Nutrition Exam 1 (Chapters. 1-3)

What are villi and microvilli?

(villi) the internal circular folds of the small intestine carry fingerlike projections called villi that increase its surface area for absorption. (microvilli) These villi are densely covered with fine hairlike projections called microvilli that further increase surface area and the efficiency of absorption.

Describe mechanisms by which food is propelled through the GI tract.

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How much energy is provided by Water?

0

Describe 3 types of experimental design (nutrition studies) and the primary advantages of each.

1) Randomized Controlled Trial-Results are directly applicable to humans 2)Epidemiological Studies-Can assess complex interactions among genetic , behavioral, and environmental factors. 3)Experimental Model Systems-Can be performed when human studies would be too costly, would be unethical, or would require an impractical length of time to complete.

How much energy is provided by Carbohydrates?

4 kcal/g

How much energy is provided by Proteins?

4 kcal/g

How much energy is provided by Lipids?

9 kcal/g

Define nutrients

A chemical substance that is required for growth and maintains proper body functioning.

What is a registered dietitian nutritionist? (RDN)

A food and nutrition expert who has met the minimum academic and professional requirements to qualify for the credential.

What does it mean to have a healthy gut microbiota?

A healthy gut microbiota contains a diverse and well-balanced array of hundreds of different types of bacteria that have an intricate and interactive relationship with each other and their human host.

Given that Alcohol supplies energy, Why is it not considered a nutrient?

Alcohol provides 7 kcal/g of energy but it is not considered as a nutrient because it is a toxin and does not support growth, maintenance, or repairs the body.

What are the components of a healthy diet?

All types of healthy diets have a few qualities in common: a variety of foods, balance across food groups and macronutrients (carbohydrates, protein, and fats), and adequate amounts that provide the calories and essential nutrients necessary to maintain and promote optimal health. Another key component to remember is moderation—not overindulging in any one type of food or in potentially harmful foods, such as those that contain excess amounts of sugar, salt, and unhealthy fat. A healthy diet is balance: the right proportion of foods from each of the food groups and the appropriate amounts of calories, macronutrients, vitamins, and minerals.

What types of mechanical and chemical digestion happen in each part of the digestive system?

Both mechanical and chemical digestion occur in the mouth. Teeth grind and break up food (mechanical), while an enzyme in saliva called amylase begins to break down carbohydrates (chemical). After it is swallowed, the chewed food (now called a bolus) moves down the esophagus.

Out of the six classes of nutrients, which are macronutrients?

Carbohydrates, Proteins, Lipids (fats), and Water.

Understand the body's organization, from cells to organ systems.

Cells (smallest functional unit of living organisms) to tissues, tissues (collection or cells, lining of small intestine) to organs, organs (assembly of cells different tissue types, 3 types connective, muscles and nervous) to Organ System (Are group of organs that work together for one or more functions).

What are phytochemicals?

Chemicals in plants that are beneficial to human health. It gives the plants key properties such as color, flavor and aroma.

Describe the evolution of US Food Guides and MyPlate

During the 1940s, for instance, the government promoted the "Basic 7," in which people were encouraged to eat something from each of seven categories of foods (for example, meat, milk, and green/yellow vegetables) The Basic 7 eventually became the "Basic 4" in the 1960s and 1970s, which painted a simpler picture of a nutritious diet but lacked specific guidance about fats, sugar, and calories. In the 1990s, a new Food Guide Pyramid ranked the five food groups by how much of each to consume per day. The iconic pyramid illustrated graphically the key concepts of variety, moderation, and proportion. After 20 years of promoting variations on the Food Guide Pyramid, in 2011, the USDA released MyPlate—a new tool to help consumers make better food choices.

Nutrient Intake Recommendations

Estimated Average Requirement (EAR) Recommended Dietary Allowance (RDA) Adequate Intake (AI) Tolerable Upper Intake Level (UL)

Understand the structure and function of the stomach.

Food with more fiber, for instance, slows emptying from the stomach, helping you feel full, or satiated. But as fiber passes into the large intestine, it can also stimulate propulsive contractions, which speeds up the transit of the intestinal contents through the rest of the digestive system, which helps promote regular bowel movements. These combined effects of fiber are important and help explain why nutrition professionals recommend healthy amounts of vegetables, fruits, whole grains, and other high-fiber foods in the diet.

What are some common nutrition-related digestive disorders?What are some potential nutritional/dietary implications and interventions for these disorders?

Gastroesophageal reflux disease-is a recurrent and more serious form of acid reflux that is accompanied by inflammation and/or erosion of the esophageal lining along with pain and gastrointestinal issues. Intervention: Fortunately, over-the-counter and prescription drugs can treat GERD, and sufferers can control symptoms by avoiding foods that cause discomfort, including alcohol, onions, chocolate, citrus fruits, and large or fatty meals. Diverticular Disease: is a common condition characterized by pouches or pockets in the wall or lining of any portion of the digestive tract, which can develop when the inner layer of the digestive tract pushes through weak spots in the outer layer. Intervention:A diet rich in fiber along with an active lifestyle appear to have a significant protective effect. Acid Reflux-is a condition in which the sphincter muscles separating the stomach and the esophagus relax, so food and stomach acid are occasionally regurgitated back into the esophagus. The stomach acid can cause a burning feeling called heartburn. Gallstones-can develop when substances in bile crystallize into small pebbles within the gallbladder. Intervention: With gallstones, the gallbladder may not be able to empty properly, causing pain in the upper abdomen. Recurrent gallstones generally require the surgical removal of the gallbladder. Hemorrhoids/Constipation-having a bowel movement fewer than three times per week is another symptom common in digestive disorders. Intervention: a low-fiber diet, certain medications, lack of physical activity, or dehydration may be contributors. Consuming sufficient fiber along with adequate fluid intake softens stools because it holds water, thus decreasing the risk of both constipation and painfully inflamed veins in the lower rectum or anus, a condition called hemorrhoids. Vomiting-the forceful movement of stomach contents from the stomach through the mouth and out of the body—can be caused by many things, including emotional stress, motion sickness, viruses, or foodborne bacteria. Diarrhea-which is defined as frequent loose and watery bowel movements that occur more than three times a day.

Describe some examples of small shifts in eating habits that may contribute to healthy eating patterns.

Increase Fruit intake especially whole fruits Juice box/Fruit bar for fresh strawberries or an apple. Variety or veggies, Chips for peppers Consume half of all grains as whole grains White or regular noodles to whole grain Replace butter for oils replace solid fats with oils where possible. Soda and candy for water and nuts get rid of those added sugars.

What is the difference between mechanical and chemical digestion?

Mechanical digestion is the physical fragmentation of foods into small particles, whereas chemical digestion breaks chemical bonds to cleave large molecules into smaller ones. Mechanical digestion begins in the mouth, where teeth crush and tear food into small bits. mechanical digestion is all that is required to release many vitamins, minerals, and phytochemicals from foods that are then taken up by mucosal cells lining the small intestine.

How might minimally processed foods contribute to a healthy diet?

Minimally processed foods can be just as nutritious as their unprocessed counterpart, such as bagged spinach, frozen vegetables, canned tuna, or roasted nuts.

What is NHANES?

National Health and Nutrition Examination Survey is a program that collects data for individuals about their food and nutrient consumption and conducts physical examinations.

Are all processed foods created equal?

No they are not. Processed foods encompass a wide range of food products, some of which can actually contribute favorably to nutrient intake and overall dietary quality. Minimally processed foods can be just as nutritious as their unprocessed counterpart, such as bagged spinach, frozen vegetables, canned tuna, or roasted nuts.

What's on the Food Label?

On every food label, you will see serving size, number of servings, and number of calories per serving, as well as information on the amount of dietary fat, cholesterol, dietary fiber, dietary sodium, carbohydrates, proteins, and four other vitamins and minerals (in addition to sodium) in each serving.

What are the links between food deserts and health?

People around the world were more likely to be obese and die prematurely from diet-related chronic disease such as diabetes, heart disease, and cancer. The same pattern of disease was evident even when Gallagher used statistical tools to remove the influence of race, income, education, and other factors that could affect health—independent of access to nutritious foods. The residents of food deserts were finding it next to impossible to eat nutrient-dense diets.

Understand the difference between peristalsis and segmentation Understand the path of digestion from the mouth to the large intestine

Peristalsis creates propulsive muscle contractions to move food forward through the complete length of the GI tract, from the esophagus to the anus. Segmentation, in contrast, occurs when circular muscles in the small intestine contract in an uncoordinated fashion so that fluid contents gently slosh back and forth between the segments These contractions serve to mix intestinal contents with digestive fluids and bring nutrients in the intestinal fluid in contact with the small intestine's absorptive surface. Similar segmentation contractions also occur in the large intestine.

What happens as food passes from the esophagus to the stomach?

Peristalsis squeezes your esophageal muscles from top to bottom. This pushes food and liquid along. If you could see peristalsis, it would look like a wave passing down your esophagus. To keep food and liquids moving in the right direction, your digestive tract has special muscles along its course called sphincters.

Pancreas

Produces enzymes to digest energy providing nutrients and releases bicarbonate to naturalize stomach acid.

What is the difference between RDA, AI, EAR, and UL?

RDA Average amount of a nutrient that meets the needs of nearly all (97 to 98 percent) individuals. Based on the EAR, but set higher. AI is the best estimate of the amount of a nutrient needed for good health. Used when there is insufficient data to determine the EAR or RDA EAR is the average amount of a nutrient known to meet the needs of 50 percent of individuals in the same age and gender group. The starting point for determining the amount needed for good health UL is the maximum amount of nutrient allowed that has been proven to have no risk of side effects.

What are the DRI values?

Reference values for vitamins, minerals, macronutrients and energy tat are used to assess and plan the diets of healthy people of the US and Canada.

Which enzymes play a role in digestion in the mouth?

Saliva contains special enzymes that help digest the starches in your food. An enzyme called amylase breaks down starches (complex carbohydrates) into sugars, which your body can more easily absorb. Saliva also contains an enzyme called lingual lipase, which breaks down fats.

Where can you find credible sources of nutrition information?

Scientific Peer review journals, RD, Government Publications (Nutrition, Diet and Health Reports) Nonprofit, Professional Health Organizations, Scientific Organizations.

How do secretions from accessory organs aid in digestion in the small intestine?

Secretions from accessory organs such as the pancreas and gallbladder play an important role in the digestion of the hamburger in the lumen of the small intestine. Chyme that enters the small intestine from the stomach is very acidic, and if it doesn't get neutralized, it denatures and inactivates the enzymes required for digestion. The pancreas releases pancreatic juice that contains bicarbonate akin to baking soda that neutralizes the gastric acids in chyme. The liver and the gallbladder also help to digest the many lipids found in the hamburger. The liver produces bile—which is stored in the gallbladder, a small, pear-shaped sac below the liver in the right upper abdomen—that contains substances critical for effective lipid digestion.

What is the function of the lower esophageal sphincter?

That normally functions as a one-way valve (as do other sphincters in the body). As food nears the lower-esophageal sphincter, that sphincter relaxes to let food pass into the stomach; otherwise, the sphincter stays tightly closed to prevent foods and secretions in the stomach from moving backward into the esophagus.

What is the role of bacteria in the gastrointestinal tract?

The bacteria that inhabit our GI tract are the dominant component of our gut microbiota—the complex community of all microorganisms (such as bacteria and even fungi) that live there.

What is the function of gastric juices?

The bolus then enters the stomach, a muscular, J-shaped sack that can accommodate up to 4 cups of food and generally takes about two to four hours to empty. The stomach secretes gastric juices that contain hydrochloric acid (HCL), which help to unfold the proteins in the food through chemical digestion. The gastric juices also contain enzymes such as proteases that digest proteins and lipase that digests fat. Importantly, the gastric juices also contain mucus that lubricates the food and protects the stomach lining from acidity.

Describe the circulation of nutrients in blood and lymph through the circulatory system.

The circulatory system, which includes both blood vessels and the lymphatic system, distributes vital nutrients to tissues and organs. Some nutrients as well as many of the toxins we ingest are largely removed from the blood by the liver, where they are then metabolized. Metabolism includes all of the chemical reactions that occur within the human body that convert one molecule into another molecule to provide energy or to synthesize substances that are required to sustain life.

What are the Dietary Guidelines for Americans?

The current dietary guidelines also focus on improving the diet of Americans by encouraging small shifts in eating habits to align our diet with these healthy eating patterns.

Identify and describe the function of the organs and accessory organs of the GI tract.

The digestive system includes the organs of the GI tract and accessory organs: the salivary glands, liver, gallbladder, and pancreas, all of which secrete fluids containing a variety of agents, such as enzymes and acids, that aid in digestion. The gastrointestinal tract (mouth, esophagus, stomach, small intestine, and large intestine) is responsible for the processes of ingestion, digestion, absorption, and excretion. Accessory organs that support digestion include the salivary glands, liver, gallbladder, and pancreas.

What are the absorptive and secretory functions of the large intestine?

The large intestine has 3 primary functions: absorbing water and electrolytes, producing and absorbing vitamins, and forming and propelling feces toward the rectum for elimination

What is the primary role of the large intestine?

The purpose of the large intestine is to absorb water and salts from the material that has not been digested as food, and get rid of any waste products left over.

Describe credible sources of nutrition information.

The quality of individual studies, the number of studies and the consistency of their results, and the magnitude of the effect. Experts have had extensive training including clinical/research experience that equip them to evaluate and translate info into dietary and health advice.

Understand/Explain the basis of the Scientific Method and how it is used in nutrition research.

The scientific method is a specific series of steps that involves a hypothesis, measurements and data, and interpretation of results. 1) Observations (The first step) 2) Question (Next we ask questions about the observations we made) 3) Hypothesis (Testable, which is a proposed explanation for an observation that can be tested through an experiment.) 4) Experiment (Develop an experiment to test the hypothesis) 5) Results/Conclusion 6)Present/share results. Nutrition Research is to help us explore and evaluate the role of diet and dietary components in health and diseases by animal experimentation

What are the three sections of the small intestine?

The small intestine has three sections: the duodenum, the first portion of the small intestine after the stomach; the jejunum, the middle portion; and the ileum, the last and longest portion. The small intestine isn't actually "small" at all; it is a coiled hollow tube approximately 20 feet long and 1 1/2 inches wide

How do the structural features of the small intestine facilitate absorption of nutrients?

The small intestine is the primary site for the digestion of food and the absorption of nutrients, and as we shall see, it is where digestion can go awry in people with celiac disease.

What are taste buds?

The tongue contains taste buds that identify or sense foods on the basis of specific flavors or tastes. Food is a combination of five primary tastes: sweet, sour, salty, bitter, and umami, a more recently recognized savory flavor that's harder to identify but may be an element of your burger, as it's found in meats, seafood, cheese, and some vegetables. The number of taste buds we have declines with age, which explains why children—whose tongues have abundant taste-sensing cells

Explain the four main functions of the digestive tract.

There are four basic stages to the digestive process: First, food is ingested through the mouth and enters the tubular channel called the alimentary canal, also called the gastrointestinal tract (GI tract). The GI tract extends from the mouth to the anus and includes the mouth, esophagus, stomach, small intestine, and large intestine. Second, as food passes through the GI tract, it is digested, or broken down into smaller units. Third, these smaller units of nutrients then undergo absorption, meaning that they pass into the bloodstream or lymphatic system, which transports them throughout the body. Finally, anything not absorbed is excreted as waste through the opening (the anus) at the other end.

Differentiate between nutrient-dense and energy-dense foods

These foods contain high nutrient levels relative to calorie content. Nutrient-dense foods are a "good deal" nutritionally in that they provide many nutrients at a relatively lower calorie "cost." Healthy diets also take into consideration the energy density of foods. Foods that have a high-calorie content relative to weight are considered energy-dense. Nutrient-rich nuts fit this description, but many foods that are dense in calories tend to be low in nutrients, such as cookies and chips.

How much energy is provided by Minerals/Vitamins?

They are a micronutrient they don't provide energy but they are essential for a healthy diet to maintain good health.

Describe the processed foods continuum

Those that are minimally processed to ultra-processed, convenience and ready to eat meals that require little or no preparation.

What transport mechanisms are involved in nutrient absorption?

To enter the mucosal cells lining the GI tract, water and small amounts of a few other nutrients can pass directly through the cell membrane by simple diffusion. The cell membrane serves as the boundary that holds the content of the body's cells in place and keeps their internal structures safe so that cells function properly. The membrane also serves as a semipermeable filter through which nutrients can enter and wastes can be excreted. Many nutrients enter the cells by facilitated diffusion, which requires a specific transport protein to help each of these nutrients move through the cell membrane. Simple diffusion and facilitated diffusion depend on the cell's concentration gradient, which moves molecules across the cell membrane from an area of high concentration to an area of low concentration. The entry of other nutrients into cells depends on active transport, which requires both a transport protein and energy to bring them across a membrane.

What are some visual cues for estimating portion sizes?

Visual Cues are you can use a golf ball = 1/4 cup 2 ounces, Baseball = 1 cup, Thumb = 1 tbsp or 1/2 oz.

Out of the six classes of nutrients, which are micronutrients?

Vitamins and Minerals

What happens when undigested nutrients in chyme pass into the large intestine?

When all of the nutrients have been absorbed from chyme, the remaining waste material passes to the end of the large intestine, the sigmoid colon and rectum, to be stored as fecal matter until it is ready to be excreted from the body.

Explain the importance of enzymes and hormones in digestion

Without the work of enzymes, digestion (and many other body processes) could not occur. An enzyme is a protein molecule that functions to catalyze, or speed up, the rate at which a chemical reaction produces new compounds with altered chemical structures. These reactions may subtly alter the chemical structure, or they may produce dramatically larger or smaller molecules. Enzymes have a specific shape that will fit only molecules that have a coordinating shape, like matching pieces of a puzzle. As facilitators, the enzymes bind to their coordinating molecule, initiate a chemical reaction, and move on. Thus, enzymes can participate in these chemical reactions many times without being altered themselves. The salivary glands, stomach, pancreas, and small intestine produce enzymes to break down the chemical compounds in food into units that are small enough to be absorbed.

Define malnutrition

a state of inadequate or unbalanced nutrition.

What are AMDR and EER?

adequate macronutrient distribution ranges (AMDRs): a range of intake as a percentage of energy, that promotes good health: provide input for carbs, proteins, fats, and essential fatty acids estimated energy requirement (EER): The estimated number of calories per day required to maintain energy equilibrium in a healthy adult: This value is dependent on sex, age, height, weight, and level of physical activity.

How does food composition affect energy density?

as the energy density of foods increases, the nutrient density decreases.

What are healthy people goals?

attain high-quality, longer lives free of preventable disease, disability, injury, and premature death; achieve health equity, eliminate disparities, and improve the health of all groups; create social and physical environments that promote good health for all.

What are the six classes of nutrients?

carbohydrates, lipids, proteins, vitamins, minerals, water

What factors determine how quickly the stomach empties into the small intestine?

depends on the composition and quantity of the foods and fluids you consume. Example: A hamburger typically spends 24-72 hours going from the mouth to the anus, but this transit time can change because of illness, medication, your level of activity, and even your emotional state.

What is chyme?

grinds the food into a semiliquid mass called chyme. A few teaspoons at a time, chyme is passed along to the small intestine, moving through the partially relaxed pyloric sphincter that functions as a sieve, allowing only small food particles (generally smaller than 1 millimeter, or about the size of the tip of a sharpened pencil) to pass through.

Identify the information that is required on food labels, and describe how this information can be used to select healthier foods

key information that consumers need to make informed decisions about the foods they eat.

What is a food desert?

large, mostly poor areas with little or no access to full-service grocery stores that sell a variety of healthy foods, including low-fat dairy, lean protein sources, whole grains, and produce.

Define essential nutrients

nutrients that must be supplied through food because the body itself cannot produce/synthesize sufficient quantities to meet its needs

What is the difference between prebiotics and probiotics, and what are food sources of each?

probiotics— Live Microorganism ,which when consumed ub adequate amounts provide health benefits. help maintain or restore a healthy balance of "friendly" bacteria and other microbes. Food Sources: dairy products such as yogurt, buttermilk, and kefir, soy sauce (if unpasteurized), tempeh (soybean cake), miso (soybean paste), and kombucha (tea). Prebiotics-Prebiotics are primarily undigested carbohydrates that healthy bacteria use to boost their growth in the large intestine. may prevent and treat diarrhea and colon cancer, boost the absorption of minerals, reduce levels of fat in the blood, and help control blood glucose. Food Sources: Wheat, Barley, Breast Milk, Onion, Leeks, Garlic, Chicory, Oats, Lentils, Black Bean, Kidney beans, Soybeans, rye, etc.

What are ultraprocessed foods?

processed have multiple added ingredients and have undergone a series of steps for production from "farm to fork. Ultra-processed foods are abundant in convenience stores and check-out aisles; they include popular items such as sodas, frozen pizza and meals, packaged cookies and crackers, and packaged soups and noodles.

liver

produces bile that is required for lipid digestion and absorption

What are some of the core recommendations of the Dietary Guidelines for Americans?

recommend that Americans consume a variety of fruits, vegetables, and protein foods (including fish, poultry, legumes, nuts, and lean meats). They also recommend that we replace refined grains with whole grains and solid fats with oils and limit the consumption of saturated fat (to 10% of total calories) and sodium.

Salivary Glands

secrete saliva that moistens and lubricates food and contains digestive enzymes

gallbaldder

stores bile produced in the liver until released into the small intestine.

Identify the types of claims that can be made on food labels. How does the FDA regulate menu labeling?

that describe the level of a nutrient in a food using terms such as low, high, excellent source, light, or reduced. The FDA regulates the use of these terms to ensure that they are used consistently with all types of food products. The term healthy is considered to be an implied nutrient content claim, and products must be low in saturated fat, cholesterol, and sodium and contain at least 10 percent of the Daily Value per serving of either potassium or vitamin D.

What is the brush border?

these structures give the lining of the small intestine a brushlike appearance (when viewed with a microscope), the lining is often called the brush border.

What is the difference between undernutrition and overnutrition?

undernutrition is inadequate nourishment caused by insufficient dietary intake of one or more essential nutrients or poor absorption and/or use of the nutrients in the body. overnutrition is excess intake or imbalance of calories and/or essential nutrients relative to need that result in adverse health effects.

How can we use MyPlate to encourage a healthy eating style and design a healthy diet?

where you can access a personalized diet plan (My Daily Food Plan), with more detailed recommendations about specific foods to eat each day and each week that essentially mirror those recommendations found in the DGA. But following advice about healthy diets can be especially challenging for individuals and families who have limited access to nutrient-dense, affordable, or varied foods.

What is the Ingredients List?

which is another useful tool to use when making purchases, as it provides more specific information about what the food product contains. The ingredients must be listed in descending order of amount, measured by weight. Other label requirements include that all juices must indicate the percentage of fruit juice content, and all foods must list any ingredient that could cause an allergic reaction, such as milk, peanuts, sulfites, and eggs.

What is a bolus?

which is swallowed and passed through the throat. It then enters the esophagus, a roughly 10-inch-long muscular tube that transports the bolus of burger from the mouth to the stomach, relying on gravity and peristalsis.