In this weeks episode we talked about dietary fat. Is a low-fat diet really as healthy as we are led to believe? Are all fats bad? What types of fats should we avoid? What types of fats are the healthiest?
In this episode we covered:
0:00 – Introduction
3:40 – Saturated Fat: Coconut Oil
5:28 – What are Saturated Fatty Acids?
5:45 – What are Unsaturated Fatty Acids?
6:05 – Is Saturated Fat Unhealthy?
6:45 – Short-chain, Medium-chain, Long-chain, and Very long-chain Fatty Acids
7:40 – Caller Question – What is healthier butter or margarine?
12:40 – Short-chain, Medium-chain, Long-chain, and Very long-chain Fatty Acids
17:54 – Sources of Saturated Fat
18:54 – What oils are the healthiest?
19:20 – What is the role of fatty acids?
19:55 – What are Trans-Fats, Partially Hydrogenated Oils?
20:52 – Caller Question – What is healthier skim milk or whole milk?
27:40 – What are some sources of trans-fats?
28:25 – What are some other names for trans-fats?
29:17 – Why are trans-fats used?
30:05 – Food labelling – Low Fat, Fat Free, Reduced Fat, Light, Lean, Extra Lean
33:30 – How to choose healthy milk
36:40 – What are the best cooking oils?
Links we discussed:
Saturated fat is fat that consists of triglycerides containing only saturated fatty acids. (A triglyceride is a combination of a glycerol and 3 fatty acids) Saturated fatty acids are chains of carbon atoms that are fully “saturated” with hydrogen. They have no double bonds. Unsaturated fat consists of fatty acids that do have double bonds.
So, Fatty acids that have double bonds are known as unsaturated. Fatty acids without double bonds are known as saturated. For many years we were told that saturated fats were dangerous and that fats like canola oil were good for us….wrong!
Fatty Acids also differ in length.
Fatty acid chains differ by length as well as in saturation. This is important because most of us have been told that saturated fat is bad and that unsaturated fat is good. In fact, the length of the fat may be even more important.
Length is categorized as short to very long
- Short Chain fatty acids (SCFA) are (always saturated) fatty acids tails of fewer than six carbons. Found mostly in butter fat from cows or goats. (microbes good for immune systems)
- (MCFA) are fatty acids tails of 6–12 carbons, which can form medium-chain triglycerides. Found in coconut fat
- Long-chain fatty acids (LCFA) (Saturated, monounsaturated or polyunsaturated) are fatty acids with tails 13 to 21carbons. Found in beef, olive oil, black current oil
- Very long chain fatty acids (VLCFA) (Highly unsaturated) are fatty acids with tails longer than 22 carbons. Found in Fish oil (EPA, DHA) very important in the functioning of the nervous system.
Short and Medium chain fatty acids do not store as fat in human beings, whereas, long and very long chain fatty acids do.
Unlike other fatty acids, MCFA are absorbed directly from the intestines into the portal vein and sent straight to the liver where they are, for the most part, burned as fuel much like a carbohydrate. In this respect they act more like carbohydrates than like fats.2
Other fats require pancreatic enzymes to break them into smaller units. They are then absorbed into the intestinal wall and packaged into bundles of fat and protein called lipoproteins. These lipoproteins are carried by the lymphatic system, bypassing the liver, and then dumped into the bloodstream, where they are circulated throughout the body. As they circulate in the blood, their fatty components are distributed to all the tissues of the body. The lipoproteins get smaller and smaller, until there is little left of them. At this time they are picked up by the liver, broken apart, and used to produce energy or, if needed, repackaged into other lipoproteins and sent back into the bloodstream to be distributed throughout the body. Cholesterol, saturated fat, monounsaturated fat, and polyunsaturated fat are all packaged together into lipoproteins and carried throughout the body in this way.
In contrast, medium and short-chain fatty acids are not packaged into lipoproteins but go straight to the liver where they are converted into energy. Ordinarily they are not stored to any significant degree as body fat.
Short and Medium-chain fatty acids produce energy. Other dietary fats produce body fat.
Various fats contain different proportions of saturated and unsaturated fat. Examples of foods containing a high proportion of saturated fat include animal fats such as cream, cheese, butter, and ghee; suet, tallow, lard, and fatty meats; as well as certain vegetable products such as coconut oil, cottonseed oil, palm kernel oil, chocolate, and many prepared foods. Although cottonseed oil is high in saturated fat, it should be avoided due to the fact that it is genetically modified.
In particular, heart and skeletal muscle prefer fatty acids. The brain cannot use fatty acids as a source of fuel; it relies on glucose or ketone bodies.
Trans fats (or trans fatty acids) are created in an industrial process that adds hydrogen to liquid vegetable oils to make them more solid. Another name for trans fats is “partially hydrogenated oils.” Look for them on the ingredient list on food packages.
Trans fats raise your bad (LDL) cholesterol levels and lower your good (HDL) cholesterol levels. Eating trans fats increases your risk of developing heart disease and stroke. It’s also associated with a higher risk of developing type 2 diabetes.
Trans fats can be found in many foods – but especially in fried foods like French fries and doughnuts, and baked goods including pastries, pie crusts, biscuits, pizza dough, cookies, crackers, and stick margarines and shortenings. You can determine the amount of trans fats in a particular packaged food by looking at the Nutrition Facts panel. You can also spot trans fats by reading ingredient lists and looking for the ingredients referred to as “partially hydrogenated oils.”
Small amounts of trans fats occur naturally in some meat and dairy products, including beef, lamb and butterfat. It isn’t clear; though, whether these naturally occurring trans fats have the same bad effects on cholesterol levels as trans fats that have been industrially manufactured.
Companies like using trans fats in their foods because they’re easy to use, inexpensive to produce and last a long time. Trans fats give foods a desirable taste and texture. Many restaurants and fast-food outlets use trans fats to deep-fry foods because oils with trans fats can be used many times in commercial fryers.
What exactly does Low Fat Mean?
Fat Free – Less than 0.5g of fat per serving
XX% Fat Free – Must also meet the low fat claim (below)
Low Fat – 3g or less per serving; or 3g per 100g for a meal or main dish, and 30% of total calories or less
Reduced Fat – 25% less fat than food it is being compared to
Low Saturated Fat – 1g or less and 15% or less of calories from saturated fat
Light/Lite – 50% less fat or one-third fewer calories than the regular product
Lean – Less than 10g of fat, 4.5g of saturated fat and 95mg of cholesterol per 100g of meat, poultry or seafood
Extra Lean – Less than 5g of fat, 2g of saturated fat and 95mg of cholesterol per serving and per 100g of meat, poultry or seafood.
Low Cholesterol – 20mg or less per serving and 2g or less saturated fat per serving
Cholesterol Free – Less than 2mg per serving and 2g or less saturated fat per serving
Less Cholesterol – 25% or less than the food it is being compared to, and 2g or less saturated fat per serving
Low Calorie – 40 calories or less per serving
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