1. Tryglycerides (Fat) LIPIDS

2.  There are some good reasons to be concerned about fat in your diet; however, not all fats are bad – fat is essential in your daily diet.

3.  Fat is an important source of energy and supplies 9 calories per gram of fat.  The calories provided by fat should make up more more than 30% of the total calories consumed in a day. Much of the North American population is consuming closer to 40- 45%.

4. LIPID S FATS ARE PART OF A LARGER GROUPING CALLED

5.  Lipids include:  TRIGLYCERIDES: The largest class of lipids = nearly all of the fats and oils people typically eat. Comprised of carbon, hydrogen and oxygen. We will focus primarily on triglycerides because of their link to food. When we speak of fats, we are actually talking about this lipid category.

6.  Phospholipids: Able to dissolve in fat and water and therefore the food industry uses them as emulsifiers that mix fats with water – i.e. mayonnaise  Sterols: Include important compounds (acids and hormones). The most well known sterol = cholesterol (found in animal products).

7. FATTY ACIDS

8.  Fats (triglycerides) are composed of fatty acids and glycerol (an alcohol). Fatty acids are long chains of carbon atoms with hydrogen atoms attached to them. The body needs a number of fatty acids for normal growth and development. The body can make all but two fatty acids – the essential fatty acids = linoleic and linolenic.

9.  Provides heat to the body, and acts as a shock absorber for internal organs  Vitamins A, D, E, K dissolve in fat and this helps them move throughout the body  Body can store fat calories for future energy needs in tissue just under the skin  Keeps skin and hair healthy FUNCTION OF FAT (TRIGLYCERIDES) IN THE BODY

10.  There are two types of fats we obtain from our diet:  Saturated Fat  Unsaturated Fat

11.  “Saturated”, as the fatty acids contain all of the hydrogen atoms their molecular structure can hold.  Found in animal products: milk, cheese, butter, eggs and meat  Usually solid at room temperature  Tends to raise blood cholesterol levels and contribute to atherosclerosis SATURATED FAT: THE “BAD” FAT

12.  “Unsaturated”, as fatty acids are missing hydrogen atoms  Found in plants  Liquid at room temperature (oils)  Does not contain cholesterol; has actually been proven to help lower blood cholesterol levels  Monounsaturated fats lack 2 hydrogen atoms (i.e. oleic acid) – olive oil, canola oil, peanuts, (oil and butter), avocados  Polyunsaturated fats lack 4 or more hydrogen atoms (i.e. linoleic and linolenic acids) – the most healthy of the fats – sunflower oil, corn oil, soybean oil, fish, almonds, pecans UNSATURATED FAT:THE “GOOD” FAT

13.  A process called hydrogenation can change unsaturated fat (oils) into semi-solid fats by adding hydrogen to the molecules – i.e. margarine.  This is what is called “trans fat”. It might be called “partially hydrogenated fat” on a label. It stabilizes oil so it does not turn rancid and extends the shelf life of products – used often in baked goods. Trans fat raises blood cholesterol levels, the same way saturated fats do, and lowers ‘good’ cholesterol (HDL – high density lipoproteins). UNSATURATED FAT CONTINUED

14.  Tenderizing – One of the most important uses of fats in foods is tenderizing baked good. Fats coat flour particles creating a flaky, delicate, lighter texture.  Aeration – Fats add air or gas to batters and doughs in baked goods. The fat forms a bubble around air molecules which are incorporated into the batter.  Flavour – Fats carry flavour. FUNCTION OF FATS IN FOODS:

15. CHOLESTEROL

16.  Found in humans and animals  Cholesterol is not a triglyceride but a sterol; a fatty alcohol made from glucose or saturated fatty acids.  Cholesterol is vital in producing vitamin D and some hormones and it also strengthens cell membranes  The liver makes all the cholesterol the body needs  The cholesterol we gain from our diet (in saturated fats – animal products) is useless and harmful. Foods high in cholesterol = red meat, lobster, veal, egg yolk, liver

17.  Cholesterol in the blood contributes to plaque which can lodge in artery walls in and around the heart, reducing blood flow. This can lead to atherosclerosis (hardening of the arteries – a build up of plaque along the inner walls of the arteries). This contributes to heart disease, heart attack and stroke.  Risk facts contributing to the above = DIET(!!), age, gender, race, family history, smoking, excess weight, inactivity and stress

18.  Cholesterol and other lipids are carried in the blood stream by a protein, The combination of the two is known as a lipoprotein. LDL & HDL CHOLESTEROL

19.  Lipoproteins that transport cholesterol from the liver to other tissues are LDL (low density lipoproteins) meaning low in protein and higher in lipids.  On the return trip to the liver, lipoproteins are higher in protein than lipids, making them more dense, therefore, high density lipoproteins (HDL). HDL return cholesterol to liver for breakdown and disposal  Since LDL have a greater percentage of cholesterol (lipids), an elevated LDL level = risk of heart disease  An HDL level that is too low also indicates risk. Those with high levels of HDL have a decreased risk of heart disease.

20.  Omega-3 has been shown to promote heart health (lowering the risk of heart disease) in two ways: 1.Omega-3 make it more difficult for plaque to form or clump. 2.Omega-3 make plaque less sticky and less likely to collect in the arteries. Sardines, salmon, tuna, herring, cod and other ocean fish are highest in omega-3. OMEGA-3 FATTY ACIDS