Nutrition Chapter 2: Scientific Method

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Questions and Answers

What is the primary purpose of using the scientific method in nutrition science?

To prove conventional beliefs and practices

To design human studies without experimentation

To conduct animal experiments only

To discard conventional beliefs and practices that are not supported by evidence (correct)

What type of experiment is used to test a hypothesis in a controlled environment?

Animal observation

Clinical trial

Human research study

Laboratory experiment (correct)

Why are animal experiments used in nutrition science?

To test the effect of a treatment on a specific species only

To replace human studies entirely

To establish safety and efficacy before conducting human studies (correct)

To reduce costs associated with human research

What is the purpose of a placebo in an experimental study?

To control for variables and ensure that the treatment is the cause of any observed effects Signup and view all the answers

Why are large sample sizes needed in human research?

To account for variability among subjects Signup and view all the answers

What is the purpose of random assignment in experimental studies?

To ensure that the treatment and control groups are similar Signup and view all the answers

What is the primary characteristic of a randomized controlled trial (RCT)?

Subjects are randomly assigned to treatment and control groups Signup and view all the answers

What is the ultimate goal of using the scientific method in nutrition science?

To inform consumers about nutrition and health Signup and view all the answers

What is a concern about many health-related apps available to college students?

They have not been tested for effectiveness Signup and view all the answers

What should you do when searching for recipes online?

Check multiple sites for a recipe and compare the information Signup and view all the answers

What is a red flag indicating a questionable source of nutrition information?

Unrealistic or exaggerated claims Signup and view all the answers

What is a Registered Dietitian Nutritionist (RDN)?

A healthcare professional with extensive knowledge of foods, nutrition, and dietetics Signup and view all the answers

What is required to become a Registered Dietitian Nutritionist (RDN)?

A baccalaureate degree program approved by the Accreditation Council for Education in Nutrition and Dietetics Signup and view all the answers

Where can RDNs work?

In hospitals, day-care centers, school districts, prisons, long-term care facilities, and universities Signup and view all the answers

What is a dietary supplement?

A product that adds to a person's dietary intake Signup and view all the answers

What is conventional medicine?

Scientifically tested and evaluated health care practices Signup and view all the answers

Why may physicians not be the best sources of nutrition information?

They may not have extensive college coursework in nutrition Signup and view all the answers

What is the difference between a testimonial and an anecdote?

A testimonial is an endorsement from a person, and an anecdote is a personal experience or story Signup and view all the answers

How does the FDA regulate dietary supplements?

Manufacturers must notify the FDA and provide information about safety, but do not need FDA approval. Signup and view all the answers

What is a risk associated with using herbal supplements?

They may cause allergic reactions or interact with medications. Signup and view all the answers

Why is it important to consult a physician before using dietary supplements?

To determine if the supplement is necessary and to discuss potential interactions with medications. Signup and view all the answers

What is a potential hazard of using dietary supplements?

They may delay or replace medical treatment for serious diseases. Signup and view all the answers

What is a recommended source of information about dietary supplements?

U.S. National Library of Medicine. Signup and view all the answers

What should you do if you experience negative side effects after using a supplement?

Seek immediate medical attention. Signup and view all the answers

Why is it important to consume phytochemicals in their natural forms?

They provide a wider array of health benefits when consumed in whole foods. Signup and view all the answers

What is a characteristic of the dietary supplement industry in the United States?

It is a profitable industry, with Americans spending over $39 billion on supplements in 2019. Signup and view all the answers

Who should not take dietary supplements?

Healthy individuals. Signup and view all the answers

What is a recommended alternative to taking dietary supplements?

Consuming natural sources of nutrients and phytochemicals, such as fruits and vegetables. Signup and view all the answers

What is the primary function of epidemiological studies?

To identify factors that contribute to the development of health problems Signup and view all the answers

What type of study involves following a group of people over time to identify factors that contribute to the development of a health condition?

Cohort study Signup and view all the answers

What is the term for a negative response to a treatment due to expectation?

Nocebo effect Signup and view all the answers

What is the primary limitation of epidemiological studies?

They cannot establish causation Signup and view all the answers

What is the purpose of peer review in research?

To ensure the study was well-conducted and the results are fairly represented Signup and view all the answers

What type of correlation occurs when two variables are associated with a third variable, rather than with each other?

Coincidental correlation Signup and view all the answers

What is an example of research bias?

The beef industry funding a study on the benefits of beef consumption Signup and view all the answers

Why may conflicting results occur in research studies?

All of the above Signup and view all the answers

What is the primary advantage of peer-reviewed articles?

They are more reliable than popular sources of nutrition information Signup and view all the answers

What is a reason why there is so much nutrition misinformation?

Promoters of nutrition-related products may use sophisticated marketing methods Signup and view all the answers

What should you do when evaluating a product's effectiveness?

Check the source of the information and evaluate the motivations of the authors Signup and view all the answers

What is a red flag to look out for when evaluating nutrition information?

Promises of quick and easy remedies for complex health problems Signup and view all the answers

What is a characteristic of a reliable online source of nutrition information?

The website is sponsored by a nationally recognized health association Signup and view all the answers

What can you use to search for science-based published articles?

PubMed Signup and view all the answers

What is a role of the Federal Trade Commission (FTC)?

To enforce consumer protection laws and investigate complaints Signup and view all the answers

What should you be cautious of when evaluating websites sponsored by nationally recognized health associations?

They may promote or sell products for profit Signup and view all the answers

What is a characteristic of a potentially misleading website?

The website provides vague or meaningless terms Signup and view all the answers

Why should you use multiple sites when searching for nutrition information online?

To evaluate the credibility of different sources Signup and view all the answers

What should you do when using mobile apps for health and nutrition?

Evaluate the app's credibility and sources Signup and view all the answers

Study Notes

The Scientific Method in Nutrition

The scientific method involves making observations, generating questions, developing a hypothesis, reviewing literature, designing an experiment, collecting and analyzing data, and drawing conclusions.
Nutrition scientists use the scientific method to discard conventional beliefs and practices that are not supported by evidence.

Laboratory Experiments

Laboratory experiments involve testing a hypothesis using a systematic approach.
Animal experiments (in vivo) and cell-based experiments (in vitro) are used to test hypotheses.
Animal experiments are used to establish safety and efficacy before conducting human studies.

Human Research: Experimental (Intervention) Studies

Experimental studies involve randomly assigning human subjects to treatment and control groups.
Randomized controlled trials (RCTs) are used to test hypotheses.
Placebos are used to control for variables and ensure that the treatment is the cause of any observed effects.

Characteristics of Human Research

Human research involves variability among subjects, which can affect the results of the study.
Large sample sizes are needed to account for this variability.
Random assignment helps to ensure that the treatment and control groups are similar.

Randomized Controlled Trials (RCTs)

RCTs are used to test hypotheses in human research.
Subjects are randomly assigned to treatment and control groups.
Placebos are used to control variables.

Placebo and Nocebo Effects

The placebo effect is a positive response to a treatment due to expectation.
The nocebo effect is a negative response to a treatment due to expectation.
Placebos can produce beneficial physiological and psychological changes.

Human Research: Epidemiological Studies

Epidemiological studies involve the study of the occurrence, distribution, and causes of health problems in populations.
These studies are used to identify factors that affect the health of a population.
Data are collected from physical examinations, laboratory tests, and surveys.

Types of Epidemiological Studies

Case-control studies compare individuals with a health condition (cases) to individuals without the condition (controls).
Cohort studies involve following a group of people over time to identify factors that contribute to the development of a health condition.

Importance of Epidemiological Studies

Epidemiological studies help to identify factors that contribute to the development of health problems.
They inform public health policy and prevention strategies.
They provide a basis for further research into the causes of health problems.

Epidemiology and Study Designs

Epidemiology is the study of the distribution and determinants of health-related events or characteristics among populations.
Epidemiological studies involve observing and analyzing large groups of people to identify patterns and correlations between variables and health outcomes.

Case-Control Study

A case-control study involves matching people with a health condition (cases) with people who are healthy (controls) but have similar characteristics.
The goal is to identify differences in exposures or behaviors between the two groups that may be associated with the development of the health condition.

Cohort Study

A cohort study involves collecting and analyzing data on a large group of people over time.
The study can be retrospective or prospective.
Retrospective cohort study: collects data on past exposures and current health outcomes.
Prospective cohort study: collects data on exposures at the beginning of the study and follows participants over time to record health outcomes.

Limitations of Epidemiological Studies

Epidemiological studies cannot establish causation, only correlation.
Correlation occurs when two variables change over the same period.
Types of correlation: direct (positive), inverse (negative), and coincidental.
Coincidental correlations occur when two variables are associated with a third variable, rather than with each other.

Analyzing Data and Drawing Conclusions

Nutrition researchers use statistical methods to analyze data and identify relationships between variables and health outcomes.
Researchers must avoid research bias and report results objectively and honestly.
Peer review is a critical analysis of research conducted by experts in the field to ensure the study was well-conducted and the results are fairly represented.

Research Bias

Research bias occurs when funding sources or personal attitudes influence the results of a study.
Examples of research bias: the beef industry funding studies that support the benefits of beef consumption, or the sugar industry influencing research to downplay the role of sugar in heart disease.

Peer-Reviewed Articles

Peer-reviewed articles are published in scientific journals and have undergone critical analysis by experts in the field.
Examples of peer-reviewed medical and nutrition journals: Journal of the Academy of Nutrition and Dietetics, The New England Journal of Medicine, Journal of the American Medical Association.
Peer-reviewed articles are more reliable than popular sources of nutrition information, such as magazines and internet sources.

Confusion and Conflict

Conflicting results can occur due to differences in study design, population, and analysis.
Genetic differences, lifestyle, and individual responses to treatments can also contribute to conflicting results.
The science of nutrition is constantly evolving, and new findings can lead to changes in practices and recommendations.

Nutrition Information: Fact or Fiction

Misinformation can come from popular magazine articles, best-selling books, or TV programs.
The First Amendment protects freedom of speech and press, but not freedom from misinformation.
Promoters of nutrition-related products may use sophisticated marketing methods to lure consumers.

Becoming a Critical Consumer of Nutrition Information

Be wary of testimonials and anecdotes as proof of a product's effectiveness.
Check the source of the information: is it scientific, peer-reviewed, and based on human studies?
Evaluate the motivations of the authors, promoters, or sponsors: are they more interested in your health or selling a product?
Check for red flags, such as promises of quick fixes, scare tactics, and personal attacks on scientists.

Red Flags to Look Out For

Promises of quick and easy remedies for complex health problems.
Claims that sound too good to be true.
Scare tactics, such as sensational or misleading statements about a food or health condition.
Personal attacks on the motives and ethical standards of registered dietitian nutritionists or conventional scientists.
Statements about the superiority of certain dietary supplements or unconventional medical practices.
Testimonials and anecdotes as evidence of effectiveness.
Information that promotes a product's benefits while overlooking its risks.
Vague, meaningless, or scientific-sounding terms to impress or confuse consumers.
Sensational statements with incomplete references or sources.
Recommendations based on a single study.
Results disclaimers, usually in small or difficult-to-read print.

Evaluating Online Sources of Nutrition Information

Be cautious of websites that promote or sell products for profit (*.com).
Look for websites sponsored by nationally recognized health associations (.org) and government agencies (.gov).
Use multiple sites, especially government sites, as well as the sites of nationally recognized nutrition- or health-related associations.
Use PubMed as a resource when searching for science-based published articles.
Rely primarily on sites that are managed or reviewed by qualified health professionals.
Look for the HONcode symbol at the bottom of the main page of the website.
Do not trust information at a site that does not indicate valid sources, such as well-respected peer-reviewed scientific journals or nationally recognized medical centers.

Federal Trade Commission (FTC)

Enforces consumer protection laws and investigates complaints about false or misleading health claims on the Internet.
Provides information to help evaluate nutrition and health-related claims on its website (www.consumer.ftc.gov/articles/0167-miracle-health-claims).
Allows consumers to submit complaints through an online form or call the toll-free line (1-877-382-4357).

Mobile Apps for Health and Nutrition

In 2018, 89% of undergraduate U.S. college students had access to smartphones.
Thousands of apps available to monitor and improve diets, energy intakes, physical activity levels, and other health-related behaviors.
Many apps have not been tested for effectiveness, so it's essential to search online for reliable reviews and ratings before using them.

Food and Nutrition Tips

The Internet provides access to numerous recipes and cooking tips from various countries and ethnic groups.
When searching for recipes, recognize that food manufacturers may promote their products in recipes.
Be cautious when using recipes online, as they may not provide accurate nutrition information or have been tested for quality.
It's a good idea to check multiple sites for a recipe and compare the information.

Concept Checkpoint

A testimonial is a statement or endorsement from a person, whereas an anecdote is a personal experience or story.
Red flags indicating a questionable source of nutrition information include:
- Unrealistic or exaggerated claims.
- Lack of scientific evidence or research.
- Unqualified or biased sources.

Tips for using the Internet as a reliable source of nutrition information include:

Verify information through reputable sources.
Check for scientific evidence and research.
Evaluate the credibility of the source.

Identifying Reliable Nutrition Experts

Not all individuals who call themselves "nutritionists" or "nutritionists" can provide reliable nutrition information due to lack of standard legal definitions.
Physicians are not necessarily the best sources of nutrition information because they may not have extensive college coursework in the subject.
Registered Dietitian Nutritionists (RDNs) are college-trained healthcare professionals with extensive knowledge of foods, nutrition, and dietetics.

Becoming a Registered Dietitian Nutritionist

RDNs 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.
The program includes a wide variety of college-level courses, such as food and nutrition sciences, organic chemistry, biochemistry, anatomy, physiology, microbiology, statistics, management, and communications.
RDNs must also obtain at least 1200 hours of

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Description

Learn about the application of the scientific method in nutrition and health to inform consumers. Understand the steps involved in the scientific method and its importance in nutrition science.