Nutrition Class Notes PDF

Nutrition - ctrl+f Date: 01/05/2025 Timestamp= 3:45 Chapter 1 Functions of Nutrients Necessary for tissue formation, cell reparation, and hormone and enzyme production. It is essential for Protein...

Nutrition - ctrl+f Date: 01/05/2025 Timestamp= 3:45 Chapter 1 Functions of Nutrients Necessary for tissue formation, cell reparation, and hormone and enzyme production. It is essential for Protein building strong muscles and a healthy immune system. Provide a ready source of energy for the body and provide structural constituents for the formation of Carbohydrates cells. Provides stored energy for the body, functions as structural components of cells and also as signaling Fat molecules for proper cellular communication. It provides insulation to vital organs and works to maintain body temperature. Vitamins Regulate body processes and promote normal body-system functions. Minerals Regulate body processes, are necessary for proper cellular function, and comprise body tissue. Transports essential nutrients to all body parts, transports waste products for disposal, and aids with Water body temperature maintenance Nutrients ○ required by body to perform basic functions ○ must be obtained from diet ○ human body does not synthesize or produce them ○ have one or more of three basic functions i. provide energy ii. contribute to body structure iii. and/or regulate chemical processes in the body basic functions allow us to detect and respond to environmental surroundings, move, excrete wastes, respire (breathe), grow, and reproduce six classes of nutrients -carbohydrates, lipids, proteins, water, vitamins, and minerals. Foods also contain non-nutrients that may be harmful (such as natural toxins common in plant foods and additives like some dyes and preservatives) or beneficial (such as antioxidants). Macronutrients Nutrients that are needed in large amounts ○ 3 classes of macronutrients: carbohydrates lipids proteins ○ can be metabolically processed into cellular energy Energy comes from chem bonds. chemical energy is converted into cellular energy -> utilized to perform work, allowing bodies to conduct basic functions. Calorie- Unit of measurement of food energy ○ food labels amount given for “calories” equivalent to each calorie multiplied by 1000. ○ kilocalorie (one thousand calories, denoted with a small “c”) is synonymous with the “Calorie” (with a capital “C”) on food labels. Water is a macronutrient in the sense that you require a large amount, unlike other macronutrients, does not yield calories. Carbohydrates ★ molecules composed of carbon, hydrogen, oxygen ★ major food sources= grains, milk, fruits, starchy vegs ;Non-starchy vegs also contain, but in lesser quantities.  ★ classified in 2 forms based on chem structure=simple C.H. (simple sugars); & complex C.H ○ Simple cH consist of one or two basic units. Examples= Sucrose = sugar in breakfast bowl Glucose = sugar that circulates in blood. ○ Complex ch; long chains of simple sugars that can be unbranched or branched. During digestion, body breaks down digestible complex carbohydrates to simple sugars, mostly glucose. Glucose is then transported to all our cells where it is stored, used to make energy, or used to build macromolecules. Fiber also complex carbohydrate, cannot be broken down by digestive enzymes in human intestine. As a result, it passes through digestive tract undigested unless bacteria that inhabit colon or large intestine break it down. glucose can be stored in body for future use. 1. Humans, storage molecule of carbohydrates is glycogen 2. Plants, it is starch. 3. Glycogen & starch = complex carbohydrates. One gram digestible carbohydrates yields four kilocalories of energy for cells in body to perform work. Function = providing energy serving as building blocks for bigger macromolecules essential for proper functioning of the nervous system, heart, and kidneys. Glucose storage Lipids ○ molecules composed of carbon, hydrogen, and oxygen, unlike carbohydrates, are insoluble in water. ○ found predominantly in butter, oils, meats, dairy products, nuts, seeds, processed foods ○ ○ three main types triglycerides (triacylglycerols) Phospholipids Sterols ○ FUNCTION provide or store energy. *provide more energy per gram than carbohydrates (nine kilocalories per gram) major component of cell membranes surround and protect organs (in fat-storing tissues) provide insulation to aid in temperature regulation regulate many other functions in the body Proteins  macromolecules composed of chains of subunits called amino acids. Amino acids are simple subunits composed of carbon, oxygen, hydrogen, and nitrogen. Food sources of proteins include meats, dairy products, seafood, and a variety of different plant-based foods, most notably soy. The word protein comes from Greek word meaning “of primary importance,” , also known colloquially as the “workhorses” of life. four kilocalories of energy per gram providing energy is not most important function. ○ structure to bones ○ muscles and skin ○ a role in conducting most chem reactions in body. ○ Scientists estimate that greater than one-hundred thousand different proteins exist within the human body. ○ The genetic codes in DNA are basically protein recipes that determine the order in which 20 different amino acids are bound together to make thousands of specific proteins. Water not contain carbon, composed of 2 hydrogens; 1 oxygen per molecule of water More than 60% of total body weight Without it, ○ nothing could be transported in/out of body ○ chemical reactions would not occur ○ organs would not be cushioned ○ body temperature would fluctuate widely. On average, adult consumes just over 2L of water per day from food & drink combined amount of water input/output is important bc water is so critical for life’s basic processes Micronutrients - required by the body in lesser amounts, still essential for carrying out bodily functions. not sources of energy (calories) assist in process as cofactors or components of enzymes (i.e., coenzymes). ○ Enzymes = proteins that catalyze chem reactions in body involved in all aspects of body functions from producing energy, to digesting nutrients, to building macromolecules. include all essential minerals and vitamins - 16 essential minerals / 13 vitamins Minerals and Their Major Functions Macro Sodium Fluid balance, nerve transmission, muscle contraction Chloride Fluid balance, stomach acid production Potassium Fluid balance, nerve transmission, muscle contraction Calcium Bone and teeth health maintenance, nerve transmission, muscle contraction, blood clotting Phosphorus Bone and teeth health maintenance, acid-base balance Magnesium Protein production, nerve transmission, muscle contraction Sulfur Protein production Trace Iron Carries oxygen, assists in energy production Zinc Protein and DNA production, wound healing, growth, immune system function Iodine Thyroid hormone production, growth, metabolism Selenium Antioxidant Copper Coenzyme, iron metabolism  Manganese Coenzyme Fluoride Bone and teeth health maintenance, tooth decay prevention Chromium Assists insulin in glucose metabolism Molybdenum Coenzyme Minerals solid inorganic substances that form crystals classified depending on how much of them we need. Trace minerals are only required in a few milligrams or less. Macrominerals are required in hundreds of milligrams. Many minerals are critical for enzyme function others are used to ○ maintain fluid balance ○ build bone tissue ○ synthesize hormones ○ transmit nerve impulses ○ contract and relax muscles ○ protect against harmful free radicals in the body that can cause health problems such as cancer. Vitamins Major Functions Water-soluble Thiamin (B1) Coenzyme, energy metabolism assistance Riboflavin (B2 ) Coenzyme, energy metabolism assistance Niacin (B3) Coenzyme, energy metabolism assistance Pantothenic acid (B5) Coenzyme, energy metabolism assistance Pyridoxine (B6) Coenzyme, amino acid synthesis assistance Biotin (B7) Coenzyme, amino acid and fatty acid metabolism Folate (B9) Coenzyme, essential for growth Cobalamin (B12) Coenzyme, red blood cell synthesis C (ascorbic acid) Collagen synthesis, antioxidant Fat-soluble A Vision, reproduction, immune system function D Bone and teeth health maintenance, immune system function E Antioxidant, cell membrane protection K Bone and teeth health maintenance, blood clotting Vitamins categorized as either water-soluble or fat-soluble water-soluble = vitamin C and all B vitamins fat-soluble vitamins are A, D, E, and K. required to perform many functions in body such as ○ making red blood cells ○ synthesizing bone tissue ○ playing a role in normal vision ○ nervous system function ○ immune system function. Vitamin deficiencies can cause severe health problems and even death. ○ Example = deficiency in niacin causes disease called pellagra, common in early twentieth century in some parts of America. common signs and symptoms of pellagra are known as the “4D’s—diarrhea, dermatitis, dementia, and death.” Until scientists found out that better diets relieved the signs and symptoms of pellagra, many people with the disease ended up hospitalized in insane asylums awaiting death. Other vitamins were found to prevent certain disorders and diseases such as scurvy (vitamin C), night blindness (vitamin A), and rickets (vitamin D) Timestamp= 5:06 Food Quality One measurement of food quality is amount of nutrients it contains relative to amount of energy it provides. ○ Food quality is also associated w/ taste, texture, appearance, microbial content, how much consumers like it. High-quality foods are nutrient dense = contain significant amounts of 1/+ essential nutrients relative to amount of calories they provide. Nutrient-dense foods are opposite of “empty-calorie” foods Food: A Better Source of Nutrients (than supplements) better to get all your micronutrients from foods you eat as opposed from supplements ○ Supplements contain only what's listed on label ○ foods contain more macronutrients, micronutrients, and other chemicals, like antioxidants ○ vitamins, multivitamins, supplements are $20 billion industry in U.S, more than 50% Americans purchase/use daily ○ no consistent evidence they're better than food in promoting health/preventing disease. Units of Measure 2 systems of commonly used measurements: Metric & US Customary. We need both bc US won’t adopt metric system completely commonly used prefixes for the Metric System: Micro- (μ) 1/1,000,000th (one millionth) Milli- (m) 1/1000th (one thousandth) Centi- (c) 1/100th (one hundredth) Deci- (d) 1/10th (one tenth) Kilo- (k) 1000x (one thousand times)  Mass Metric System US Customary System Conversions Microgram (μg) Ounce (oz) 1 oz = 28.35 g Milligram (mg) Pound (lb) 1 lb = 16 oz Gram (g) 1 lb = 454 g Kilogram (kg) 1 kg = 2.2 lb Volume Metric System US Customary System Conversions Milliliter (mL) Teaspoon (tsp) 1 tsp = 5 mL Deciliter (dL) Tablespoon (tbsp) 1 tbsp = 3 tsp = 15 mL Liter (L) Fluid ounce (fl oz) 1 fl oz = 2 tbsp = 30 mL Cup (c) 1 c = 8 fl oz = 237 mL Pint (pt) 1 pt = 2 c = 16 fl oz Quart (qt) 1 qt = 4 c = 32 fl oz = 0.95 L Gallon (gal) = 4 qt 1 gal = 4 qt Length Metric System US Customary System Conversions  Millimeter (mm) Inch (in) 1 in = 25.4 mm Centimeter (cm) Foot (ft) 1 ft= 30.5 cm Meter (m) Yard (yd) 1 yd = 0.9 m Kilometer (km) Mile (mi) 1 mi = 1.6 km Lifestyles and Nutrition In addition to nutrition, health is affected by genetics, the environment, life cycle, and lifestyle. ○ One facet of lifestyle is dietary habits Dietary habits include what a person eats, how much a person eats during a meal, how frequently meals are consumed, and how often a person eats out. Other aspects of lifestyle include physical activity level, recreational drug use, sleeping patterns Physical Activity 2008, the Health and Human Services (HHS) released the Physical Activity Guidelines for Americans. HHS states “Being physically active is one of the most important steps that Americans of all ages can take to improve their health. The 2008 Physical Activity Guidelines for Americans provides science-based guidance to help Americans aged six and older improve their health through appropriate physical activity.” Guidelines recommend exercise programs for people in many different stages of their lifecycle. The HHS reports there's strong evidence that increased physical activity decreases risk of early death, heart disease, stroke, Type 2 diabetes, high blood pressure, and certain cancers; prevents weight gain and falls; and improves cognitive function in the elderly guidelines are scheduled for update in 2018. Also unveiled recently are the Canadian Physical Activity Guidelines, which are available at the website of The Canadian Society for Exercise Physiology Recreational Drug Use Smoking cigarettes can cause lung cancer, eleven other types of cancer, heart disease, and several other disorders or diseases that markedly decrease quality of life and increase mortality. In the United States, smoking causes more than four hundred thousand deaths every single year, which is far more than deaths associated with any other lifestyle component Centers for Disease Control and Prevention (CDC), excessive alcohol intake causes an estimated seventy-five thousand deaths per year  Staying away from excessive alcohol intake lowers blood pressure, the risk from injury, heart disease, stroke, liver problems, and some types of cancer. consuming alcohol in moderation has been found to promote health such as reducing the risk for heart disease and Type 2 diabetes in some people. (HHS) defines drinking in moderation as no more than one drink a day for women ;two drinks a day for men Illicit and prescription drug abuse are associated the increased risk of stroke, heart disease, cancer, lung disease, and liver disease Sleeping Patterns Sleeping can affect your health just as much as your diet. insufficient sleep increases the risk for heart disease, Type 2 diabetes, obesity, and depression. Abnormal breathing during sleep, a condition called sleep apnea, is also linked to an increased risk for chronic disease Personal Choice: The Challenge of Choosing Foods Different foods affect energy level, mood, how much is eaten, how long before you eat again, and if cravings are satisfied. Food regulates your appetite and how you feel. Some high fiber foods & high-protein foods decrease appetite by slowing digestive process and prolonging the feeling of being full or satiety. The effects of individual foods and nutrients on mood are not backed by consistent scientific evidence Most studies support that healthier diets are associated with a decrease in depression and improved well-being. Science has not been able to track the exact path in the brain that occurs in response to eating a particular food, but it is quite clear that foods, in general, stimulate emotional responses in people. Food has psychological, cultural, and religious significance The social implications of food have a great deal to do with what people eat, as well as how and when. ○ Special events in individual lives—from birthdays to funerals—are commemorated with equally special foods. Timestamp-540- no distractions or getting up since last one Factors that Drive Food Choices  Taste, texture, appearance. Individuals have a wide range of tastes which influence their food choices, leading some to dislike milk and others to hate raw vegetables. Some foods that are very healthy, such as tofu, may be unappealing at first to many people. However, creative cooks can adapt healthy foods to meet most people’s taste. Economics. Access to fresh fruits and vegetables may be scant, particularly for those who live in economically disadvantaged or remote areas, where cheaper food options are limited to convenience stores and fast food. Early food experiences. People who were not exposed to different foods as children, or who were forced to swallow every last bite of overcooked vegetables, may make limited food choices as adults. Habits. It’s common to establish eating routines, which can work both for and against optimal health. Habitually grabbing a fast food sandwich for breakfast can seem convenient, but might not offer substantial nutrition. Yet getting in the habit of drinking an ample amount of water each day can yield multiple benefits. Culture. The culture in which one grows up affects how one sees food in daily life and on special occasions. Geography. Where a person lives influences food choices. For instance, people who live in Midwestern US states have less access to seafood than those living along the coasts. Advertising. The media greatly influences food choice by persuading consumers to eat certain foods. Social factors. Any school lunchroom observer can testify to the impact of peer pressure on eating habits, and this influence lasts through adulthood. People make food choices based on how they see others and want others to see them. For example, individuals who are surrounded by others who consume fast food are more likely to do the same. Health concerns. Some people have significant food allergies, to peanuts for example, and need to avoid those foods. Others may have developed health issues which require them to follow a low salt diet. In addition, people who have never worried about their weight have a very different approach to eating than those who have long struggled with excess weight. Emotions. There is a wide range in how emotional issues affect eating habits. When faced with a great deal of stress, some people tend to overeat, while others find it hard to eat at all. Green food/Sustainability choices. Based on a growing understanding of diet as a public and personal issue, more and more people are starting to make food choices based on their environmental impact. Realizing that their food choices help shape the world, many individuals are opting for a vegetarian diet, or, if they do eat animal products, striving to find the most “cruelty-free” options possible. Purchasing local and organic food products and items grown through sustainable products also helps shrink the size of one’s dietary footprint. Four common forms of vegetarianism are: 1. Lacto-ovo vegetarian. This is the most common form. This type of vegetarian diet includes animal foods, eggs and dairy products. 2. Lacto-vegetarian. This type of vegetarian diet includes dairy products but not eggs. 3. Ovo-vegetarian. This type of vegetarian diet includes eggs but not dairy products. 4. Vegan. This type of vegetarian diet does not include dairy, eggs, or any type of animal product or animal by-product. Achieving a Healthy Diet five key factors that make up a healthful diet: 1. A diet must be adequate, by providing sufficient amounts of each essential nutrient, as well as fiber and adequate calories. 2. A balanced diet results when you do not consume one nutrient at the expense of another, but rather get appropriate amounts of all nutrients. 3. Calorie control is necessary so that the amount of energy you get from the nutrients you consume equals the amount of energy you expend during your day’s activities. 4. Moderation means not eating to the extremes, neither too much nor too little. 5. Variety refers to consuming different foods from within each of the food groups on a regular basis. A healthy diet is one that favors whole foods.. Whole foods supply the needed vitamins, minerals, protein, carbohydrates, fats, and fiber that are essential to good health. Commercially prepared and fast foods are often lacking nutrients and often contain inordinate amounts of sugar, salt, saturated and trans fats, all of which are associated with the development of diseases such as atherosclerosis, heart disease, stroke, cancer, obesity, diabetes, and other illnesses. A balanced diet is a mix of food from the different food groups (vegetables, legumes, fruits, grains, protein foods, and dairy). Restart time:741 Adequacy An adequate diet is one that favors nutrient-dense foods. Nutrient-dense foods are defined as foods that contain many essential nutrients per calorie. Nutrient-dense foods are the opposite of “empty-calorie” foods, such as sugary carbonated beverages, which are also called “nutrient-poor.” Nutrient-dense foods include fruits and vegetables, lean meats, poultry, fish, low-fat dairy products, and whole grains. Choosing more nutrient-dense foods will facilitate weight loss, while simultaneously providing all necessary nutrients. Balance Balance the foods in your diet. Achieving balance in your diet entails not consuming one nutrient at the expense of another. For example, calcium is essential for healthy teeth and bones, but too much calcium will interfere with iron absorption. ○ Most foods that are good sources of iron are poor sources of calcium, so in order to get the necessary amounts of calcium and iron from your diet, a proper balance between food choices is critical. Another example is that while sodium is an essential nutrient, excessive intake may contribute to congestive heart failure and chronic kidney disease in some people. Moderation Moderation is crucial for optimal health and survival. Eating nutrient-poor foods each night for dinner will lead to health complications. But as part of an otherwise healthful diet and consumed only on a weekly basis, this should not significantly impact overall health.  It’s important to remember that eating is, in part, about enjoyment and indulging with a spirit of moderation. This fits within a healthy diet. Monitor food portions. For optimum weight maintenance, it is important to ensure that energy consumed from foods meets the energy expenditures required for body functions and activity. If not, the excess energy contributes to gradual, steady accumulation of stored body fat and weight gain. In order to lose body fat, you need to ensure that more calories are burned than consumed. Likewise, in order to gain weight, calories must be eaten in excess of what is expended daily. Variety Variety involves eating different foods from all the food groups. Eating a varied diet helps to ensure that you consume and absorb adequate amounts of all essential nutrients required for health. One of the major drawbacks of a monotonous diet is the risk of consuming too much of some nutrients and not enough of others. Trying new foods can also be a source of pleasure—you never know what foods you might like until you try them. Research and the Scientific Method Nutritional scientists discover the health effects of food and its nutrients by first making an observation. Once observations are made, they come up with a hypothesis, test their hypothesis, and then interpret the results. After this, they gather additional evidence from multiple sources and finally come up with a conclusion. In 1811, French chemist Bernard Courtois was isolating saltpeter for producing gunpowder to be used by Napoleon’s army. To carry out this isolation, he burned some seaweed and in the process, observed an intense violet vapor that crystallized when he exposed it to a cold surface. He sent the violet crystals to an expert on gases, Joseph Gay-Lussac, who identified the crystal as a new element. It was named iodine, the Greek word for violet. The following scientific record is some of what took place in order to conclude that iodine is a nutrient  Observation. Eating seaweed is a cure for goiter, a gross enlargement of the thyroid gland in the neck. Hypothesis. In 1813, Swiss physician Jean-Francois Coindet hypothesized that the seaweed contained iodine, and that iodine could be used instead of seaweed to treat his patients Experimental test. Coindet administered iodine tincture orally to his patients with goiter. Interpret results. Coindet’s iodine treatment was successful. Hypothesis. French chemist Chatin proposed that the low iodine content in food and water in certain areas far away from the ocean was the primary cause of goiter, and renounced the theory that goiter was the result of poor hygiene. Experimental test. In the late 1860s the program, “The stamping-out of goiter,” started with people in several villages in France being given iodine tablets. Results. The program was effective and 80 percent of goitrous children were cured. Hypothesis. In 1918, Swiss doctor Bayard proposed iodizing salt as a good way to treat areas endemic with goiter. Experimental test. Iodized salt was transported by mules to a small village at the base of the Matterhorn where more than 75 percent of school children were goitrous. It was given to families to use for six months. Results. The iodized salt was beneficial in treating goiter in this remote population. Experimental test. Physician David Marine conducted the first experiment of treating goiter with iodized salt in America in Akron, Ohio. Results. This study was conducted on over four-thousand school children, and found that iodized salt prevented goiter. Conclusions. Seven other studies similar to Marine’s were conducted in Italy and Switzerland, which also demonstrated the effectiveness of iodized salt in treating goiter. In 1924, US public health officials initiated the program of iodizing salt and started eliminating the scourge of goiter. Today, more than 70% of American households use iodized salt and many other countries have followed the same public health strategy to reduce the health consequences of iodine deficiency. Evidence-Based Approach to Nutrition It took more than one hundred years from iodine’s discovery as an effective treatment for goiter until public health programs recognized it as such. Although a lengthy process, the scientific method is a productive way to define essential nutrients and determine their ability to promote health and prevent disease. The scientific method is part of the overall evidence-based approach to designing nutritional guidelines An evidence-based approach to nutrition includes ○ Defining the problem or uncertainty (e.g., the incidence of goiter is lower in people who consume seaweed)  ○ Formulating it as a question (e.g., Does eating seaweed decrease the risk of goiter?) ○ Setting criteria for quality evidence ○ Evaluating the body of evidence ○ Summarizing the body of evidence and making decisions ○ Specifying the strength of the supporting evidence required to make decisions ○ Disseminating the findings The Food and Nutrition Board of the Institute of Medicine, a nonprofit, non-governmental organization, constructs its nutrient recommendations (i.e., Dietary Reference Intakes, or DRI) using an evidence-based approach to nutrition. The entire procedure for setting the DRI is documented and made available to the public. The same approach is used by the USDA and HHS, which are departments of the US federal government. The USDA and HHS websites are great tools for discovering ways to optimize health; however, it is important to gather nutrition information from multiple resources, as there are often differences in opinion among various scientists and public health organizations. Types of Scientific Studies Type Description Example Notes Diets with a high Observational study of Does not consumption of saturated populations around the determine Epidemiological fat are associated with an world and the impact of cause-and-effect increased risk of heart nutrition on health. relationships. attacks. Testing the effect of different diets on blood pressure. One group Scientific investigations If done correctly, consumes an American Intervention where a variable is it does determine diet, group 2 eats a diet Clinical Trials changed between cause-and-effect rich in fruits and groups. relationships. vegetables, and group 3 eats a combination of groups 1 and 2.  Testing the effect of Participants are calcium supplements on assigned by chance to women with separate groups that osteoporosis. Participants Considered the compare different are given a pill daily of a Randomized “gold” standard treatments. Neither the placebo or calcium Clinical Trials for scientific researchers nor the supplement. Neither the studies. participants can choose participant nor the which group a researcher know what participant is assigned. group the participant is in. Less expensive Testing the effects of a than human Animal and Studies are conducted new blood pressure drug trials. Study is Cellular Biology on animals or on cells. on guinea pigs or on the not on whole lipid membrane of a cell. humans so it may be not applicable. Nutrition Assessment Nutritional assessment is the interpretation of anthropometric, biochemical (laboratory), clinical and dietary data to determine whether a person or groups of people are well nourished or malnourished (overnourished or undernourished). Nutritional assessment can be done using the ABCD methods. These refer to the following: A. Anthropometry B. Biochemical methods C. Clinical methods D. Dietary methods Anthropometry methods of assessing nutritional status The word anthropometry comes from two words: Anthropo means ‘human’ and metry means ‘measurement’. The different measurements taken to assess growth and body composition are presented below. To assess growth, several different measurements including length, height, weight, head circumference, mid-arm circumference, skin-fold thickness, head/chest ratio, and hip/waist ratio can be used. Height and weight measurements are essential in children to evaluate physical growth. As an additional resource, the NHANES Anthropometry Procedures Manual (revised January 2004) can be viewed here https://www.cdc.gov/nchs/data/nhanes/nhanes_03_04/BM.pdf Biochemical methods of assessing nutritional status Biochemical or laboratory methods of assessment include measuring a nutrient or its metabolite in the blood, feces, urine or other tissues that have a relationship with the nutrient. An example of this method would be to take blood samples to measure levels of glucose in the body. This method is useful for determining if an individual has diabetes. (blood glucose test) Clinical methods of assessing nutritional status In addition to the anthropometric assessments, you can also assess clinical signs and symptoms that might indicate potential specific nutrient deficiency. Special attention are given to organs such as skin, eyes, tongue, ears, mouth, hair, nails, and gums. Clinical methods of assessing nutritional status involve checking signs of deficiency at specific places on the body or asking the patient whether they have any symptoms that might suggest nutrient deficiency. Dietary methods of assessing nutritional status Dietary methods of assessment include looking at past or current intakes of nutrients from food by individuals or a group to determine their nutritional status. There are several methods used to do this:  ○ 24 hour recall - A trained professional asks the subject to recall all food and drink consumed in the previous 24 hours. This is a quick and easy method. However, it is dependent upon the subject’s short-term memory and may not be very accurate. ○ Food frequency questionnaire - The subject is given a list of foods and asked to indicate intake per day, per week, and per month. This method is inexpensive and easy to administer. It is more accurate than the 24 hour recall ○ Food Diary - Food intake is recorded by the subject at the time of eating. This method is reliable but difficult to maintain. Also known as a food journal or food record ○ Observed food consumption - This method requires food to be weighed and exactly calculated. It is very accurate but rarely used because it is time-consuming and expensive. Evolving Science Science is always moving forward, albeit sometimes slowly. One study is not enough to make a guideline or a recommendation, or cure a disease. Science is a stepwise process that builds on past evidence and finally culminates into a well-accepted conclusion. Unfortunately, not all scientific conclusions are developed in the interest of human health, and some can be biased. Therefore, it is important to know where a scientific study was conducted and who provided the funding, as this can have an impact on the scientific conclusions being made. For example, an air quality study paid for by a tobacco company diminishes its value in the minds of readers as well as a red meat study performed at a laboratory funded by a national beef association. Nutritional Science Evolution One of the newest areas in the realm of nutritional science is the scientific discipline of nutritional genetics, also called nutrigenomics. Genes are part of DNA and contain the genetic information that make up all of our traits. Genes are codes for proteins and when they are turned “on” or “off,” they change how the body works. While we know that health is defined as more than just the absence of disease, there are currently very few accurate genetic markers of good health. Rather, there are many more genetic markers for disease. However, science is evolving, and nutritional genetics aims to identify what nutrients to eat to “turn on” healthy genes and “turn off” genes that cause disease. Using Science and Technology to Change the Future As science evolves, so does technology. Both can be used to create a healthy diet, optimize health, and prevent disease. Using Eyes of Discernment 1. The scientific study under discussion should be published in a peer reviewed journal, such as the Journal of Nutrition. Question studies that come from less trustworthy sources (such as non peer-reviewed journals or websites) or that are not formally published. 2. The report should disclose the methods used by the researcher(s). Did the study last for three or thirty weeks? Were there ten or one hundred participants? What did the participants actually do? Did the researcher(s) observe the results themselves or did they rely on self reports from program participants? 3. Who were the subjects of this study? Humans or animals? If human, are any traits/characteristics noted? You may realize you have more in common with certain program participants and can use that as a basis to gauge if the study applies to you. 4. Credible reports often disseminate new findings in the context of previous research. A single study on its own gives you very limited information, but if a body of literature supports a finding, it adds to credibility. 5. Peer-reviewed articles deliver a broad perspective and are inclusive of findings of many studies on the exact same subject. 6. When reading such news, ask yourself, “Is this making sense?” Even if coffee does adversely affect the nervous system, do you drink enough of it to see any negative effects? Remember, if a headline professes a new remedy for a nutrition-related topic, it may well be a research-supported piece of news, but more often than not, it is a sensational story designed to catch the attention of an unsuspecting consumer. Track down the original journal article to see if it really supports the conclusions being drawn in the news report. When reading information on websites, remember the following criteria for discerning if the site is valid: 1. Who sponsors the website? 2. Are names and credentials disclosed? 3. Is an editorial board identified? 4. Does the site contain links to other credible informational websites? 5. Even better, does it reference peer-reviewed journal articles? If so, do those journal articles actually back up the claims being made on the website? 6. How often is the website updated? 7. Are you being sold something at this website? 8. Does the website charge a fee? Organizations Active in Nutrition Policy and Research Authoritative nutritional news will be based upon solid scientific evidence, supported by multiple studies, and published in peer-reviewed journals. Whatever the source of your nutritional news, remember to apply the criteria outlined above to help ensure the validity of the information presented. Below are some examples of websites which can be considered credible sources for nutritional news.  US Department of Agriculture Food and Nutrition Information Center. The USDA site http://fnic.nal.usda.gov has more than 2,500 links to information about diet, nutrition, diet and disease, weight and obesity, food-safety and food-labeling, packaging, dietary supplements and consumer questions. Using this interactive site, you can find tips and resources on how to eat a healthy diet, nutritional information, and a food planner. The Academy of Nutrition and Dietetics (AND). The AND promotes scientific, evidenced-based, research-supported food and nutrition related information on its website, http://www.eatright.org. It is focused on informing the public about recent scientific discoveries and studies, weight-loss concerns, food safety topics, nutrition issues, and disease prevention. Department of Health and Human Services (HHS). The HHS website, HealthFinder.gov, provides credible information about healthful lifestyles and the latest in health news. A variety of online tools are available to assist with food-planning, weight maintenance, physical activity, and dietary goals. You can also find healthful tips for all age groups, tips for preventing disease, and information on daily health issues in general. Centers for Disease Control and Prevention (CDC). The Centers for Disease Control and Prevention (http://www.cdc.gov) distributes an online newsletter called CDC Vital Signs which provides up-to-date public health information and data regarding food, nutrition, cholesterol, high blood pressure, obesity, teenage drinking, and tobacco usage. End of ch1- timestamp 8:17 - mp distractions or breaks