Nutrition 2750 Chapter 4: Lipids

The nutrition class has been discussing phospholipids. The nurse recognizes that the class has been successful when the students identify which of the following as a phospholipid?

lecithin

Chylomicrons

lipoproteins that transport absorbed lipids from intestinal cells through the lymph and eventually into the bloodstream.

A client beginning a weight loss program asks the nurse to explain the amount of fat that should be consumed each day since there are no recommendations to be found on the internet. What should the nurse respond to this client?

Limit the intake to be between 20-35% of total calories

A client beginning a weight loss program asks the nurse to explain the amount of fat that should be consumed each day since there are no recommendations to be found on the internet. What should the nurse respond to this client?

Limit the intake to be between 20-35% of total calories.

Linoleic Acid

Linoleic acid, the essential n-6 PUFA, is the most highly consumed PUFA in Western diets. The richest sources are soybean, corn, and safflower oils; poultry, nuts, and seeds are also sources. The body can make other n-6 fatty acids, such as arachidonic acid, from linoleic acid. However, if a deficiency of linoleic acid develops, arachidonic acid becomes "conditionally essential" because the body is unable to synthesize it without a supply of linoleic acid. (polyunsaturated fatty acid) *arachidonic acid, from linoleic acid; deficiency of linoleic acid develops, arachidonic acid becomes "conditionally essential" because the body is unable to synthesize it without a supply of linoleic acid.

fish oils

a common term for the long-chain, polyunsaturated omega-3 fatty acids EPA and DHA found in the fat of fish, primarily in cold-water fish.

The nurse recognizes which of the following patients are at risk for developing essential fatty acids deficiencies? Select all that apply.

patients receiving long-term lipid-free total parenteral nutrition and patients with anorexia nervosa *Patients with anorexia nervosa or receiving long-term lipid-free TPN are at risk of developing deficiencies of essential fatty acids. Patients receiving tube feedings will have essential fatty acids included in their formula. Patients status post bowel resection should be started on a diet before a deficiency can develop. Patients on a low-fat diet should be receiving adequate amounts of essential fatty acids in their diet.

The nurse is visiting a sixth-grade class to discuss nutrition. After discussing fats with the class, the nurse recognizes that they understand how fats are digested when they identify that most fat digestion occurs where?

small intestine *Most fat digestion occurs in the small intestine. A minimal amount of chemical digestion occurs in the mouth and stomach. Fat that moves into the large intestine is usually excreted in the feces.

Unsaturated Fatty Acids-2 catagories are?

*Monounsaturated Fatty Acids and Polyunsaturated Fatty Acids *fatty acids that are not completely saturated with hydrogen atoms, so one or more double bonds form between the carbon atoms. *associated with a decrease in LDL cholesterol and lowers the risk of cardiovascular events and death *fatty acids that are not completely saturated with *hydrogen atoms, so one or more double bonds form between the carbon atoms.

Bile

*a digestive juice secreted by the liver and stored in the gallbladder

Saturated Fatty Acids

fatty acids in which all the carbon atoms are bonded to as many hydrogen atoms as they can hold so no double bonds exist between carbon atoms. *only tightly packed single bonds * most are solid at room temperature * Studies now show most likely no low-density

Monounsaturated Fatty Acids (unstaturated)

fatty acids that have only one double bond between two carbon atoms-double bonds *good fat

The nurse is helping a client review his food choices. The nurse notes that this client is consuming a large amount of saturated fat. Which of the following is the client most likely eating?

red meat

low-density lipoprotein (LDL) cholesterol.

the major class of atherogenic lipoproteins that carry cholesterol from the liver to the tissues. *saturated fatty acid stearic acid has a neutral impact on LDL cholesterol *saturated fatty acids lauric, myristic, and palmitic acids increase LDL cholesterol

Trans Fats

unsaturated fatty acids that have at least one double bond whose hydrogen atoms are on the opposite sides of the double bond; "trans" means across in Latin. *Found to raise LDL *Only small amounts of trans fats occur naturally in some animal foods, such as beef, lamb, and dairy products.

phospholipids (lecithin)

* a group of compound lipids that is similar to triglycerides in that they contain a glycerol molecule and two fatty acids. *Lecithin is the best-known phospholipid * In place of the third fatty acid, phospholipids have a phosphate group and a molecule of choline or another nitrogen-containing compound. *Phospholipids are both fat-soluble (because of the fatty acids) and water-soluble (because of the phosphate group) a unique feature that enables them to act as emulsifiers. This role is played out in the body as they emulsify fats to keep them suspended in blood and other body fluids. *As a component of all cell membranes, phospholipids not only provide structure but also help to transport fat-soluble substances across cell membranes. Phospholipids are also precursors of prostaglandins.

Glycerol

* a three-carbon atom chain that serves as the backbone of triglycerides. * Fatty acids attach to glycerol molecules in various ratios and combinations to form a variety of triglycerides within a single food fat.

Fatty Acids

* organic compounds composed of a chain of carbon atoms to which hydrogen atoms are attached. An acid group (COOH) is attached at one end, and a methyl group (CH3) at the other end. COOH-CCC-CH3 * Fatty acids vary in the length of their carbon chain and in the degree of unsaturation *Fatty acids attach to glycerol molecules in various ratios and combinations to form a variety of triglycerides within a single food fat.

Digestion

*A minimal amount of chemical digestion of fat occurs in the mouth and stomach through the action of lingual lipase and gastric lipases. *The process by which the body breaks down food into small nutrient molecules *Fat entering the duodenum stimulates the release of the hormone cholecystokinin, which in turn stimulates the gallbladder to release bile (bile-an emulsifier produced in the liver from bile salts, cholesterol, phospholipids, bilirubin, and electrolytes, prepares fat for digestion by suspending the hydrophobic molecules in the watery intestinal fluid) *Most fat digestion occurs in the small intestine *lipoproteins- transport absorbed lipids from intestinal cells through the lymph and eventually into the bloodstream.

Omega and Essentional Fatty Acids

*Omega-3 (n-3) Fatty Acid an unsaturated fatty acid whose endmost double bond occurs three carbon atoms from the methyl end of its carbon chain. *Omega-6 (n-6) Fatty Acid an unsaturated fatty acid whose endmost double bond occurs six carbon atoms from the methyl end of its carbon chain. *Essential Fatty Acids- fatty acids that cannot be synthesized in the body and thus must be consumed through food. *

Alpha-Linolenic Acid

*a polyunsaturated essential fatty acid; part of the omega-3 fatty acid family *Alpha-linolenic acid, the essential n-3 fatty acid, is the most prominent n-3 fatty acid in most Western diets. (walnuts, flaxseed, chia and hemp seeds, and canola and soybean oils). *to a very limited extent, humans can convert alpha-linolenic acid to the n-3 fatty acids eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). These two n-3 fatty acids are commonly referred to as "fish oils" because they are primarily found in fatty fish, especially salmon, anchovy, sardines, tuna, herring, and mackerel. Food products fortified with EPA and/or DHA are available, such as soy milks, cooking oils, margarine-like spreads, breakfast cereals, baked goods, infant formulas, and baby food and juices.

Cholesterol is a sterol

*found exclusively in animals, with organ meats and egg yolks the richest sources *Sterols-one of three main classes of lipids that include cholesterol, bile acids, sex hormones, the adrenocortical hormones, and vitamin D.

The nurse is sharing the recommendations of the 2015-2020 Dietary Guidelines for Americans with a client. The nurse knows that this client, who has cardiac disease, should consume how much fatty fish per week?

7 ounces per week

The nurse is teaching a nutrition class with some of the clients who are having economic difficulties and unable to choose more expensive cuts of meat to limit fat intake. Which of the following should the nurse recommend that they use?

90% Lean

triglycerides

A class of lipids made of an energy-rich compound *single molecule of a glycerol backbone. (3 carbon chain) *three fatty acids attached. *occurs in 98% of fat in food *yields more calories per gram than Carbohydrates. *an individual triglyceride molecule may contain one, two, or three different types of fatty acids.

The health care provider determines that a client's vision changes are associated with a low intake of vitamin A. What should the nurse suggest to the client to increase the absorption of this vitamin?

Add carrots to a mixed salad with olive oil

Carbon Chain Length

Almost all naturally occurring fatty acids have an even number of carbon atoms in their chain, generally between 4 and 24. *Long-chain fatty acids (containing more than 12 carbon atoms) predominate in meats, fish, and vegetable oils and are the most common length fatty acid in the diet. *medium-chain (8-12 carbon atoms) *short-chain (up to 6 carbon atoms) fatty acids are found primarily in dairy products.

The nurse is reviewing the need for fatty acids with a client. The nurse recognizes that which of the following is the most prominent n-3 fatty acid in most Western diets?

Alpha-linolenic acid, the essential n-3 fatty acid

Essential Fatty Acid Deficiency

Although the body cannot make essential fatty acids, it does store them, making deficiencies extremely rare in people eating a variety of food. Those at risk for deficiency include infants and children with low-fat intakes (their need for essential fatty acids is proportionately higher than that of adults), clients with anorexia nervosa, and people receiving lipid-free parenteral nutrition for long periods. People with fat malabsorption syndromes are also at risk. Symptoms of essential fatty acid deficiency include growth failure, reproductive failure, scaly dermatitis, and kidney and liver disorders.

The nurse is teaching a group of nursing students about the body's need for fuel to function. The class is aware that fat's primary function is to fuel the body. However, which cells are not fueled by fat?

Brain. Fat is an important energy source; however, the brain cells and cells of the central nervous system rely solely on glucose for energy.

Monoglyceride

a glyceride molecule with only one fatty acid attached. *along with diglyceride added to food to keep oil and water products from separating. *insoluble in water *Both Monoglycerides and long-chain fatty acids dissolve into micelles which deliver fat to the intestinal cells. (micelles-fat particles encircled by bile salts to facilitate their diffusion into intestinal cells)

Lipids

a group of water-insoluble, energy-yielding organic compounds composed of carbon, hydrogen, and oxygen atoms. Triglycerides Phospholipids Sterols

Omega-3 Fatty Acid

a polyunsaturated fatty acid in which the closest double bond to the methyl (CH3) end of the carbon chain is three carbons away. *"fish oils" a common term used for the two types of Omega-3 fatty acids *EPA -eicosapentaenoic acid *DHA-docosahexaenoic acid

Hydrogenation

a process of adding hydrogen atoms to unsaturated vegetable oils (usually corn, soybean, cottonseed, safflower, or canola oil), which reduces the number of double bonds; the number of saturated and monounsaturated bonds increases as the number of polyunsaturated bonds decreases.

Emulsifier

a stabilizing compound that helps to keep both parts of an emulsion (oil and water mixture) from separating.

Degree of Saturation

carbon atoms in a fatty acid have four single bonds each, the fatty acid is saturated with hydrogen atoms. The majority of naturally occurring saturated fatty acids are straight-line molecules that can pack tightly together; thus, they are solid at room temperature.

A client is interested in using coconut oil instead of olive oil. What is the nurse's best recommendation to this client?

coconut oil is higher in saturated fats than olive oil

Polyunsaturated Fatty Acids (Unsaturated)

fatty acids that have two or more double bonds between carbon atoms. *good fat

The nurse is explaining the MyPlate plan to a client who is status post a cholecystectomy and needs to follow a low-fat diet. Which of the following foods are best suited to this client's dietary needs? Select all that apply.

grains vegetables fruit