BCS 132-106 January 15, 2013
READING GUIDE CHAPTER 1: What is Nutrition
1. Identify and discuss factors that affect food choices. (Course objective 1) 2. Define: nutrition, nutrients, essential nutrients, non essential nutrients, kilocalorie 3. Identify the six classes of nutrients utilized by humans and describe their basic functions in the body. (Course Objective 4) 4. Describe the steps of the scientific method.
5. Describe the following components of research studies: experimental group, control group, placebo, double-blind placebo-controlled study 6. Discuss the types of research studies and methods used to acquire valid nutrition information. (Course objective 2) 7. Differentiate between reputable and non-reputable sources of nutrition information. 8. Differentiate between the various methods used to assess the nutrient status of individuals and population groups. Discuss the "pros" and "cons
TEACH YOURSELF THE BASICS:
What Drives Our Food Choices?
1. Identify at least five factors that influence our food choices. Taste,enjoyment, culture, environment, social reasons, and popular trends. 2. Discuss examples of at least three of the factors identified in question 1. Taste is considered the number one factor when it comes to choosing foods. Foods that are salty and sweet are among the top choices. Culture plays an important role in choosing food. Foods that are easily available to a group of the population are more likely to be eaten over foods that are rare to the location. Someone from China may have different choices than someone from Italy. Social trends also have a role to play in choosing food. What family and friends eat and foods considered popular may be chosen over other foods, despite health concerns. **Make sure to read “The Take-Home Message” for this section (Pg. 7)
What is Nutrition?
1. Explain how the focus of the study of nutrition has changed over time. Nutrition began a few hundred years ago as a science relating nutrients to diseases and its affects, but today is used as a way to promote good health and long life by healthy eating. ** Make sure to read “The Take-Home Message” for this section (Pg. 9)
What are Nutrients?
1. List the six categories of nutrients found in foods and in the body. Carbohydrates, Lipids (fats), Proteins, Vitamins, Minerals, and Water 2. Which nutrients provide energy?
Carbohydrates, lipids, and proteins. Alcohol also provides energy but is not considered a nutrient. 3. When we use the term “calorie” to describe the energy content of food, are we actually referring to the word “calorie” or are we referring to the word “kilocalorie”? Explain. Kilocalorie, not calorie, is the correct term when referring to the energy content of food. Calorie is a much smaller unit of measurement. 4. How many kilocalories are provided in a gram of carbohydrate? Protein? Fats? Carbohydrates and Proteins have 4 kilocalories and Lipids or fats have 9 kilocalories. **Make sure to read “The Take-Home Message” for this section (Pg. 13)
What Are the Primary Roles of the Individual Nutrients?
1. For each of the 6 classes of nutrients, briefly describe their primary role in the body. Use the table below to guide you. Macronutrients include carbohydrates, proteins, fats and water. Carbohydrates are the body’s Mai’s source of energy. Proteins provide the building blocks, or amino acids, for tissue in the body. Fats are also a source of energy but in a more concentrated form. Water makes up a majority of the fluids in the body, as well as its tissues. Micronutrients include vitamins and minerals. Vitamins help regulate metabolism and use other nutrients, while minerals assist in body processes.
2. List some food sources for carbohydrates, lipids and proteins. Carbohydrates include bread, cereals and nuts. Lipids include butter and oils. Proteins include meat and dairy. 3. Classify the vitamins according to whether they are water soluble or fat soluble. Water soluble vitamins include vitamin C and the 8 B-complex vitamins. Fat soluble vitamins include A, D, E, and vitamin K. 4. Give examples of major minerals and trace minerals.
Major minerals include calcium and magnesium, while Trace minerals include iron and zinc. **Make sure to read “The Take-Home Message” for this section (Pg. 16)
What is Credible Nutrition Research?
1. What are some questions you can ask yourself to evaluate the credibility of published nutrition information (in print or on the internet)? Was the research findings published in a peer-reviewed journal? Was the study done on animals or humans? Is this the first time I have heard this? Do the study participants resemble me? 2. Describe the steps of the scientific method.
Scientists observe the natural world, ask questions, and put forth or submit an explanation, called a hypothesis, bases on what they observed. Next they test this hypothesis to determine if it is correct or not. After testing or conducting an experiment, it can be determined if the hypothesis is supported or not by the findings. If supported, the findings can be published. If not supported, the scientist then must revise or redo the hypothesis.
3. Why is a double-blind placebo-controlled study considered the “gold standard” of research? This study is the gold standard because all variables are the same and controlled for the groups with no bias toward any group or researcher. 4. How does sample size affect the credibility of research results? The sample sizes must be large enough so that any differences in the study are related to treatment and not just chance. **Make sure to read “The Take-Home Message” for this section (Pg. 21)
What Is Nutrition Assessment and What Does It Involve?
1. Briefly describe the different methods for assessing the nutrition status of individuals. Which one is the “best” method? Explain your reasoning. Anthropometric data is used to determine body size or composition. Data gathered is compared to reference standards, which can help determine risk factors for developing disease. Biochemical tests assess nutrient levels in body fluids, how fast nutrients are excreted through urine, and metabolic by products of nutrients found in urine. Clinical tests inspect the body for over or under nutrition by inspecting hair, nails and lips. Dietary intake can be measured by interviews and questionnaires to reveal lifestyle habits. The most important of the four would be anthropometric due to its ability to evaluate for disease such as diabetes.
**Make sure to read “The Take-Home Message” for this section (Pg. 27)
How Do We Assess the Nutritional Status of a Population Group? 1. How are nutritional assessment methods for a population group different than those which would be used for an individual? For a large population national surveys are used to determine nutritional status.
How Does the American Diet Stack Up?
1. Summarize how the American diet compares to dietary recommendations. Americans eat too much protein, sugar, sodium, saturated fat and not enough fiber, some vitamins and minerals. **Make sure to read “The Take-Home Message” for this section (Pg. 30) What’s the Best Dietary Strategy for Health?
1. Is the following statement true or false: A variety of whole foods will meet everyone’s nutritional needs and there should be no need for nutritional supplements. Explain your answer. False. Some individuals have diet restrictions or higher nutrient needs such as a pregnant woman or someone who is lactose intolerant. **Make sure to read “The Take-Home Message” for this section (Pg. 31)
Nutrition: The science that studies how nutrients and compounds in foods nourish the body and affect body functions and overall health. Nutrients: Compounds in foods that sustain body processes. There are six classes of nutrients: carbohydrates, fats, proteins, vitamins, minerals, and water Essential Nutrients: Nutrients that must be consumed from foods because they cannot be made in the body in sufficient quantities to meet its needs and support health. Nonessential Nutrients: Nutrients that can be made in sufficient quantities in the body to meet the body’s requirements and support health. Energy Yielding Nutrients: The three nutrients that provide energy to the body to fuel physiological functions: carbohydrates, lipids, and protein. Kilocalorie: The amount of energy required to raise the temperature of 1 kilogram of water 1 degree centigrade; used to express the measurement of energy in foods; 1 kilocalorie is equal to 1000 calories. Macronutrients: Organic nutrients, including the energy-containing carbohydrates, lipids, proteins, and water that the body needs in large amounts. Micronutrient: Essential nutrients the body needs in smaller amounts: vitamins and minerals. Water Soluble Vitamins: Vitamins that dissolve in water: Generally cannot be stored in the body and must be consumed. Fat Soluble Vitamins: Vitamins that dissolve in fat and can be stored in the body. Major Minerals: Minerals needed by the body in amounts greater than 5 grams; Aka Macro minerals. Trace Minerals: Minerals needed by the body in amounts less than 5 grams; Aka Micro minerals. Peer Reviewed Journal: A journal in which scientists publish research findings, after the findings have gone through a rigorous review process by other scientists. Observational Research: Research that involves systematically observing subjects to see if there is a relationship to certain outcomes. Experimental Group: In experimental research, the group of participants are given a specific treatment, such as a drug, as part of the study. Control Group: in experimental research, the group that does not receive the treatment but may be given a placebo instead; used as a standard for comparison. Placebo: An inactive substance, such as a sugar pill, administered to a control group during an experiment. Double-Blind Placebo-Controlled Study: An experimental study in which neither the researchers nor the subjects in the study are aware who is receiving the treatment or the placebo. Nutritional Genomics: A field of study of the relationship between genes, gene expression, and nutrition. Registered Dietician: A health professional who is a food and nutrition expert; RDs obtain a college degree in nutrition from an American Dietetic Association (ADA) accredited program, and pass an exam to become a Registered Dietician. Malnourished: A condition that results when the body does not receive the right amount of essential nutrients to maintain health; over nourished and undernourished are forms of malnutrition. Malabsorption: A problem associated with the lack of absorption of nutrients through the intestinal tract. Medical Nutrition Therapy: The integration of nutrition counseling and dietary changes based on individual medical and health needs, to treat a patient’s medical condition. Quackery: The promotion and selling of health products and services of questionable validity. Body Mass Index (BMI): A measurement calculated as height divided by weight squared; used to determine whether an individual is underweight, at a healthy weight, or overweight. Overweight: For adults, having a BMI greater than 25.
Obesity: For adults, having a BMI greater than 30.
Here are a few examples of reliable nutrition and health websites.
• American Dietetic Association: www.eatright.org
• Centers for Disease Control: www.cdc.gov
• Food and Drug Administration: www.fda.gov
• National Institutes of Health: www.nih.gov
• U.S. Department of Agriculture: www.nutrition.gov
• American Cancer Society: www.cancer.org
For additional resources, animations, and news stories over topics from this chapter, click on “Chapter Contents” on your Blackboard page, then click on “Chapter 1.”