lipids and fats

Lipids and FatsLipids and Fats

.

FactsFactsFats belong to a group of organic

compounds called lipids.Greasy substances that are

insoluble in waterEach gram of fat contains 9

calories.

.

FunctionsFunctionsProvide energyCarry fat-soluble

vitaminsSupply essential

fatty acidsProtect and

support organs and bones

Insulate from coldProvide satiety

after meals

.

Food SourcesFood SourcesAnimal

◦ Fatty meats and fish

◦ Dairy products◦ Whole milk◦ Egg yolk

.

Food SourcesFood SourcesPlant

◦ Vegetable oils and margarine

◦ Nuts and olives◦ Chocolate◦ Avocados

Visible and Invisible FatsVisible and Invisible Fats

Visible fats◦ Fats in foods

that are purchased and used as fats, such as butter or margarine, lard, cooking oils

Invisible fats◦ Fats that are

not immediately noticeable such as those in egg yolk, cheese, cream, and salad dressings

.

Fatty Acid ClassificationFatty Acid ClassificationMay be classified by the body’s

need for them:◦ Essential fatty acids (EFAs)◦ Nonessential

Fatty Acid ClassificationFatty Acid ClassificationMay be classified by degree of

saturation with hydrogen atoms:◦ Saturated◦ Unsaturated

Monounsaturated Polyunsaturated

.

Essential Fatty AcidsEssential Fatty AcidsCannot be synthesized by the body

and must be obtained from the dietTwo families:

1.Omega-32.Omega-6

.

Nonessential Fatty AcidsNonessential Fatty AcidsCan be synthesized by the body

Saturated FatsSaturated FatsUsually solid at

room temperatureIn general, animal

foods contain more saturated fatty acids than unsaturated

Examples: meat, poultry, egg yolks, whole milk, whole milk cheeses, cream, ice cream, butter, chocolate, coconut, palm oil

Monounsaturated FatsMonounsaturated FatsHave one place among the

carbon atoms where there are fewer hydrogen atoms attached then in saturated fats.

Lower low-density lipoprotein (LDL or “bad” cholesterol) when they replace saturated fat in one’s diet

Examples: olive oil, canola oil, avocados, cashew nuts

Recommended: 15% of total daily calories

.

Polyunsaturated FatsPolyunsaturated FatsHave two or more places

among the carbon atoms where there are fewer hydrogen atoms attached then in saturated fats.

Examples: cooking oils made from sunflower, safflower, sesame seeds, or from corn or soybeans; soft margarines whose major ingredient is liquid vegetable oil; and fish

Polyunsaturated FatsPolyunsaturated FatsFoods containing high proportions

of polyunsaturated fats are usually soft or oily

Omega-3 fatty acids (found in fish) lower the risk of heart disease.

Omega-6 fatty acids have a cholesterol-lowering effect.

Recommended: 8% or less of total daily calories

.

Trans-Fatty Acids (TFAs)Trans-Fatty Acids (TFAs)Produced when

hydrogen atoms are added to monounsaturated or polyunsaturated fats to produce a semi-solid product such as margarine or shortening

TFAs raise low-density lipoproteins (LDL) and total cholesterol.

Major source: baked goods and restaurant foods

.

Hydrogenated FatsHydrogenated FatsPolyunsaturated vegetable

oils to which hydrogen has been added commercially to make them solid at room temperature

This process, called hydrogenation, turns polyunsaturated vegetable oils into saturated fats.

Margarine and shortening are made in this way.

.

CholesterolCholesterolCholesterol is a sterol,

a fatlike substance.Exists in animal foods

and body cellsDoes not exist in

plant foodsEssential for the

synthesis of bile, sex hormones, cortisone, and vitamin D

Needed by every cell in the body

Copyright © 2007 Thomson Delmar

Learning, a division of Thomson Learning Inc.

All rights reserved. 5-18

• Your client has been diagnosed with a high cholesterol level greater than 200 mg/dL. Answer the following questions:

What risks are associated with a high cholesterol level?

What can be done to lower a high cholesterol level?

Copyright © 2007 Thomson Delmar Learning, a division of Thomson Learning Inc. All rights reserved.

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• High cholesterol leads to atherosclerosis, a cardiovascular disease in which plaque(fatty deposits containing cholesterol and other substances) forms on the inside of artery walls. This can lead to heart attacks and strokes.


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• Reduce the amount of total fat, saturated fats, and cholesterol.

• Increase monounsaturated fats in the diet, lose weight, and exercise.

• Increase consumption of soluble dietary fiber.• Medication may be prescribed in some cases.

Daily cholesterol intake should not exceed 300 mg.


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LipoproteinsLipoproteinsIn the initial stages of fat

absorption, bile joins with the products of fat digestion to carry fat.

Later, protein combines with the final products of fat digestion to form special carriers called lipoproteins.

Lipoproteins carry the fat in the blood to the body cells.

LipoproteinsLipoproteinsClassified according

to mobility and density

Types◦ Chylomicrons◦ Very-low-density

lipoproteins (VLDLs)

◦ Low-density lipoproteins (LDLs)

◦ High-density lipoproteins (HDLs)

Low-Density Lipoproteins Low-Density Lipoproteins (LDLs)(LDLs)Composed of 45% cholesterol with

few triglyceridesCarry most of the blood cholesterol

from the liver to the cellsElevated blood levels greater than

130 mg/dL of LDL are thought to be contributing factors in atherosclerosis.

“Bad” cholesterol

High-Density Lipoproteins High-Density Lipoproteins (HDLs)(HDLs)Carry cholesterol from the cells to

the liver for eventual excretionLevels of HDL greater than 35

mg/dL are thought to reduce the risk of heart disease

Exercise, maintaining a desirable weight, and giving up smoking are all ways to increase one’s HDL

“Good” cholesterol

Fat AlternativesFat AlternativesOlestra

◦ Made from carbohydrates and fat

◦ FDA approved for use in snack food

◦ Government requires that food labels indicate olestra “inhibits absorption of some vitamins and other nutrients”

◦ Should be used in moderation

◦ Contains no calories; can cause cramps and diarrhea

Fat AlternativesFat AlternativesSimplesse

◦ Made from egg white or milk protein

◦ Can be used only in cold foods

Oatrim◦ Carbohydrate-based;

derived from oat fiber◦ Can be used in baking

but not frying

(continued)

Dietary RequirementsDietary RequirementsDeficiency symptoms occur when

fats provide < 10% of total daily calories

The Food and Nutrition Board’s Committee on Diet and Health recommends that people reduce their fat intake to 30% of total calories.

Dietary RequirementsDietary RequirementsAmerican Heart Association’s

newest recommendation is to consume ≤ 7% of saturated fats, 8% polyunsaturated fats, and 15% monounsaturated fats.

At present, 36% of calories in U.S. diets is derived from fats.

(continued)

Chef’s TipsChef’s TipsMost fish is lower in fat,

saturated fat. And cholesterol than are meat and poultry

Chicken is twice as fatty as turkey

White meat with skin and dark meat are higher in fat

If buying ground chicken, make sure that it is made only from skinless breast for the least amount of fat

Chef’s TipsChef’s TipsTrimmed veal is leaner

than skinless chickenWhen choosing beef,

you will get the least fat from eye of round, followed by top round and bottom round

Cooking techniques to reduce fat include roasting, grilling, broiling, sauteing, poaching, and braising

Steps in Cooking with Less Steps in Cooking with Less FatFat1. Choose a lean cut (fish, chicken breast,

trimmed meat)2. Order a quality product3. Trim the meat of visible fat4. Use flavorful rubs and marinades to allow

new and creative options (rubs combine dry ground spices such as cinnamon, and finely cut herbs, such as cilantro)

5. Choose a cooking method that will produce a flavorful, moist product, and that adds little or no fat to the food

6. Flavor the dish7. Make the plate attractive

ConclusionConclusionFats provide energy, carry

essential fatty acids and fat-soluble vitamins, protect organs and bones, insulate from cold, and provide satiety after meals.

Composed of carbon, hydrogen, and oxygen and are found in both animal and plant foods

ConclusionConclusionEach gram of fats provides 9

calories.Digestion occurs primarily in

small intestines.An excess of fat in the diet can

result in obesity and possible heart disease or cancer.

Prepared by :Prepared by :

Jamaldin, Kayzel Pearl

lipids and fats

Health & Medicine

Transcript of lipids and fats