The Lipid Family

Lipids Lipids are a family of chemical compounds in every living cell…both in foods and in the human body. 2 typed of lipids are especially important in nutrition because of how they affect health Triglycerides (aka fats) Sterols (aka cholesterol)

FATS Fats are greasy substances…either solid or liquid Fats will not dissolve in water Liquid fats are called OILS High Fat Foods include: butter, margarine, oils, cream, salad dressings, gravies, fried foods, some baked goods, ice cream, nuts and seeds, egg yolks, whole milk, some cheeses, and meat products, including bacon, sausage, and hot dogs

Visible Fats Some Fats are easy to see… the white portions around meats are fat fats in butter, margarine, and oil are also apparent

Invisible Fats Many foods contain fats that cannot be seen because they are part of the food’s chemical composition Egg yolks, nuts, whole milk, baked goods, and avocados do not look greasy or oily yet they are all high in fat. You cannot judge the amount of fat in a food by appearance alone

Adipose Cells much of the fat eaten in foods is converted and stored throughout the body ADIPOSE CELLS are the warehouses for this fat The cells in adipose tissue grow larger as they store additional fat

Why Fats are Needed Fats are not all ‘bad’…they have several important functions in the body… Fat helps the body absorb vitamins A, D, E, and K Body fat serves as a reserve of energy Body fat cushions and protects the heart and other vital organs Body fat under the skin provides insulation for warmth Fat is a component of cell membranes Fats move slowly thru the digestive system, so they help you feel full longer after eating

Structure of FATS Fats are made from chemical structures known as fatty acids. It takes 3 fatty acids plus glycerol to make a triglyceride Tri means three

Degree of Saturation a difference among fatty acids is their degree of saturation. The chemical structure of a fatty acid includes hydrogen. When a fatty acid contains all the hydrogen it can chemically hold, it is a SATURATED FATTY ACID.

Missing hydrogen sometimes hydrogen is missing from a fatty acid structure, creating an unsaturated fatty acid Monounsaturated fatty acid — if only one hydrogen unit is missing (Mono means one) Polyunsaturated fatty acid — if 2 or more hydrogen units are missing (Poly means many)

Solid vs. Liquid Fats that are solid at room temperature are comprised mostly of Saturated Fatty Acids example: butter and the fat on meat Fats that are liquid at room temperature are comprised mostly of Unsaturated Fatty Acids corn oil and olive oil

Essential Fatty Acids Your body cannot make all the fatty acids it needs, so some are considered essential and must be obtained thru foods. Linolenic acid aka Omega-3 Fatty Acid can be found in fish oils, fatty fish, also in plant sources such as flax seed and walnuts this acid lowers the risk of heart disease

Fat Digestion The digestive process breaks fats down thru a complex series of steps Fats are mainly digested in the small intestine…the gall bladder releases bile into the small intestine which break the fats into fatty acids Fatty acids are then absorbed into the bloodstream where they travel to tissues that need them Some Fatty Acids don’t travel alone, so they team up with protein and form chemical packages called LIPOPROTEINS to travel thru the bloodstream

Cholesterol Cholesterol  fat-like substance present in all body cells and is needed for many essential body processes Cholesterol is used for digesting fat and making vitamin D, as well as making some hormones and building cells Too much cholesterol is linked to heart disease Your body makes all the cholesterol that you need, but you also get cholesterol from foods All foods from animal sources contain cholesterol

LDL and HDL Like some fats, Cholesterol is transported thru the bloodstream in 2 types of lipoprotein packages… HDL LDL

LDL Low-Density Lipoprotein Takes cholesterol from the liver to wherever it is needed in the body If too much LDL is circulating, excess amounts can build up in artery walls increasing the risk of heart disease and stroke Therefore LDL is usually called ‘bad’ cholesterol

HDL High-Density Lipoprotein It picks up excess cholesterol and takes it back to the liver for excretion, keeping the cholesterol from harming the body Therefore it is known as ‘good’ cholesterol

HDL & LDL On a blood test, you want your level of HDL to be high and your level of LDL to be low

Saturated Fat Foods with saturated fat raise LDL (bad) cholesterol in the bloodstream Fatty meat, poultry skin, whole milk dairy products, tropical oils (coconut oil, palm oil)

Polyunsaturated Fat Foods with polyunsaturated fat may help lower cholesterol levels if they are used instead of saturated fats. Seafood, Vegetable oils (corn oil, soybean oil, safflower oil)

Monounsaturated Fat Foods with monounsaturated fat appear to lower LDL (bad) cholesterol levels and may help raise levels of HDL (good) cholesterol Olives, olive oil, avocados, nuts, peanut oil, canola oil

Joke… When is a vegetable oil not an oil?

HaHaHa! When it’s hydrogenated! Lets talk about why that is funny…

Hydrogenation The chemical process of hydrogenation turns veggie oils into SOLIDS. The missing hydrogen is added to the unsaturated fat, which increases saturation Shortening and Margarines are examples

Hydrogenation…Why? Food producers often use hydrogenated fats to give foods a longer shelf life and extra flavor. Many restaurants use them when frying food But there is a health price to pay… Hydrogenation turns trans fatty acids also called trans fats. Trans fats function like saturated fats in the body…they increase LDL and may lower HDL

Where to find Trans Fats Margarine Salad dressings Crackers Snack foods Baked goods Fast foods Convenience foods

How to ID trans fats… Look for these on the food label… Vegetable shortening Hydrogenated Partially hydrogenated

How much Fat do you need? Studies show that Americans eat too much fat and the wrong kinds. As a result their risk of heat disease and cancer increases. Since foods with fat tend to be high in calories, too much fat can contribute to overweight and obesity. Teens should get 25-35% of their calories from fat and adults should get 20-35%

Calculating how much fat Using a 2400 calorie diet as an example: 2400 x .25 = 600 calories/ 9 calories per gram =67 grams 2400 x .35 = 840 calories/ 9 calories per gram =93 grams

Control the amount of fat you eat… Eat plenty of veggies, fruits, and whole grains Choose low fat dairy products Remove skin from chicken and turkey Choose lean cuts of meats and drain off fat Watch portion sizes Choose fish rather than meat Use less butter, margarine, salad dressing, gravy, etc

www.calorieking.com How many calories should you eat each day? http://www.calorieking.com/