Introduction for Nutrition Chapter 2

Example of Testimonials and anecdotes:

I lost 50 pounds in 30 days using this product. People usually receive payment for their endorsements. Reliable nutrition information is based on scientific evidence.

Who is the source?

Is the source a nutrition expert who has reliable credentials? Nutrition experts introduced or identified as "Doctor" may not be physicians or scientists. Their "doctoral" degree may be in a field that is unrelated to nutrition or a bogus degree purchased from the Internet.

What is the source?

Is the source scientific (evidence-based), such as an article from a peer-reviewed nutrition journal? Nutrition info in popular sources, such as magazines, generally has not been peer reviewed. Articles and programs that promote nutrition information may actually be sophisticated advertisements for nutrition-related products. Promoters may also refer to phony scientific journals to convince people that their information is reliable.

In 1914, the U.S> surgeon general assigned...

Joseph Goldberger, a physician to study pellagra. Most medical experts thought pellagra was an infectious disease because it often occurred where people lived in close quarters, such as prisons and orphanages.

Example of Attacks on conventional scientists and nutrition experts:

Medical researchers don't want you to know the facts." Such statements indicate unsupported biases against the scientific community.

Examples of promotes benefits while overlooking risks:

Our "all-natural supplements boost your metabolism naturally , so it won't harm your system." Anything a person consumes, even water, can be toxic in high doses. Consumers need to be wary of any source of information that fails that mention the possible side effects of using a dietary supplement or nutrition-related treatment.

Example of promises of quick and easy remedies:

Our product helps you lose weight without exercising or diet.

Cohort studies can be retrospective or prospective.

Retrospective means "to look back" and prospective means "to look forward" in time.

To evaluate various sources of nutrition information a person can ask many questions such as: What motivates the authors, promoters, or sponsors that provide the information?

What motivates the authors, promoters, or sponsors that provide the information? Who is the source? What is the source?

Example of disclaimers:

a disclaimer is a statement that modifies a claim or denies responsibility for it. For example, an ad for a weight-loss priduct claims, "Lose 30pounds in 30 days." However, the ad includes a disclaimer that is in small print and states, "Results not typical." Disclaimers are often clues that the product may not live up to consumers' expectations or the manufacturer's claims.

Despite the results of Dr. Goldberger's extraordinary experiment on himself...

a few physicians still resisted the idea that pellagra was associated with diet.

Then the scientists provide all study participants with the same instructions and...

a form of intervention, such as a dietary supplement or experimental food. However, only members of the treatment group actually receive the form of intervention that is being studied.

In a prospective cohort study...

a group of initially healthy people are followed over a time period and any diseases that eventually develop are recorded.

In a retrospective cohort study, researchers collect information about...

a group's past exposures and identify current health outcomes. Ex: nutrition epidemiologists might examine whether a group of people who have stomach cancer consumed more charcoal-broiled meat( the exposure) in the past than a group of people with similar characteristics who do not have stomach cancer.

Health experts often refrain from making quick judgements about...

a novel nutrition hypothesis until it undergoes repeated testing. Thus, it often takes many years before a scientific discovery becomes widely accepted by other experts in the nutrition field.

In addition to taking the required college coursework, the student dietitian must complete...

a supervised practice program that provides professional training in a health care facility such as a hospital, a food service company, or a community health care agency such as a state or local government health department.

Surveys often rely on people remembering details...

about their past lifestyle practices, which can be inaccurate or incomplete.

Consumers are responsible for questioning and researching the...

accuracy of nutrition information, as well as the credentials of the people making nutrition-related claims.

Even many websites using the .org domain suffix are...

actually sources of unreliable nutrition formation because they have a hidden agenda.

However, many people who drink alcohol also smoke cigarettes. If scientists did not..

adjust their results for their study population's use of tobacco, the results of their research may be weak or false.

People can find plenty of sites with nutrition information, including...

ads for dietary supplements, on the Internet. However, consumers must be careful and question the sources before accepting the information as being reliable.

An experiment that uses whole living organisms, such as mice is...

an in vivo experiment.

Additionally, Goldberger and one of his colleagues gave other...

an injection of blood from a person had pellagra. If pellagra were infectious, filth-party participants should have contracted the disease- but none of them did.

To conduct an online review of scientific literature, visit the U.S. National Library of Medicine and National Institutes of Health "PubMed" website. The site provides abstracts of...

and links to full-text articles about various medical conditions.

Medical researchers must be careful when applying the results of in vivo...

animal studies to people, because of the physiological differences between humans and other animals.

Therefore, all other conditions, including the amount of exercise the...

animals obtain and the extent of their handling by technicians, must be the same for both groups of mice.

In 1916, Dr. Goldberger decided to an experiment on himself and some volunteers during a "filth party". The group...

applied secretions taken from inside the nost and throat of a patient with pellagra to their noses and throats; they also swallowed pills made with flakes of skin scraped from the rashes of people with the disease.

RDNs plan dietary treatment (interventions), as well as...

appropriate and nutritious meals for hospitalized patients.

Free living subjects

are able to participate in studies without experiencing much disruption to their usual routines.

Placebos

are not just "sugar pills"; they are a sham (fake) treatment, such as a pill, injection, or medical procedure. The placebo mimics the treatment.

In many instances, people learn about the study's results when they....

are reported in an online news broadcast as a 15- or 30-second "sound bite". Such sources generally provide very little information concerning the way the study was conducted or how the data were collected and analyzed.

It is important to note that not every journal that has...

articles cited by PubMed is a reliable source of nutrition and health information

RDNs can also work as community nutritionists in public health settings or...

as directors of food service systems, such as cafeterias in hospitals and schools.

Dr. Goldberger died in 1929- 8years before Dr. Conrad Elvehjem and his team of scientists...

at the University of Wisconsin isolated a form of the vitamin niacin from liver extracts. They discovered that niacin cured "black tongue" a similar condition affecting dogs that was similar to pellagra.

However, epidemiologists can obtain much useful information...

concerning a population's typical dietary practices by conducting surveys of large numbers of people

Because of safety and ethical concerns, nutrition scientists often...

conduct experiments on small mammals ("animal models") before performing similar research on humans.

In many instances, however, it is not practical to...

conduct research on humans in laboratory settings, so scientists enroll subjects who are" free-living."

Even when investigating the same question, different groups or scientists often...

conduct their studies and analyze the results differently. For example, the numbers, ages, and physical conditions of the subjects; the type and length of the study; the amount of treatment provided; and the statistical tests used to analyze results typically vary among studies.

For example, a team of researchers is...

conducting a study involving human adults to test whether a dietary supplement that contains vitamin C is effective in shortening the duration of the common cold.

The scientists provide placebo pills to members of the...

control group that look, taste, and smell like the supplement pulls that contain vitamin C, which are provided for subjects in the treatment group.

If researchers design an experiment in which they fail to...

control variables that are not being tested, then their findings are likely to unclear, inaccurate, or questionable.

During their analysis, nutrition scientists often look for...

correlations (relationships) between variables and health outcomes.

Confounders are factors that were not being studied, but...

could have influenced the outcomes of the research. For ex: a group of scientists investigating the effects of alcohol consumption on bone health may determine that there is a positive relationship between the consumption of alcohol-containing beverages and risk of osteoporosis, a condition characterized by loss of bone tissue.

Nevertheless, scientists are often able to...

determine the safety and effectiveness of treatments by conducting research on laboratory animals before engaging in similar testing on humans.

During their analysis, nutrition scientists can...

determine whether their hypotheses are supported by the data.

Not long after Elvehjem's findings were published, niacin was...

determined to be effective in treating pellagra, and the medical establishment finally accepted the fact that the disease was the result of a dietary deficiency. Today, the idea that something missing in diets can cause a nutrient deficiency disease is widely accepted.

Consumers need to recognize that conflicting findings often result from...

differences in the ways various studies are designed.

Peer-reviewed journals usually require authors of articles to...

disclose their affiliations and sources of financial support. Such disclosures may appear on the first page or at the end of the article. By having this information, readers can decide on the reliability of the findings.

By conducting studies that explore differences in dietary practices and...

disease occurrences among populations, nutrition scientists may learn much about the influence of diet on health.

Scientists then try to identify links between exposures and...

diseases that occurred between the beginning and end of the study period.

When two different natural events occur simultaneously within a population, it...

does not necessarily mean they are related. What appears to be a correlation between a behavior and an outcome could be a coincidence, that is , a chance happening, and not an indication of a cause and effect relationship between the two variables.

Most people do not want to waste their money on things they...

don't need or that are useless or potentially harmful.

Over the following years, a group of medical researchers periodically collected data concerning...

each participant's health and, if the person died, the cause of death. Today, medical researchers are still collecting information from the original study participants, as well as their descendants.

One day, the news highlights dramatic health benefits from...

eating garlic, dark chocolate, brown rice, or cherries. A few weeks later, the news includes reports of more recent scientific investigations that do not support the earlier findings.

Although most registered dietitians work in health care settings, some RDNs are...

educators, researchers, or dietary counselors in private practice.

The scientists who have investigated the...

effects of consuming chemical X.

In a cohort study...

epidemiologists collect and analyze various kinds of information about a large group over time. The scientists are generally interested in making associations between exposure to a specific factor and the subsequent development of health conditions

To satisfy his critics, Goldberger enrolled a group of healthy Mississippi prison inmates in an...

experiment that involved consuming the corn-and molasses-based diet commonly eaten in the southern states at the time. After a few months, more than half of the inmates developed pellagra. Critics still rejected his findings.

At the beginning of study, over 5200 healthy participants (men and women) underwent...

extensive physical examinations and questioning about their family and personal medical histories, as well as their lifestyle practices.

If peers agree that a study was well conducted, its results are...

fairly represented, and the research is of interest to the journal's readers these scientists are likely to recommend that the journal's readers, these scientists are likely to recommend that the journal's editors publish the article.

If the information is simplistic and sensational, such as a....

finding that drinking green tea can result in weight loss, it is more likely to be reported in the popular media.

When analyzing their results, nutrition scientists who conduct studies on...

free-living groups of people must also consider the effects of confounders on their results.

The First Amendment of the U.S Constitution guarantees....

freedom of the press and freedom of speech, so people can provide nutrition information that is not true. Thus, the First Amendment does not protect consumers with freedom from nutrition misinformation or false nutrition claims.

Science involves asking questions, developing and testing hypotheses....

gathering and analyzing data, drawing conclusions from data, and sometimes, accepting change.

To obtain the RDN (or RD) credential, a person...

has to earn to least a bachelor's degree in an approved or accredited plan of study, such as "nutrition or dietetics major." at an accredited college or university in the United States.

The U.S> Food and Drug Administration (FDA) can regulate nutrition- and...

health related claims on product labels, but the agency cannot prevent the spread of health and nutrition misinformation published in books or on the Internet or presented in television or radio programs.

A clinical dietitian helps evaluate the...

health status of a patient and determines the patient's dietary deficiencies and needs.

People who use unconventional medical therapies, such as...

herbal products, to prevent or treat diseases often report that the products and treatments are effective, despite the general lack of scientific evidence to support their beliefs. Such personal reports (anecdotes) may be examples of the placebo effects.

Many state have licensure laws for someone using the title "nutritionist". In other states...

however, people can refer to themselves as "nutritionists" regardless of their education of training.

By analyzing the results of case-control studies, researchers...

identify factors that may have been responsible for the illness. For example, scientists may be able to identify dietary practices that differ between the two groups, such as long-term fruit and vegetable intakes.

Nevertheless, promoters of non-nutrient dietary supplements usually...

ignore the scientific evidence and continue to sell their goods to an unsuspecting, trusting public.

Concealing group membership is...

important during the course of an experiment because both researchers and subjects may try to predict group assignments based on their expectations

In the 1900s, pellagra was widespread in the U.S, especially...

in southern states.

Clinical dietitians can work as members of medical teams that...

include other health professionals, such as physicians, nurses, and physical therapists, in hospitals or clinics.

In a case-control study

individuals with a health condition (cases) such as heart disease or breast cancer are matched to persons with similar characteristics who do not have the condition (controls).

In the past, nutrition facts and dietary practices were often based on...

intuition, common sense, "conventional wisdom" (tradition), or anecdotes (reports of personal experiences). Today, nutrition experts base dietary recommendations on the results of scientific research

Most nutrition research involving humans is observational and...

involves either case-control study or cohort study designs.

An abstract

is a brief summary of an article that emphasizes key aspects of the research, that is the "take-away" messages.

A registered dietitian nutritionist (RDN) or registered dietitian (RD)

is a college-trained health care professional who has extensive knowledge of foods, nutrition, and dietetics, the application of nutrition and food information to achieve and maintain optimal health, and to treat many health-related conditions. The titles "registered dietitian nutritionist" and "registered dietitian" are legally protected and require certain credentials.

A registered dietitian nutritionist (RDN or RD)

is a health care professional who is " a food and nutrition expert."

Testimonial

is a personal endorsement of a product.

hypothesis

is a possible explanation for an observation that guides scientific research.

Experiment

is a systematic way of testing a hypothesis.

Pseudoscience

is the presentation of information masquerading as factual and scientific. Ex: "Learn how to combine certain foods based on your blood type", or "Most diseases are caused by undigested food that gets stuck in your guts. Promoters of nutrition misinformation often try to confuse people by weaving false information with facts into their claims, making the untrue material see credible, too.

If a person taking a placebo reports having negative effects, such as...

itching or headache, the response is called the nocebo effect

Universities and colleges that have nutrition or dietetics department are...

likely to employ nutrition experts, including instructors and researchers who have advanced degrees in foods, nutrition, and dietetics. Many of these faculty members are also registered dietitian nutritionists.

When consumers become confused and disappointed. As a result, some people...

may mistrust the scientific community and think nutrition scientists do not know what they are doing.

Goldberger hypothesized that the missing dietary factor was in...

meat, milk, and other foods eaten regularly by people with higher incomes.

Despite the results of Goldberger's experiment, many members of the...

medical establishment rejected his finding that a poor diet was the cause of pellagra.

To become a registered dietitian nutritionist, a person needs to...

meet specific educational and certification requirements that are approved by the Accreditation Council for Education in Nutrition and Dietetics (ACEND) of the Academy of Nutrition and Dietetics.

If the mice in the treatment group are as healthy as the...

mice in the control group at the end of this experiment, the researchers may conclude that the rodents can safely consume the amount of chemical X used in the study on a daily basis for a year.

For the duration of this study, the scientists examine the...

mice regularly for signs of health problem and record their results.

Therefore, sensational media coverage of a medical "breakthrough" is not...

necessarily an indication of the value or quality of research that resulted in the news story or magazine article.

To become more critical consumers of nutrition information, people...

need to be aware of red flags, clues that indicate a source of information is unreliable.

Human experimental studies are usually double blind; that is...

neither the investigators nor the subjects are aware of the subject's group membership, and this information is not revealed until the end of the study.

The results of one study are rarely enough to gain widespread acceptance for...

new or unusual findings or to provide a basis for nutritional recommendations. Thus, the findings obtained by one research team must be supported by those generated in other studies.

Therefore, when people report that a treatment was beneficial, they may...

not have been imagining the positive response, even when they were taking a placebo.

Nutrition researchers use a variety...

of statistical methods to analyze data (information) collected from observations and experiments. As a result, scientist can determine whether their hypotheses are supported by the data.

People can also located registered dietitian nutritionists by consulting...

online directories, contacting local dietetic associations or dietary departments of local hospitals, or visiting the Academy of Nutrition and Dietetics' website or the the Dietitians of Canada's website.

Many colleges and universities subscribe to a wide variety of...

online journals, enabling faculty and students to have free access to articles.

Information such as personal and family medical histories, eating habits, and..

other lifestyle behaviors is collected from each participant in the study.

Demographic are characteristics of a...

particular population that might affect health, such as income, age, and education level.

Before articles are accepted for publication, they undergo...

peer review, a critical analysis conducted by a group of "peers". Peers are investigators who were not part of the study but are experts involved in related research.

Dr. Goldberger also observed that...

people who did not develop pellagra had higher incomes and ate more meat, milk, and fresh vegetables. After considering this information, Goldberger developed the hypothesis that pellagra resulted from the lack of something in people's diet.

Researchers us findings from the NHANES to assess nutritional status of the...

population and determine the prevalence of major diseases and risk factors for diseases.

Even though a placebo contains inert ingredients, it may...

produce beneficial physiological and psychological changes, particularly in conditions that involve pain, extreme tiredness, nausea, or depression.

Such information is useful for educational programs designed to...

promote health and prevent disease. Medical experts also use the NHANES findings to establish national standards for assessing height, weight, and blood pressure.

Since its introduction in early 1960s, the National Health and Nutrition Examination Survey (NHANES) has...

provided information about the health and nutritional status of adults and children in the United States. This survey is unique because it combines interviews and physical examinations. The interview includes dietary, health-related, and demographic questions.

Certain kinds of mice and rats are...

raised for experimentation purposes, because the rodents are inexpensive to house in laboratories, and their food and other living conditions can be carefully controlled. Researchers must follow government guidelines concerning the ethical care and treatment of laboratory animals.

When conducting an experimental study involving human subjects, researchers usually...

randomly divide a large group of people into treatment (intervention) and control groups.

Because subjects in the control group think they are...

receiving a real treatment, their faith in the "treatment" can stimulate the release of chemicals in the brain that alter perception, reducing their discomfort.

An example of an inverse correlation is the...

relationship between fruit intake and hyperextension; as a population's fruit consumption increases, the percentage of people with hyperextension in that population decreases

Furthermore, researchers should evaluate and...

report their results objectively and honestly.

After the results of a study published in a nutrition-related journal or....

reported to health professionals attending a meeting of nutrition or medical society, the media (e.g. Internet news sources) may receive notice of the findings

In interventions studies involving humans, subjects may...

reports positive reactions to a treatment even though they received the placebo. This is the placebo effect.

Some funding sources can have certain expectations or biases about...

research outcomes, and as a result, they are likely to finance studies of scientists whose research efforts support their interests. The beef industry, for example, might not fund scientific investigations to find connections between high intakes of beef and the risk of certain cancers

These aspects of the process are important because personal biases can...

result in faulty findings or results that cannot be generalized to larger populations.

Individuals with pellagra have...

scaly skin sores, were weak, and developed diarrhea and mental confusion.

Health care professionals should refer to peer-reviewed...

scientific literature when searching for nutrition-related information.

To test their hypothesis using an animal model, the...

scientists divide 100 genetically similar, 3-week-old laboratory mice two groups of 50 mice.

Giving placebos to members of the control group enables..

scientists to compare the extent of the treatment's response with that of the placebo.

Therefore, it is important to...

search for information in more than one journal and compare research designs and results. Scientific journals that have long histories of publishing peer-reviewed articles are usually reliable sources.

Examples of Scare tactics:

sensational, frightening, false, or misleading statements about a food, dietary practice, or health condition, such as "Dairy products cause cancer"

If the results of several scientific investigations conducted under...

similar conditions confirm the original researchers' conclusions, then these findings are more likely to be accepted by other nutrition scientists

This historical event illustrates how researchers use scientific methods to...

solve medical mysteries relating to nutrition

The Fresh Tips box in this section presents...

some tips for using the Internet to obtain reliable nutrition information.

Scientists ask questions about the natural world and follow generally accepted...

standardized methods to obtain evidence-based answers to these questions.

If the investigators are aware of their subjects' individual group assignments during the...

study (a single-blind study), they may unwittingly convey clues to each subject's belief about being in the experimental or control group.

Scientists who want to determine the effect or effects of a single variable...

such as chemical X intake, need to control the influence of other variables.

When an experiment or study is completed and the results analyzed, researchers...

summarize the findings and seek to publish articles with information about their investigation in scientific journals.

In some cases, journals have been established and...

supported by groups with biases.

The science of nutrition is constantly evolving: Old beliefs and practices are discarded when they are not...

supported by more recent scientific evidence, and new principles and practices emerge from the new findings.

Much of the scientific research that is conducted in the United States is...

supported financially by the federal government, nonprofit foundations, and drug companies and other private industries.

On the other hand, the beef industry might be interested in...

supporting a team of scientists whose research indicates that a high-protein diet that contains plenty of beef is useful for people who are trying to lose weight.

To be careful consumers, people should not assume...

that all nutrition information presented in the popular media is reliable.

While investigating factors associated with pellagra, Goldberger observed...

that not everyone who was exposed to people suffering from pellagra developed the condition. Ex: many prisoners had pellagra, but the guards or prison administrators did not become infected with it.

Be wary of websites that are authored or sponsored by one person or...

that promote or sell products for profit (.com), because such sources of information may be biased.

In general, websites sponsored by nationally recognized health associations such as...

the Academy of Nutrition and Dietetics and nationally respected nonprofit organizations such as the National Osteoporosis Foundation are reliable sources of nutrition information.

Examples of peer-reviewed medical and nutrition journals include..

the Journal of Nutrition, American Journal of Clinical Nutrition, The New England Journal of Medicine, Journal of the American Medical Association, Nutrition Reviews, and Journal of the Academy of Nutrition and Dietetics.

Most nutrition-related research involving human subjects incorporates...

the basic steps of the scientific method.

Subjects who suspect they are in...

the control group and taking a placebo may report no changes in their condition because they expect a placebo should have no effect on them.

Beginning in 2024, people who want to become RDNs must meet...

the educational and supervised practice requirements as well as have a graduate degree before they will be qualified to take the registration examinination.

Random assignment helps ensure that...

the members of the treatment and control groups have similar variables, such as age and other characteristics.

If a patient believes a medical treatment will improve his or her health...

the patient is more likely to report positive results for the therapy.

The placebo pills, however, have inert ingredients; that is...

the pills contain substances that do not produce any measurable physical changes.

It is important to note that peers are not selected by...

the researchers who submit their papers for publication. Editors of scientific journals choose the experts, and the researchers are usually not aware the peers' identities.

Epidemiology

the study of the occurrence, distribution, and causes of health problems in populations.

Even today, scientists can have difficulty gaining the support of...

their colleagues for unusual ideas or solutions to problems.

Epidemiologists often use physical examinations of people to obtain health data. Additionally, they may collect info by conducting surveys which question people about...

their personal and family medical histories, diets, environmental exposures, health practices, and attitudes.

Additionally, individual genetic differences often contribute to a person's response to a treatment. Not only are people genetically different, but....

they also have different lifestyles, and they typically recall dietary information and follow instructions concerning health care practices differently. These and other factors can influence the results of nutrition research, especially studies involving human subjects.

A team of nutrition scientists for example, observes that people who eat high amounts of charcoal-grilled meat seem...

to have higher rates of stomach cancer than people who rarely eat grilled meat.

People cannot always rely on someone who refers...

to himself or herself as a "nutrition expert" or "nutritionals" for reliable nutrition information because there are no standard legal definitions for these descriptors.

Promoters of worthless nutrition-related products often...

use sophisticated marketing methods to lure consumers. For example, some promoters of dietary supplements claim their products are "scientifically tested", or they include citations for what appear to be scientific journal articles in their ads or articles. Consumers, however, cannot be certain this information is true.

Subjects in the control group are...

usually given a placebo.

Dr. Goldberger noted that prisoners ate a diet that...

was typically eaten by other people with pellagra. The diet emphasized corn bread, hominy grits (a corn product), molasses, potatoes, cabbage, and rice. At the time, this low-protein diet was associated with poverty throughout the southern US.

A correlation occurs when two variable change over the same period; for ex:

when a population's intake of sugar-sweetened soft drinks increases, the percentage of overweight people in the population also increases. This correlation is direct or positive, because the two variables (body weight and soft drink consumption) are changing in the same direction (increasing)

An inverse or negative correlation occurs...

when one variable increases and the other one decreases (the variables change in opposite directions).

Scientists expect other researchers to avoid relying on their personal attitudes and biases (points of view)....

when selecting participants for studies and collecting and analyzing data.

Epidemiological studies cannot establish causation; that is...

whether a specific practice is responsible for an effect (cause and effect).

Such journals provide a way of publishing articles that...

would be rejected by editors of reliable journals, because peer reviewers would indicate that the studies are poorly designed or have questionable findings.

Scientific method:

1. Make observations that generate questions 2. Formulate hypotheses to explain events 3. Review current scientific literature (published studies) that relate to the questions 4. Design studies, perform tests, and collect data. 5. Analyze data and draw conclusions based on the results 6. Share results with peers (report findings) 7. Conduct more research, the results of which may confirm or refute pervious findings.

Common red flags include the following:

1. Promises of quick and easy remedies 2. Claims that sound too good to be true. 3. Scare tactics 4. Attacks on conventional scientists and nutrition experts 5. Testimonials and anecdotes 6. Promotes benefits while overlooking risks 7. Vague, meaningless, or scientific-sounding terms 8. Vague sources 9. Pseudoscience 10. Disclaimers

The Framingham Heart Study that began in...

1949 in Framingham, Massachusetts, is one of the most well-known prospective studies.

Example of claims that sound too good to be true:

:Our all-natural product blocks fat and calories from being absorbed, so you can eat everything you like and still lose weight." Claims such as this are rarely true. If the claim sounds too good to be true, it probably is false.

Example of vague sources:

"Clinical research performed at a major university proves this revolutionary new dietary supplement cures diabetes." Which clinical study and at which "major university"

Example of vague, meaningless, or scientific-sounding terms:

"Our all-natural, scientifically tested, patented, chelated dietary supplement detoxifies your liver fast."

Be wary if the so-called nutrition expert has...

"credentials" that lack credibility among members of the scientific community, such as RNC ("registered nutrition consultant"), ND ("doctor of naturopathy"), CNC ("certificate in nutritional counseling"), and MH ("master herbalist").

Goldberger gave people meat milk, and other foods eaten regularly by people with higher incomes....

After he gave people these foods, they were cured of the disease.

What motivates the authors, promoters, or sponsors that provide the information?

Could they be more interested in helping people achieve better health and well-being or in selling their products?

Finally, this individual has to pass the national registration examination to...

become certified as an RDN. After this, RDNs are required to fulfill continuing education requirements to maintain their certification.

Few dietary supplements have been thoroughly evaluated by. reputable scientists. In some instances, these products have...

been scientifically tested, but the bulk of the research has shown that most dietary supplements, other than vitamins and minerals, provide little or no measurable health benefits.

Having a control group enables scientists to compare results...

between the two study groups to determine whether the treatment had any effect. Many variables can influence the outcome of an experimental study.

A variable is a factor, such as environment, that...

can change and influence an outcome.

Nutrition researchers also perform controlled laboratory experiments on...

cells or other components derived from living organisms. These studies are in vitro or "test tube" experiments.

Researchers feed the rodents in the treatment(or experimental) group a...

certain amount of chemical X daily for 52 weeks; the second group, the control group, does not receive the treatment during the period.

For decades, medical researchers have noted differences in rates of...

chronic diseases and causes of death among various human populations. Ex: type 2 diabetes, the most common type of diabetes, occurs more frequently among Pacific Islanders, Hispanic, and non-Hispanic African-American adults than among white American adults.