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Audire dissentiunt mediocritatem an nam, at erat accumsan usu, volutpat petentium suavitate ei nam. Distribution, posting, or copying of this PDF is strictly prohibited without written. Obesity Assessing Prevalence and Geography She also highlighted Strategies to Limit In light of new After talking with a large number of clients, you notice a pattern developing in that the clients who report being more physically active are also those having lower blood pressure readings.
This observation leads you to question the relationship that might exist between physical activity and blood pressure. Your next step is to develop a hypothesis, or possible explanation for your observation.
A Hypothesis Is a Possible Explanation for an Observation A hypothesis is also sometimes referred to as a research question.
In other words, it must be testable. An Experiment Is Designed to Test the Hypothesis An experiment is a scientific study that is conducted to test a hypothesis. For example, would you be more likely to believe a study that tested 5 people or ? Having a control group is essential for comparison between treated and untreated individuals.
A control group is a group of people who are as much like the treated group as possible except with respect to the variable being tested. For instance, in your study, 45 minutes daily of aerobic exercise would be the variable; the experimental group would consist of people over age 65 with high blood pressure who perform the exercise, and the control group would consist of people of the same age with high blood pressure who do not exercise.
Using a control group helps a researcher to judge if a particular treatment has worked or not. A good experimental design also attempts to control for other variables that may coincidentally influence the results. For example, what if someone in your study was on a diet, smoked, or took blood-pressure-lowering medication?
Because any of these factors could affect the results, researchers try to design experiments that have as many constants as possible. In doing so, they increase the chance that their results will be valid. For example, in your study the data being collected are blood pressure readings. These values could be collected by a person or a machine, but because the data will be closely scrutinized by other scientists, they should be as accurate as technology allows.
In this case, an automatic blood pressure gauge would provide more reliable and consistent data than blood pressure measurements taken by research assistants. Once the data have been collected, they must be interpreted or analyzed. Often, the data will begin to make sense only after being organized and put into different forms, such as tables or graphs, that reveal patterns that at first were not obvious. In your study, you can create a graph comparing blood pressure readings from both your experimental group and your control group to see if there is a significant difference between the blood pressure readings of those who exercised and those who did not.
Most Hypotheses Need to Be Refined Remember that a hypothesis is basically a guess as to what causes a particular phenomenon. Rarely do scientists get it right the first time. The original hypothesis is often refined after the initial results are obtained, usually because the answer to the question is not clear and leads to more questions. When this happens, an alternative hypothesis is proposed, a new experiment is designed, and the new hypothesis is tested.
Ideally, multiple experiments are conducted over many years to thoroughly test a hypothesis. Indeed, repeatability is a cornerstone of scientific investigation. Supporters and skeptics alike must be able to replicate an experiment and arrive at similar conclusions or the hypothesis becomes invalid. Have you ever wondered why the measurements used in scientific textbooks are always in the metric system? The answer is repeatability. Scientists use the metric system because it is a universal system and thus allows repeatability in any research facility worldwide.
Unfortunately, media reports on the findings of a research study that has just been published rarely include a thorough review of the other studies conducted on that topic. Thus, you should never accept one report in a newspaper or magazine as absolute fact on any topic.
A Theory May Be Developed Following Extensive Research If the results of multiple experiments consistently support a hypothesis, then scientists may advance a theory. A theory represents a scientific consensus agreement as to why a particular phenomenon occurs. Although theories are based on data drawn from repeated experiments, they can still be challenged and changed as the knowledge within a scientific discipline evolves.
For example, at the beginning of this chapter, we said that the prevailing theory held that beriberi was an infectious disease. Experiments were conducted over several decades before their consistent results finally confirmed that the disease was due to thiamin deficiency. We continue to apply the scientific method to test hypotheses and challenge theories today. RecaP The steps in the scientific method are 1 observing a phenomenon, 2 creating a hypothesis, 3 designing and conducting an experiment, and 4 collecting and analyzing data that support or refute the hypothesis.
If the data are rejected, then an alternative hypothesis is proposed and tested. If the data support the original hypothesis, then a conclusion is drawn. A hypothesis that is supported after repeated experiments may be called a theory.
Different Types of Research Studies Tell Us Different Stories Establishing nutrition guidelines and understanding the role of nutrition in health involve constant experimentation.
Depending upon how the research study is designed, we can gather information that tells us different stories. Epidemiological Studies theory A scientific consensus, based on data drawn from repeated experiments, as to why a phenomenon occurs.
Epidemiological studies are also referred to as observational studies. They involve assessing nutritional habits, disease trends, or other health phenomena of large populations and determining the factors that may influence these phenomena. However, these studies can only indicate relationships between factors, not specifically a cause-and-effect relationship. All these results can tell us is that there is a relationship between higher physical activity and lower blood pressure in older adults.
Model Systems Humans are not very good experimental models because it is difficult to control for all of the variables that affect their lives. Humans also have long life spans, so it would take a long time to determine the effects of certain nutritional studies. For these reasons, laboratory studies generally involve experiments with animals. In many cases, animal studies provide preliminary information that can assist us in designing and implementing human studies.
Animal studies also are used to conduct research that cannot be done with humans. For instance, it is possible to study nutritional deficiencies in animals by causing a deficiency and studying its adverse health effects over the life span of the animal; this type of experiment is not acceptable to perform with humans. Animals with relatively short reproduction times can be studied when researchers need to look at the effects of specific drugs or treatments over many generations.
Such animals can also be bred so they display specific traits such as certain diseases or metabolic conditions. One drawback of animal studies is that the results may not apply directly to humans. Human Studies The two primary types of studies conducted with humans include case control studies and clinical trials.
Case control studies are epidemiological studies done on a smaller scale. Case control studies involve comparing a group of individuals with a particular condition for instance, older adults with high blood pressure to a similar group without this condition for instance, older adults with low blood pressure.
This comparison allows the researcher to identify factors other than the defined condition that differ between the two groups. By identifying these factors, researchers can gain a better understanding of things that may cause and help prevent disease.
In the case of your experiment, you may find that older adults with low blood pressure are not only more physically active, but also eat more fruits and vegetables and less sodium. These findings would indicate that other factors in addition to physical activity may play a role in affecting the blood pressure levels of older adults. Clinical trials are tightly controlled experiments in which an intervention is given to determine its effect on a certain disease or health condition.
Interventions may include medications, nutritional supplements, controlled diets, or exercise programs. Clinical trials include the experimental group, whose members are given the intervention, and the control group, whose members are not given the intervention.
The responses of the intervention group are compared to those of the control group. In the case of your experiment, you could assign one group of older adults with high blood pressure to an exercise program and assign a second group to a program in which no exercise is done. After the intervention phase was completed, you could compare the blood pressure of the people who exercised to those who did not. If the blood pressure of the intervention group decreased significantly and the blood pressure of the control group did not, then you could propose that the exercise program caused a decrease in blood pressure.
Among clinical trials, the type considered most likely to produce valid, reliable data is the double-blind, placebo-controlled study. In a double-blind study, neither researchers nor participants know which group is really getting the treatment. Blinding helps prevent the researchers from seeing only the results they want to see. A placebo is an imitation treatment that has no scientifically recognized therapeutic value, for instance, a sugar pill that looks, feels, smells, and tastes identical to the medication being tested.
In a double-blind, placebo-controlled study, neither the researchers providing the treatment nor the study participants receiving it know whether the treatment being administered is the one being tested or a placebo. Epidemiological studies indicate relationships between factors, such as between exercise and blood pressure in older adults, but cannot prove cause and effect.
This is known as the psychosomatic effect or placebo effect. For example, because the older adults in your study know they are part of a study concerning high blood pressure, they may subconsciously be more relaxed and content because they feel validated and important.
They may therefore show a decrease in blood pressure. Use Your Knowledge of Research to Help You Evaluate Media Reports How can all of this research information assist you in becoming a better consumer and critic of media reports? By having a better understanding of the research process and types of research conducted, you are more capable of discerning the truth or fallacy within media reports. If the report is made by a person or group who may financially benefit from you buying their products, you should be skeptical of the reported results.
Also, many people who write for popular magazines and newspapers are not trained in science and are capable of misinterpreting research results.
Who conducted the research, and who paid for it? Was the study funded by a company that stands to profit from certain results? Are the researchers receiving goods, personal travel funds, speaking fees, or other perks from the research sponsor, or do they have investments in companies or products related to their study?
If the answer to any of these questions is yes, there exists a conflict of interest between the researchers and the funding agency. To become a more informed critic of nutrition reports in the media, and a smarter consumer, you need to understand the research process and how to interpret the results of different types of studies. Ideally, the journal is peer-reviewed; that is, the articles are critiqued by other specialists working in the same scientific field.
A reputable report should include the reference, or source of the information, and should identify researchers by name. This allows the reader to investigate the original study and determine its merit. Some reputable nutrition journals are identified later in this chapter. Is the report based on testimonials about personal experiences? Are sweeping conclusions made from only one study? Be aware of personal testimonials, as they are fraught with bias. In addition, one study cannot answer all of our questions or prove any hypothesis, and the findings from individual studies should be placed in their proper perspective.
Are the claims in the report too good to be true? Are claims made about curing disease or treating a multitude of conditions? If something sounds too good to be true, it probably is. Claims about curing diseases or treating many conditions with one product should be a signal to question the validity of the report.
As you may know, quackery is the misrepresentation of a product, program, or service for financial gain. Marilyn, the woman with high blood pressure from our opening story, was a victim of quackery. She probably would not have purchased that weight-loss supplement if she had understood that it was no more effective in promoting weight loss than a generic fiber supplement costing less than half the price.
Throughout this text we provide you with information to assist you in becoming a more educated consumer regarding nutrition. You will learn about labeling guidelines, the proper use of supplements, and whether various nutrition topics are myths or facts. Armed with the information in this book, plus plenty of opportunities to test your knowledge, you will become more confident when trying to evaluate nutrition claims.
RecaP Epidemiological studies involve large populations, model studies involve animals, and human studies include case control studies and clinical trials. Each type of study can be used to gather a different kind of data. When evaluating media reports, consider who is reporting the information, who conducted and paid for the research, whether or not the research was published in a reputable journal, and whether it involves testimonials or makes claims that sound too good to be true.
Quackery is the misrepresentation of a product, program, or service for financial gain. After reading this chapter, you can see that nutrition is a relatively new science that plays a critical role in preserving health and preventing and treating disease.
As recognition of this vital role has increased over the past few decades, the public has become more and more interested in understanding how nutrition affects their health.
One result of this booming interest has been the publication of an almost overwhelming quantity of nutritional information and claims on television infomercials; on Web sites; in newspapers, magazines, newsletters, and journals; on product packages; and via many other forums. Nutrition professionals are in a perfect position to work in a multitude of settings to counsel and educate their clients and the general public about sound nutrition practices.
The following discussion identifies some key characteristics of reliable sources of nutrition information. Trustworthy Experts Are Educated and Credentialed It is not possible to list here all of the types of health professionals who provide reliable and accurate nutrition information. RDs are qualified to work in a variety of settings.
Individuals who complete the education, experience, exam, and registration are qualified to provide nutrition counseling in a variety of settings.
For a list of individuals who are registered dietitians in your community, you can look in the yellow pages of your phone book or contact the American Dietetic Association at www. Licensed dietitian: A licensed dietitian is a dietitian meeting the credentialing requirement of a given state in the United States to engage in the practice of dietetics. These laws specify which types of licensure or registration a nutrition professional must obtain in order to provide nutrition services or advice to individuals.
Individuals who practice nutrition and dietetics without the required license or registration can be prosecuted for breaking the law. Nutritionist: This term generally has no definition or laws regulating it.
In some cases, it refers to a professional with academic credentials in nutrition who may also be an RD. There is no guarantee that a person calling himself or herself a nutritionist is necessarily educated, trained, and experienced in the field of nutrition. It is important to research the credentials and experience of any individual calling himself or herself a nutritionist. For instance, they may teach at community colleges or universities or work in fitness or healthcare settings.
Unless these individuals are licensed or registered dietitians, they are not certified to provide clinical dietary counseling or treatment for individuals with disease. However, they are reliable sources of information about nutrition and health.
Physician: The term physician encompasses a variety of healthcare professionals. A medical doctor MD is educated, trained, and licensed to practice medicine in the United States. However, MDs typically have very limited experience and training in the area of nutrition. Medical students in the United States are not required to take any nutrition courses throughout their academic training, although some may take courses out of personal interest.
On the other hand, a number of individuals who started their careers in nutrition go on to become medical doctors and thus have a solid background in nutrition. Nevertheless, if you require a dietary plan to treat an illness or disease, most medical doctors will refer you to an RD or licensed nutritionist.
In contrast, an osteopathic physician, referred to as a doctor of osteopathy DO , may have studied nutrition extensively, as may a naturopathic physician, a homeopathic physician, or a chiropractor. Government Sources of Information Are Usually Trustworthy Many government health agencies have come together in the past 20 years to address the growing problem of nutrition-related disease in the United States.
Thus, these agencies have the resources to organize and disseminate the most recent and reliable information related to nutrition and other areas of health and wellness. A few of the most recognized and respected of these government agencies are discussed here. Located in Atlanta, Georgia, the CDC works in the areas of health promotion, disease prevention and control, and environmental health. Among its many activities, the CDC supports two large national surveys that provide us with important nutrition and health information.
The NHANES tracks the nutrient consumption of Americans and includes carbohydrates, lipids, proteins, vitamins, minerals, fiber, and other food components. Nutrition and other health information is gathered from interviews and examinations using hour dietary recalls, food-frequency questionnaires, and dietary interviews. The database for the NHANES survey is extremely large, and an abundance of research papers have been generated from it.
The mission of the NIH is to uncover new knowledge that leads to better health for everyone. This mission is accomplished by supporting medical research throughout the world and by fostering communication of this information. The NIH has many institutes and centers that focus on a broad array of nutrition-related health issues. Lifestyle behaviors, such as eating an unhealthful diet, can increase your risk for chronic disease.
Its mission is to promote health and quality of life by preventing and controlling disease, injury, and disability. Professional Organizations Provide Reliable Nutrition Information A number of professional organizations represent nutrition professionals, scientists, and educators.
These organizations publish cutting-edge nutrition research studies and educational information in journals that are accessible at most university and medical libraries. The mission of this organization is to promote nutrition, health, and well-being.
The Canadian equivalent is Dietitians of Canada. The ASN fulfills its mission by fostering, enhancing, and disseminating nutrition-related research and professional education activities.
The primary goals of the SNE are to educate individuals, communities, and professionals about nutrition education and to influence policy makers about nutrition, food, and health. The mission of the ACSM is to advance and integrate scientific research to provide educational and practical applications of exercise science and sports medicine.
Many members are nutrition professionals who combine their nutrition and exercise expertise to promote health and athletic performance. It is committed to encouraging research on the causes and treatments of obesity and to keeping the medical community and public informed of new advances.
The official NAASO journal is Obesity Research, which is intended to increase knowledge, stimulate research, and promote better treatment of people with obesity. For more information on any of these organizations, see the Web Links at the end of this chapter. The National Institutes of Health is the leading medical research agency in the world. They had a report about this study that had just come out saying that ballet dancers are at some super-abnormally high risk for fractures! Identify at least two factors she should evaluate.
Fill it out as carefully and thoroughly as you can, listing each food you ate yesterday, beginning and ending at midnight. Now answer the following questions: 1. How confident are you that you documented every single item that you ate all day yesterday? How confident are you that you recalled accurately the serving size of each food you ate? Given your experience filling out a hour dietary recall, what would you identify as the main limitations of this assessment tool?
More precisely, a kilocalorie is the 2 3 T F 4 F 5 F amount of heat required to raise the temperature of 1 kilogram of water by 1 degree Celsius. Carbohydrates and lipids are the primary energy sources for the body. Most water-soluble vitamins need to be consumed daily. However, we can consume foods that contain fat-soluble vitamins less frequently because our bodies can store these vitamins.
Other good sources are professional organizations in the field of nutrition research and education and individuals who are licensed or registered as nutrition professionals. Specific dietary intake tools include a diet history, hour recalls, food-frequency questionnaires, and diet records.
As the Western diet improved, obesity and its associated chronic diseases became an important subject for nutrition research. In the late 20th century, nutrigenomics emerged as a new field of nutrition research.
Healthful nutrition plays a critical role in eliminating deficiency disease and can help reduce our risks for various chronic diseases.
A primary nutrient deficiency occurs when a person does not consume enough of a given nutrient in the diet. A secondary nutrient deficiency occurs when a person cannot absorb enough of a nutrient, when too much of a nutrient is excreted, or when a nutrient is not efficiently utilized. The steps in the scientific method are 1 observing a phenomenon, 2 creating a hypothesis, 3 designing and conducting an experiment, and 4 collecting and analyzing data that support or refute the hypothesis.
Epidemiological studies involve large populations, model studies involve animals, and human studies include case control studies and clinical trials. A double-blind, placebo-controlled study is considered the most trustworthy form of clinical trial. Medical professionals such as physicians, osteopaths, and registered nurses have variable levels of training in nutrition. Carbohydrates are the primary energy source for the human body, particularly for the brain.
Proteins support tissue growth, repair, and maintenance. The mission of NIH is to uncover new knowledge that leads to better health for everyone. Undernutrition occurs when someone consumes too little energy or nutrients, and overnutrition occurs when too much energy or too much of a given nutrient is consumed over time. Vitamins A and C, thiamin, calcium, and magnesium are considered a. Malnutrition plays a role in which of the following?
Ten grams of fat a. Which of the following assessment methods provides objec- tive data? Which of the following statements about hypotheses is true? Hypotheses can be proven by clinical trials. If the results of multiple experiments consistently support a hypothesis, it is confirmed as fact. True or false? Fat-soluble vitamins provide energy. Carbohydrates, lipids, and proteins all contain car- bon, hydrogen, and oxygen.
The Recommended Dietary Allowance represents the average daily intake level that meets the requirements of almost all healthy individuals in a given life stage or gender group. An epidemiological study is a clinical trial in which a large population participates as members of the experimental and control groups.
Nutrition-related reports in the Journal of the American Dietetic Association are likely to be trustworthy. Explain the role of the control group in a clinical trial. Imagine that you are in a gift shop and meet Marilyn, from the chapter-opening scenario. She has read in the newspaper a summary of a research study suggesting that the consumption of a moderate amount of bittersweet chocolate reduces the risk of heart disease in older women.
You ask her who funded the research. Explain why such information is important. Intrigued by the idea of a research study on chocolate, you ob- tain a copy of the full report. Your mother is 51 years old, walks daily, and takes a weekly swim class. Her blood pressure is on the upper end of the normal range.
She does not smoke. Identify at least three aspects of the study that would cause you to doubt its relevance to your mother. Information about careers in dietetics is also available at this site. References 1. Carpenter, K. Mokdad, A. Marks, D. Stroup, and J. Actual causes of death in the United States, JAMA — Healthy People The Road Ahead. Institute of Medicine, Food and Nutrition Board. Add to Basket. Book Description Condition: new.
Seller Inventory think More information about this seller Contact this seller. Book Description Condition: New. Satisfaction Guaranteed! Book is in NEW condition. Seller Inventory Book Description soft cover. Condition: New. International Edition. No supplemental materials. International Editions may have a different cover or ISBN but generally have the exact same content as the US edition, just at a more affordable price. In some cases, end of chapter questions may vary slightly from the US edition.
International Editions are typically printed in grayscale, and likely will not have any color throughout the book.
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