GCC NTR 102- Exam 2

HDL

"good" cholesterol, or high-density lipoproteins (HDLs). HDL contains a lot of protein, so rather than delivering cholesterol around the body, HDL picks up as much excess cholesterol as it can from the cells and tissues and takes it back to the liver, which then either uses the cholesterol to make bile acids, excretes it directly into bile, or recycles it. This action is thought to explain why high levels of HDL are associated with low risk for heart disease.

dietary fiber

*Dietary fiber is undigestible carbohydrates that are present naturally in intact plant foods. Fibers include cellulose and hemicellulose, which make up plant cell walls and impart structure to the plant. Fiber-rich foods are numerous and include whole grains and vegetables such as broccoli and green beans. Humans lack the digestive enzymes to break down plant fiber, so this material passes undigested through the digestive tract. The best measure to identify healthful whole grain foods, Mozaffarian found, was a total carbohydrates to fiber ratio of 10:1 (or less). This is approximately the ratio of total carbohydrate to fiber in whole wheat flour. Foods with a ratio higher than this are likely to contain added sugars and refined grains. For example, a product with 40 grams of carbohydrates and 5 grams of fiber would have a ratio of 8:1, which is less than 10:1. This is a favorable ratio. This measure tends to identify foods that have significant whole grains, low sodium, low trans fats, and low added sugar—in short, the healthiest products.

Benefits of fiber

-Fiber (particularly insoluble fiber) is healthful in part because it softens stools and thereby helps maintain regular bowel movements and reduces the risk of hemorrhoids and diverticular disease. Insoluble fiber has also been shown to decrease the risk of diabetes. -A higher intake of soluble fiber has been shown to reduce the risk of coronary heart disease. Diets high in soluble fiber also slow the emptying of food from the stomach into the small intestine, which may extend the sensation of fullness following a meal. Many soluble fibers also slow digestion and absorption, and reduce the rise in blood glucose following a carbohydrate-containing meal, which may improve blood glucose control in those with diabetes.

Protein needs

10-35%

Recommended fat intake

20-35%

Protein energy

4kcal per 1 gram

Alcohol Serving Recommendations Metabolism Digestion and absorption Benefits and drawbacks Populations who should avoid (pg 447)

Alcohol use and overuse is another issue that is often associated with the college years. People consume alcoholic drinks for many reasons—to socialize, celebrate, relax, escape, and as part of cultural and religious practices. According to surveys, 56% of the U.S. adult population reports having consumed alcohol in the past 30 days. Among college students aged 18 to 22 years, the percentage is slightly higher: about 60% of college students have reported drinking alcohol. However, the prevalence of both binge drinking and heavy drinking in college students is far higher than the general adult population. According to the National Institute on Alcohol Abuse and Alcoholism (NIAAA), "abusive and underage college drinking are significant public health problems, and they exact an enormous toll on the intellectual and social lives of students on campuses across the United States." Alcohol is the common name for ethanol, a potentially intoxicating ingredient found in beer, wine, and liquor. Alcohol is not a nutrient, but does provide energy in the form of calories (7 kcal per gram). It has potent druglike effects, acting as a central nervous system depressant. Microscopic yeast obtain energy from simple sugars in grains or fruit via a metabolic pathway called fermentation, which produces alcohol and carbon dioxide. The carbon dioxide may be released into the air, or the carbon dioxide may be trapped in the beverage causing it to be carbonated, as when beer is brewed. Beer is made by the fermentation of grains; wine is made from grapes or other fruit. Gin, rum, vodka, and whiskey are distilled, which involves heating a fermented mixture and then cooling it to condense the alcohol content into a more concentrated liquid form. A standard alcoholic drink is comprised of 14 grams (0.6 fluid ounces) of pure alcohol (ethanol), which can typically be found in 12 ounces of beer, 5 ounces of wine, or 1.5 ounces (a "shot") of 80-proof distilled spirits or liquor. The alcohol content of liquor is half the proof, so 80 proof means 40% alcohol. While defining a "standard" drink is useful for establishing and following health guidelines, in practice, the alcohol content in a typical serving varies significantly. Many cocktails may contain the alcohol equivalent of three or more standard drinks. (INFOGRAPHIC 19.5) Alcohol is readily absorbed into the bloodstream through diffusion and then is transported to the body's cells and tissues and dispersed throughout the water-containing portions of the body. About one-fifth of all alcohol consumed is absorbed through the stomach; the rest is absorbed in the small intestine. When consumed in moderate amounts, alcohol is metabolized primarily in the liver by a two-step process to form acetate. In the first step, the enzyme alcohol dehydrogenase converts alcohol to acetaldehyde, which is a highly reactive and toxic compound that can damage cellular components, including DNA. Acetaldehyde is then converted to acetate by the enzyme acetaldehyde dehydrogenase, and acetate then disperses to tissues throughout the body where it is converted to acetyl-coenzyme A, which can be used as a source of energy in the liver and elsewhere in the body. With higher levels of alcohol intake, the excessive amount of acetyl-coenzyme A that is produced in the liver results in high levels of fat synthesis that can cause a fatty liver, and eventually cause liver damage. Most alcohol is metabolized to acetate in the liver, but a small amount can also be metabolized in the stomach by the same two-step process, while even smaller amounts are excreted through our breath, sweat, and urine. The concentration of alcohol in breath and urine mirrors the concentration of alcohol in the blood, so the blood alcohol concentration (BAC) of an individual can be determined by measuring the amount of alcohol in the breath. The BAC is the standard means of assessing the extent of a person's alcohol impairment; a BAC of 0.08% is the legal limit for intoxication in the United States for drivers 21 years and older. A woman weighing 130 pounds easily exceeds the legal limit after consuming the equivalent of two alcoholic drinks. Potential benefits of alcohol Alcohol consumption can provide potential health benefits. However, it is important to recognize that the evidence for the beneficial effects of alcohol is not as strong as the evidence for its harmful effects. Also, the risk-to-benefit ratio of light to moderate drinking is more favorable in those older than 50 years than it is for those who are younger than 50. What is "moderate" alcohol consumption? In healthy adults, moderate alcohol consumption—defined by the Dietary Guidelines for Americans as having up to one drink per day for women and up to two for men—is associated with a reduced risk of several chronic diseases and conditions, including heart disease, stroke, diabetes mellitus, abdominal obesity, and dementia, as well as a reduction in overall mortality risk. The most significant health benefits of light to moderate drinking seem to be on the cardiovascular system, with the risk of heart disease typically being reduced by 30% to 35%, with increases in high-density lipoprotein cholesterol contributing significantly to this reduction in risk. It is important to note, however, that excessive alcohol consumption causes hypertension and impairs cardiac function. And binge drinking, even in those who typically drink only lightly, increases the incidence of heart attacks and death. Even just an occasional binge-drinking episode virtually eliminates the protective effects seen with otherwise light to moderate intakes. And although not depicted in the U.S. MyPlate, many national food guides from around the world include moderate alcohol consumption as a component of a healthful diet in adults. (Note that the definition of moderate consumption refers to the amount consumed on any single day and not the average over several days.) The most beneficial drinking pattern associated with a decrease in the risk of cardiovascular disease seems to be the consumption of one to two glasses of red wine immediately before or during the evening meal, as is practiced in many Mediterranean countries. However, it is not known if the benefits result from the alcohol itself, or from the social bonding or the avoidance of excess consumption that is promoted by this tradition. It is important to consider that the demonstrated benefits may also relate to the lifestyle habits and practices of people who consume moderate amounts of alcohol. 1 drink for man, 2 for women 12fl oz of regular beer (5%) 6-7fl oz of some craft beers 8-10%) 5 fl oz of table wine (12%) 1.5fl oz shot of 80-proof spirits (40%) 1/5 absorbed through the stomach rest in small intestines in moderation metabolized in the liver to form acetate Alcohol Absorption and Metabolism Alcohol is metabolized primarily in the liver where the enzyme alcohol dehydrogenase (ADH) converts alcohol to acetaldehyde. Acetaldehyde is then converted to acetate by acetaldehyde dehydrogenase (ALDH). Acetate can either be metabolized as a source of energy—producing carbon dioxide and water, or it can be used to synthesize fat. people who have a family history of abuse pregnant women

Regulation of blood glucose (hormones, function, organ)

Any glucose the body doesn't use to meet its immediate energy needs is stored for later use. The liver and skeletal muscles use this excess glucose to synthesize glycogen. The liver will break down this glycogen into glucose when needed to maintain normal blood sugar levels, and skeletal muscles will use it to fuel muscle contractions during intense exercise.

Names & structure of carbohydrates (simple to complex )

Depending on their size, carbohydrates can be classified as either simple or complex. Simple carbohydrates, also known as sugars, are short carbohydrates made up of one or two sugar units. Complex carbohydrates are composed of three or more monosaccharides linked together. They often take the form of long or branched chains. Humans and other animals break down complex carbohydrates into individual monosaccharides during the process of digestion. These units are absorbed by the cells of the intestine and dumped into the blood for all body cells to pick up and use for energy.

Sugar replacements

Because excess sugar consumption is also associated with chronic diseases such as obesity and cardiovascular disease, the food industry has created a handful of sugar alternatives that are regulated by the United States Food and Drug Administration (FDA), which has deemed them Generally Recognized As Safe (GRAS) for use in foods. There are two main types: those that are a source of calories, the nutritive sweeteners; and those that are not, called the non-nutritive sweeteners. Nutritive sweeteners include the polyols, which are alcohol forms of sugars. Sorbitol (the alcohol form of glucose) and mannitol (the alcohol form of mannose), are made from naturally occurring sugars in plants, and because they are poorly absorbed by the body, they provide fewer than 4 kcal per gram. Because of their poor absorption, excessive consumption of sugar alcohols often causes diarrhea. Non-nutritive sweeteners include the widely used aspartame products (Nutrasweet and Equal). Aspartame is made by linking two amino acids and, like protein, it provides 4 kcal per gram. However, it is so intensely sweet (about 200 times sweeter than sucrose) that so little is used to achieve the same level of sweetness as sucrose that it provides no significant amount of calories. Another popular non-nutritive sweetener is stevia extract (Truvia), made from the sweet leaves of subtropical stevia plants. Examples of other non-nutritive sweeteners found in foods and in the "sugar" bowl at your restaurant table include sucralose (Splenda) and saccharin (Sweet'N Low). (INFOGRAPHIC 4.8)

Relationship of carb, fat, protein

Carb- 45-65% Fat- 20-35% Protein- 10-35%

sterols

Chemically, sterols are complex lipids with four interconnected carbon rings with a hydrocarbon side chain. The most discussed sterol is cholesterol. A molecule with varied functions, cholesterol is a critical component of our cell membranes and is also needed as a precursor for the synthesis of bile acids, vitamin D, and steroid hormones such as estrogen and testosterone, but it does not provide any energy.

Limiting amino acid/complementary proteins

Eggs are a food with high protein quality; that is, eggs contain all of the nine essential amino acids in amounts and proportions that best support protein synthesis in the body. Animal foods (meat, fish, dairy, and eggs) provide high-quality protein, as do some plant foods like soy, quinoa, and amaranth. These foods are considered complete proteins in that they contain all nine essential amino acids in the appropriate proportions. In contrast, incomplete proteins are foods with lower protein quality; they lack or supply low amounts of one or more essential amino acids. Without an adequate supply of all nine essential amino acids, protein synthesis is disrupted or limited—the amino acid in the shortest supply relative to its requirement is referred to as the limiting amino acid.

Essential fatty acids

Fatty Acids the body cannot produce on its own, and must obtain through diet The body can make some of the fats it needs from the foods you eat. However, two essential fatty acids cannot be made in the body and can be taken in the diet from plant foods. These basic fats—linolenic and linoleic acid—are used to build specialized fats called omega-3 and omega-6 fatty acids.

Fatty Acid Chain

Fatty acids consist of a chain of carbon atoms with hydrogen atoms attached to each carbon atom (a hydrocarbon chain): a carboxyl group attached to one end of the fatty acid chain, and a methyl group at the other end (three hydrogens bonded to a carbon atom—also called the "omega" end of the fatty acid). Fatty acids differ in length, and so they are categorized by the length of their hydrocarbon chains, as well as in their degree of saturation (how many hydrogen atoms fill the available bonds with carbon). Short-chain fatty acids have fewer than 6 carbons; medium-chain fatty acids have 6 to 12 carbons, and long-chain fatty acids have more than 12 carbons. Both properties, degree of saturation, and chain length determine their function in the body and role in health and disease.

Recommendations for carbohydrate intake

Given the importance of carbohydrates to health, all nutrition guidelines provide recommendations for carbohydrate intake. In addition to encouraging consumption of carbohydrate-rich plant foods, the 2015 Dietary Guidelines for Americans recommends that people consume at least half of all grains as whole grains, and to increase whole grain intake by replacing refined grains with whole grains. The Institute of Medicine recommends that people consume carbohydrates within a certain range, the Acceptable Macronutrient Distribution Range (AMDR) of 45% to 65% of total calories, which is associated with a reduced risk of chronic disease while providing adequate amounts of essential nutrients. There is also a recommended dietary allowance (RDA) for carbohydrates, which is based on the amount of carbohydrates that is needed for the brain to function properly.

Vegetarian diets

Health benefits Lower total blood cholesterol levels Lower low-density lipoprotein levels Lower blood pressure Reduced cardiovascular risk Lower risk of obesity, heart disease, cancer, type 2 diabetes, and mortality Lacto-vegetarian Plant foods plus diary Lacto-ovo vegetarian Plant foods plus dairy products and eggs Vegan Semi-vegetarian (quasi-vegetarian) Only exclude red meats but eat other animal products Pescatarians Plant based with fish and shell fish Flexitarian Mostly plant based but occasionally eat meat High intake of Dietary fiber Vitamins C, E, and folate Magnesium and potassium Antioxidants and phytochemicals Fewer overall calories Lower proportion of calories from fat Decreased consumption of processed meats Lower total blood cholesterol levels Lower low-density lipoprotein levels Lower blood pressure Reduced cardiovascular risk Lower risk of obesity, heart disease, cancer, type 2 diabetes, and mortality

Chylomicrons

In the mucosal cells, triglycerides and other dietary lipids are incorporated into a lipid transport particle called a chylomicron, which is one type of lipoprotein. Lipoproteins are protein-containing spherical particles that act as the primary carriers of lipids in blood. Lipids are not typically soluble in water and require carriers for transport, and so cannot travel freely in the bloodstream. As a result, clinical laboratory tests that monitor blood lipid levels typically measure amounts and types of lipids present in lipoproteins in blood. Unlike other lipoproteins, however, chylomicrons are so large that they cannot enter blood immediately after their formation, so they first enter the lymphatic system, which then delivers them into the bloodstream.

Diabetes type 1

In type 1 diabetes, the pancreatic cells that secrete insulin are destroyed by the body's immune system, leading to a major deficiency of insulin that typically progresses to its complete absence. Type 1 diabetes is an autoimmune disease, like celiac disease (covered in Chapter 3). In an autoimmune disease, the body's immune system attacks or destroys its own cells. Type 1 diabetes is not preventable, and between 5% and 10% of individuals with diabetes have type 1. In type 1 diabetes, the extremely low levels of insulin limit the body's ability to use glucose. To minimize the breakdown of muscle protein for energy (and prevent muscle wasting), fatty acids are released from adipose tissue. However, the brain cannot use fatty acids effectively for energy, so the liver converts some of these fatty acids into a source of energy the brain can use called ketone bodies. If the diabetes is left untreated, over time these ketones build up in the bloodstream, increasing the acidity of blood and causing a condition called ketoacidosis, which can lead to coma and death.

Effects of too much protein

Inadequate or excess protein intake can have health and metabolic consequences Ketosis

Function of lipids

Lipids play important roles in the body, such as acting as a major component of cell membranes, giving them flexibility and integrity. They also facilitate the transport of nutrients, including fat-soluble vitamins (A, D, E, and K) and phytochemicals, as well as enhancing their absorption. Adipose tissue also cushions, protects, and insulates the kidney, heart, and other organs, shielding them from temperature extremes and acting as a natural shock absorber. Fats are a concentrated source of energy, providing 9 kcal per gram, typically accounting for one-third or more of our total calorie intake. Fat is significantly more energy dense than carbohydrates and protein, which provide only 4 kcal per gram. Lipids are diverse in structure and function. We will discuss the four most common lipid classes: fatty acids, triglycerides, sterols (such as cholesterol), and phospholipids (such as lecithin). Although some use the term "lipid" interchangeably with "fat," the word "fat," more precisely, refers to triglycerides, which make up 95% of all lipids in our foods and 99% of the stored fat in our bodies.

LDL

Low-density lipoproteins (LDLs) transport cholesterol from the liver to all cells and are often referred to as "bad" cholesterol, as elevated levels are associated with an increase in the risk of heart disease

starch

Most complex carbohydrates in our diet come from plants. Depending on how the sugars are bonded together, polysaccharides in plants may function as a source of stored energy (starch) or as structural material (fiber). Starches include amylose and amylopectin, found in grains, legumes, and starchy vegetables such as peas, potatoes, and corn. Starches are a form of stored energy for the plant

polysaccharide

Oligosaccharides contain 3 to 10 linked monosaccharides, while polysaccharides are chains (or polymers) of more than 10 monosaccharides.

Trans fat

One outcome of partial hydrogenation, however, is the structure of some of the unsaturated fatty acids can be converted from its natural "cis" configuration to another known as "trans." These so-called trans fatty acids raise levels of "bad" cholesterol, and lower levels of "good" cholesterol in blood, and increase the risk of heart disease more than any other type of fat. As little as 1% of total calories from trans fats can increase the risk of heart disease, stroke, or sudden death from these and other causes. Although a small amount of trans fat is naturally present in full-fat dairy products and beef, most of the trans fat we consume comes from the partially hydrogenated oils used to make processed foods that need a longer shelf life. The majority of trans fats in the U.S. diet are found in commercial baked goods (cakes, cookies, pies, biscuits, and doughnuts), packaged snacks such as crackers and popcorn, margarine, frozen pizzas, and fried potatoes. Given the risks of trans fats, as of 2006, all Nutrition Facts Panels must include the trans fat content of food products and more recently, the U.S. Food and Drug Administration has proposed a ban on their addition to any food products. When purchasing processed foods, it is important to look beyond the grams of trans fat listed on the nutrition facts panel because foods with less than half a gram per serving can claim 0 grams trans fat. To minimize your intake of trans fats, avoid purchasing foods that list partially hydrogenated oils in the list of ingredients. Increasing awareness of the dangers of trans fats has resulted in more frequent use of fully hydrogenated oils. When oils are fully hydrogenated all double bonds are eliminated and no trans fats are produced.

phospholipids

Phospholipids, the fourth most common category of lipids (after fatty acids, triglycerides, and sterols), are also the primary component of cell membranes and the structures that transport lipids in the blood. Because the body can produce phospholipids, they are not considered an essential nutrient. Phospholipids are similar to triglycerides in structure: they have a glycerol backbone, but with two rather than three attached fatty acids. Attached at the third position is a phosphate group and one of several water-soluble "head-groups." Together the glycerol backbone, the phosphate, and the head group create a water-soluble head on the phospholipid, while the fatty acid "tails" at the other end are soluble in lipids but not in water. Phosopholipids are a critical component of cell membranes. They also play a central role in transporting lipids throughout the body. Despite their importance, they are not essential nutrients, as we are able to synthesize all that we need. This two-sided structural arrangement of phospholipids—one end water-soluble and the other end fat-soluble—allows phospholipids to suspend fat in water. The fat-soluble tails of phospholipids will surround small fat droplets, leaving the water-soluble head of the phospholipid facing outward toward the water. Placing this water-friendly coating around the lipid droplets allows them to remain stably dispersed (mixed) in the watery environment. An example of a phospholipid is lecithin. In addition to being the most abundant phospholipid in our body, lecithin is also frequently added to food products like salad dressings as an emulsifier because of its ability to keep water and lipids from separating.

Function of protein in the body

Protein has many critical roles in the body's structure and processes, including catalyzing chemical reactions (enzymes), regulating body functions (hormones), and transporting substances in the blood; also has central roles in immunity, fluid balance, and blood clotting

Lipids Common properties

Scientists have long known that what we commonly call "fats" are a subclass of lipids, a group of compounds made up of carbon, hydrogen, and a small amount of oxygen that generally can't mix or dissolve in water (they are water insoluble). Lipids play important roles in the body, such as acting as a major component of cell membranes, giving them flexibility and integrity. They also facilitate the transport of nutrients, including fat-soluble vitamins (A, D, E, and K) and phytochemicals, as well as enhancing their absorption. Adipose tissue also cushions, protects, and insulates the kidney, heart, and other organs, shielding them from temperature extremes and acting as a natural shock absorber. Fats are a concentrated source of energy, providing 9 kcal per gram, typically accounting for one-third or more of our total calorie intake. Fat is significantly more energy dense than carbohydrates and protein, which provide only 4 kcal per gram. Lipids are diverse in structure and function. We will discuss the four most common lipid classes: fatty acids, triglycerides, sterols (such as cholesterol), and phospholipids (such as lecithin). Although some use the term "lipid" interchangeably with "fat," the word "fat," more precisely, refers to triglycerides, which make up 95% of all lipids in our foods and 99% of the stored fat in our bodies.

Fat replacements

Some people who want to reduce their fat intake turn to fat substitutes, which imitate the taste, texture, and cooking properties of fats but provide fewer calories. Use of these products in place of their higher-fat counterparts, may help reduce dietary fat intake, and lower blood cholesterol, but not without potential side effects. Fat substitutes from carbohydrates, protein, and vegetable oils are considered safe; those from other substances must be tested for safety. One common substitute is Olestra, which has chemical components similar to those of triglycerides in a different configuration, causing them to not be digested or absorbed by the body. But there are consequences: The U.S. Food and Drug Administration requires any products that contain Olestra to read: "Olestra may cause abdominal cramping and loose stools. Olestra inhibits the absorption of some vitamins and other nutrients." Most people who eat a Western diet—such as Americans and many Europeans—eat plenty of fat, just not necessarily the right kinds. Much of the fat we consume has undergone a process of hydrogenation, which makes unsaturated fats more solid and stable by chemically adding hydrogen to double bonds between carbon atoms on the fatty acid chain and thus makes them more saturated. This renders them harder at room temperature and more resistant to spoiling. This process can also improve taste, texture, and increase their culinary applications.

Monosaccharides

Sugars that are made up of one sugar unit are called monosaccharides. three most abundant monosaccharides are fructose, glucose, and galactose.

*Glycemic index

The Glycemic Index is a numerical Index that ranks carbohydrates based on their rate of glycemic response (i.e. their conversion to glucose within the human body). Glycemic Index uses a scale of 0 to 100, with higher values given to foods that cause the most rapid rise in blood sugar. Pure glucose serves as a reference point, and is given a Glycemic Index (GI) of 100. Although gylcemic index can be a helpful measure to consider, it has some limitations. For example, we rarely eat carbohydrate foods in consistently the same amounts (smaller or larger amounts would alter the GI) or eat these foods by themselves. And even carbs with high GIs have less effect on blood glucose when consumed with protein, fat, or fiber, which all delay gastric emptying. Even factors such as the ripeness of a fruit or how a carbohydrate is processed can alter its GI.

Digestion & absorption

The original shape of the protein is not necessarily permanent. Heat, light, change in pH, alcohol, or motion—such as beating egg whites—will change the three-dimensional structure, a process known as denaturation. Very high fevers or extreme changes in the pH of blood may be sufficient to denature proteins within our body and cause them not to function properly. For example, heat or a change in pH could destroy the function of enzymes or damage the protein hemoglobin, which carries oxygen in the blood. It's easy to visualize protein denaturation in the kitchen—adding lemon juice to milk renders it more acidic (changes the pH), making the milk curdle. Similarly, cooking (heat) causes meat to become firm and eggs to harden. In our bodies, denaturation by stomach acid (hydrochloric acid) unfolds a food protein in the stomach. Unfolding allows the enzyme pepsin, produced by cells lining the stomach, to access the peptide bonds and increase the digestibility of the protein. Once the protein fragments enter the small intestine, enzymes released from the pancreas, known as proteases, break the strings of amino acids into peptides, short chains of amino acids. These peptides are digested further by enzymes on the surface of the intestinal mucosa, and dipeptides, tripeptides, and individual amino acids are then absorbed by mucosal cells of the small intestine with the assistance of various transport proteins. From the mucosal cells the amino acids are transported into the blood by additional transport proteins.

Triglycerides

Triglycerides are lipids made up of three fatty acid chains bound to one glycerol, a small three-carbon molecule that makes up the glycerol backbone of each triglyceride. The fatty acid chains form the "tail" of the triglyceride. All triglycerides are composed of a mix of short-chain, medium-chain, and long-chain fatty acids. They seldom contain exclusively one type of fatty acid. Triglycerides in foods supply energy and may also carry certain fat-soluble vitamins, such as vitamins A, D, E, and K (covered in more detail in Chapter 10). Since triglycerides consist of three fatty acids, they can provide essential fatty acids, the fatty acids our bodies need but cannot synthesize in sufficient amounts, and so must be obtained through our diets.

monounsaturated

Unsaturated fats are found most abundantly in plant foods, such as seeds, nuts, grains, and most vegetable oils. Fatty acids with one point of unsaturation are called monounsaturated fatty acids (abundant in olive and canola oils and nuts)

Hypoglycemia

When the pancreas becomes unable to produce insulin, muscle and adipose tissues cannot appropriately take up glucose, and blood glucose levels skyrocket—a condition known as hyperglycemia.

Proteins Amino acids (essential vs. nonessential)

amino acids are the building blocks of protein. Nine of the 20 are considered essential amino acids—we must get them from the foods we eat because they cannot be produced by the human body. The rest are nonessential amino acids—sometimes called "dispensable" amino acids—because they can be manufactured by the body.

High quality protein (complete) vs. low quality (incomplete)

complete proteins contain all 9 essential amino acids, while incomplete do not. Beans and rice. This simple complementary protein dish is easy to prepare and delicious. Most plant foods are incomplete proteins and they vary in the types and proportions of amino acids they contain. However, all the essential amino acids needed for protein synthesis can be supplied by consuming two or more "complementary" protein plant foods. Chapter 9 will further explore plant-based diets and protein complementation. An example of protein complementation is rice and beans, which have different limiting amino acids. The amino acids methionine and cysteine are low in beans, but adequately supplied in rice. And as long as complementary protein foods are consumed within the context of an overall varied and balanced diet, they don't even have to be eaten at the same meal.

Fat and health, obesity, heart disease, cancer

eat more unsaturated fats more fat leads to obesity because any excess not burned off turns to adipose tissue some fats are good for your heart some fats indirectly cause cancer

Kwashiorkor

happens a lot when children are abruptly weaned and do not get adequate nutrients from the starchy gruel that is replacing the mother's milk. Not a lot of subcutaneous fat loss, but development of edema and a fatty liver because they cannot synthesize proteins to maintain fluid balance or transport fat from the liver.

malnutrition

lack of nutrients from food

Marasmus

long term lack of protein and calories. Characterized by low body fat and muscle depletion. Can cause brain damage in developing children due to lack of needed nutrients during brain growth.

Plant protein

not complete (does not contain all 9 essential amino acids) Most plant foods are incomplete proteins and they vary in the types and proportions of amino acids they contain. However, all the essential amino acids needed for protein synthesis can be supplied by consuming two or more "complementary" protein plant foods. Chapter 9 will further explore plant-based diets and protein complementation. An example of protein complementation is rice and beans, which have different limiting amino acids. The amino acids methionine and cysteine are low in beans, but adequately supplied in rice. And as long as complementary protein foods are consumed within the context of an overall varied and balanced diet, they don't even have to be eaten at the same meal. This helps explain why strict vegetarians (vegans) can still meet their protein requirements.

disaccharide

sugars made up of two sugar units are called disaccharides.The disaccharides are made up of pairs of monosaccharides and are called lactose, maltose, and sucrose. The mammary glands of humans and other mammals synthesize lactose (galactose and glucose), which is incorporated into milk to feed offspring. Maltose is composed of two glucose units and is produced when starch is broken down in digestion. Sucrose, or "table sugar," is a disaccharide composed of glucose and fructose. We must digest dissacharides into their component monosaccharides before they can be absorbed by cells of the intestines.

polyunsaturated

those with more than one point of unsaturation are called polyunsaturated fatty acids (abundant in corn, safflower, sunflower, sesame, and soybean oils). The arrangement of the hydrogen atoms on either side of the double bonds can be in either a "cis" or a "trans" orientation, which has important health implications, as will be discussed later in the chapter.

Diabetes type 2

type 2 diabetes occurs when cells are less sensitive to the effects of insulin, even if the pancreas is able to produce normal amounts. Obesity is by far the most significant risk factor for the disease: 80% to 90% of people with type 2 diabetes are obese. In addition to having excess body fat, physical inactivity is another factor that significantly affects the risk of developing diabetes. However, genetics and lifestyle factors also potently affect an individual's risk of disease. If one identical twin has diabetes, the other twin will also have the disease 75% of the time. In addition, the risk of diabetes is higher among African-Americans, Hispanics and Latinos, American-Indians, Asian-Americans, and Pacific Islanders than among white people. Type 2 diabetes begins with the development of insulin resistance. Most often this occurs because excess adipose tissue produces hormone-like substances that circulate throughout the body and interfere with the signal that insulin sends into cells to stimulate glucose uptake. As a result, muscle and fat cells do not respond properly to insulin and poorly take up glucose from the blood. The body then needs higher levels of insulin to help glucose enter cells. The cells of the pancreas produce more of the hormone to try to meet the demand. In some insulin-resistant individuals the pancreas can no longer keep up with the increased demand for insulin, and blood glucose concentrations increase. Insulin resistance also blocks insulin's ability to adequately suppress liver glucose production, contributing further to the increase in blood glucose levels.