability?
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What is the role of scientific research in nutrition and health?
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Why is it important to recognize that conflicting findings in nutrition research often result from differences in study design?
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What is the significance of replication in scientific research in the context of nutrition?
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What is the role of nutrition scientists in the evolution of nutrition knowledge?
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What is a limitation of epidemiological studies, and why is it important to consider this limitation?
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What is the main difference between retrospective and prospective cohort studies?
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What is an example of a direct correlation, and what does it indicate?
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What is the purpose of the Framingham Heart Study, and what was found?
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What is an inverse correlation, and what does it indicate?
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Why is it important to consider alternative explanations for observed correlations?
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What is a cohort study, and how does it differ from other types of epidemiological studies?
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What is the role of the investigators in a prospective cohort study?
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What is an example of a coincidence versus a true correlation?
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Why is it important to control for variables in epidemiological studies?
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What are the limitations of relying on a physician for nutrition advice?
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What are the benefits of consulting a registered dietitian (RD) or registered dietitian nutritionist (RDN) for nutrition information?
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How can you locate a registered dietitian nutritionist (RDN) in your area?
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What is the significance of the titles 'registered dietitian (RD)' and 'registered dietitian nutritionist (RDN)'?
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What are the three major professional divisions for registered dietitian nutritionists (RDNs)?
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What is the role of clinical dietitians?
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Why is it important to be cautious when seeking nutrition information from someone who calls themselves a 'nutritionist'?
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What is a reliable source of nutrition information?
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What is the primary role of food systems management dietitians?
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What is the minimum number of hours of supervised practice required for a student dietitian nutritionist?
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What is the purpose of a dietetic internship (DI)?
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What is required of RDNs to maintain their certification?
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In what settings can RDNs work as community nutritionists?
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What is the role of RDNs in corporate wellness programs?
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What is the role of RDNs in sports nutrition?
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What is the role of RDNs in the food and agriculture industry?
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What is the role of RDNs in universities?
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What is the role of RDNs in government agencies?
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Study Notes
Nutrition: Science for Consumers
- The scientific method involves making observations, generating questions, developing a hypothesis, and testing the hypothesis through experiments and data analysis.
- Nutrition scientists use the scientific method to determine the effects of dietary practices on health.
The Scientific Method
- The scientific method involves the following steps:
- Make observations
- Generate questions
- Develop a hypothesis
- Review literature
- Design an experiment
- Conduct the experiment
- Analyze data
- Draw conclusions
- Laboratory experiments, including in vitro and in vivo experiments, are used to test hypotheses.
- In vivo experiments use whole living organisms, such as mice, to test the effects of a variable, such as a chemical, on the body.
- In vitro experiments use cells or components derived from living organisms to test the effects of a variable in a controlled environment.
Animal Experimentation
- Animal experiments are used to test hypotheses and provide evidence-based information about nutrition.
- Experiments involve dividing animals into treatment and control groups to compare the effects of a variable.
- Control groups are necessary to compare the results of the treatment group to a baseline.
- Variables must be controlled to ensure accurate results.
Human Research: Experimental (Intervention) Studies
- Experimental studies involving human subjects are used to test the effects of dietary interventions on health.
- Researchers use randomized controlled trials (RCTs) to randomly assign participants to treatment or control groups.
- Placebos are used in control groups to mimic the treatment being tested.
- Double-blind studies are used to prevent bias, where neither the researchers nor participants know who is in the treatment or control group.
Human Research: Epidemiological Studies
- Epidemiological studies are used to understand the occurrence, distribution, and causes of health problems in populations.
- Epidemiologists use data collected from physical examinations, laboratory tests, and surveys to determine factors that affect health.
- Types of epidemiological studies include:
- Case-control studies: compare individuals with a health condition to those without the condition.
- Cohort studies: follow a group of people over time to observe the development of health conditions.
Placebo and Nocebo Effects
- The placebo effect is a positive response to a treatment or intervention due to expectations.
- The nocebo effect is a negative response to a treatment or intervention due to expectations.
- Placebos can produce real physiological and psychological changes, especially in conditions involving pain.
Importance of Evidence-Based Information
- Nutrition information derived from anecdotes and testimonials is not evidence-based.
- It is important to critically evaluate nutrition information and consider the source and quality of the evidence.
- Scientific research provides a reliable basis for understanding the relationships between nutrition and health.### Epidemiological Studies
- Case-control studies: compare people with a health condition (cases) to those without the condition (controls) to identify long-term dietary practices that may be associated with the development of the health problem
- Cohort studies: collect and analyze information about a large group of people over time to identify associations between exposure to a specific factor and the subsequent development of health conditions
- Retrospective cohort studies: collect information about a group's past exposures and identify current health outcomes
- Prospective cohort studies: follow a group of healthy people over time to record any diseases that develop and analyze the data to identify links between exposures and diseases
Limitations of Epidemiological Studies
- Cannot establish causation, only identify correlations between variables
- Correlations can be direct (positive) or inverse (negative)
- Correlations do not necessarily indicate a cause-and-effect relationship between variables
- Results can be influenced by research bias, funding sources, and personal attitudes
Analyzing Data and Drawing Conclusions
- Nutrition researchers use statistical methods to analyze data and identify relationships between variables and health outcomes
- Results are summarized and published in scientific journals, which undergo peer review before acceptance
- Peer review involves critical analysis by experts in related research fields to ensure the study was well-conducted and the results are fairly represented
Research Bias
- Scientists are expected to avoid personal biases and report results objectively and honestly
- Funding sources can influence research outcomes and expectations
- Disclosure of funding sources and potential conflicts of interest are important for maintaining research integrity
Spreading the News
- Peer-reviewed journals publish reliable, scientifically-scrutinized information
- Popular sources of nutrition information, such as magazines and the internet, may feature faulty or biased information
- It's important to distinguish between peer-reviewed journals and popular sources of nutrition information
Confusion and Conflict
- Conflicting results from different studies can cause confusion and mistrust of the scientific community
- Differences in study design, subject populations, and statistical analysis can contribute to conflicting results
- The science of nutrition is constantly evolving, and old beliefs and practices are discarded when not supported by new evidence
Food Taboos
- Food taboos are practices that prohibit the consumption of certain foods or beverages, often based on cultural or religious beliefs
- Food taboos can have no scientific basis, but are often cultural traditions passed down through generations
- Religions often incorporate food prohibitions into their laws of personal conduct, such as the prohibition of pork in Islam and Judaism
Reliable Nutrition Experts
- Not all individuals referring to themselves as "nutritionists" or "nutritionists" provide reliable information due to lack of standard legal definitions.
- Physicians are not always the best sources of nutrition information as most do not have extensive college coursework in nutrition.
- Reliable nutrition experts can be found in nutrition or dietetics departments of universities or colleges, including professors, registered dietitians, and registered dietitian nutritionists.
Registered Dietitian Nutritionists (RDNs)
- RDNs are college-trained health care professionals with extensive knowledge of foods, nutrition, and dietetics.
- The titles "registered dietitian (RD)" and "registered dietitian nutritionist (RDN)" are legally protected, requiring certification by the appropriate accrediting agency.
- RDNs can be located through online directories, local dietetic associations, hospitals, and the Academy of Nutrition and Dietetics or Dietitians of Canada websites.
Becoming a Registered Dietitian Nutritionist
- There are three professional divisions for RDNs: clinical dietetics, community nutrition, and food systems management.
- Clinical dietitians work in hospitals, clinics, or public health settings, while community nutritionists work in public health settings or as dietary counselors.
- Food systems management dietitians direct food service systems in hospitals, schools, and long-term care facilities.
- To become an RDN, one must complete a baccalaureate degree program approved by the Accreditation Council for Education in Nutrition and Dietetics (ACEND) of the Academy of Nutrition and Dietetics.
- RDNs must also complete at least 1200 hours of supervised practice (training) in a health care facility.
- Student dietitian nutritionists who don't have access to a supervised practice program can apply for a dietetic internship (DI) after graduation.
Career Paths for RDNs
- RDNs work primarily in hospitals or medical settings but can also find jobs in day-care centers, school districts, prisons, universities, corporations, pharmaceutical industries, sports nutrition, food and agriculture industries, universities, government agencies, media, and private practice.
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Description
Learn how nutrition scientists apply the scientific method to study the effects of dietary practices on health. Explore the steps involved in the scientific method.