Continuing with the trend of talking about specific nutrients, today is all about lipids, or what we call fats. Like carbohydrates, there are many diets that wish to limit or extinguish our fat intake in order for weight loss to occur. But again, like I talked said on Monday, it is not healthy or beneficial for us to completely eliminate specific nutrients from our daily consumption. Instead, we should work to better understand what lipids are, how they affect us, the transformations lipids have gone through with chemical alternations, and how lipids effect exercise.
First, it is important to recognize that there are major differences between the amount of healthy body fat for males and for females. Females need and have a much higher average body weight that comes from fat, 25% to be exact, unlike the 15% average body weight as fat for males.
Lipids are extremely similar structurally to carbohydrates. The main difference is in the number of hydrogen atoms there are when there is one atom of oxygen. Typically, we say there are about 18.3 hydrogen atoms to one oxygen atom. Carbohydrates had a 2:1 ratio. This does not necessarily mean that there is an 18.3:1 ratio for lipids, rather this is just an average because each kind of fat has a different number of hydrogen atoms attached to the oxygen atom. That is how we can define different kinds of fats. Lipids can be found in both animal and plant products; such as in poultry, fish, red meat, dairy, beans, flour, and even a little in fruits and vegetables. While eating plant products contributes about 34% of our daily lipid intake, animal sources contribute 66%!
There are many different types of lipids that are important to distinguish from each other. While there are different types, the number of calories gained per gram of fat on average is the same: 9 calories per gram of fat. One type of fat is simple fat or triglycerides. Triglycerides are formed from three carbon sugars and three fatty acids. They can mainly be found in almonds (54%), cheese (30%), avocado (16%), and milk (the percentage depends on the percent milk you buy… whole milk is 4%, 2% milk is 2%, and non-fat or skim milk is 0%). Triglycerides are formed through esterification, where increased blood levels of fatty acids and glucose cause high levels of insulin. This insulin, then facilitates synthesis of triglycerides. Triglycerides are then broken down through lipolysis in adipocytes (or fat) cells. This occurs during low to moderate exercise, low calorie dieting or fasting, and cold stress (shivering).
Fatty acids contain three more sub categories of fat that are listed on every nutritional facts table; saturated, unsaturated, and essential. Saturated fats have a chemical makeup where there are only single bonds between the carbon chain and the molecule is holding as many hydrogen atoms as possible, thus explaining why it is called saturated. This kind of fatty acid can be found primarily in animal products such as beef, pork, chicken, egg yolks, butter, cheese, and more. One easy way to know if it is a saturated fat is if the product stays in a non liquid form at room temperature and is greasy to the touch.
Unsaturated fatty acids, on the other hand, has a chemical makeup where there is one or more double bonds within the carbon chain and the molecule is unsaturated with respects to the number of hydrogen atoms attached. So there is still room for more hydrogen atoms. A mono-unsaturated fatty acid has one double bond and is found in products such as olive, canola, and peanut oil. Poly-unsaturated fatty acids contain two or more double bonds and are found in products such as safflower, sunflower, soybean, and corn oil. While some will claim that mono-unsaturated fatty acids are better than poly-unsaturated fatty acids, it is actually the poly-unsaturated fatty acids that are better for you!
While it would be easy to just tell you to eat one type of fat and no others, it would also be impossible because every kind of food contains more than one kind of fat. For example, butter contains 66% saturated fat, 4% poly-unsaturated fat, and 30% mono-unsaturated fat. Avocado oil, on the other hand, contains 12% saturated fat, 14% poly-unsaturated fat, and 74% mono-unsaturated fat. Our body handles these two kinds of fatty acids in a different way and it is vital to our health that we know the difference. Through many years of research, it has been found that saturated fatty acids correlate to heart disease, high blood pressure, stroke, and cardiovascular disease. Unsaturated fatty acids, however, correlate with a reduction in incidence of all of these. Therefore, you want to eat primarily from the unsaturated family of fatty acids.
A final type of fatty acid are essential fatty acids. These fatty acids cannot be synthesized in the body and thus are essential to get through our diets. They are necessary to serve as precursors for other types of fatty acids. One example is linoleic acid, which can be found in cooking oil.
Through experimenting with fatty acids, food scientists have created a whole slew of new , bad for you products. One technique used in order to create margarine or lard is hydrogenation. Since oils exist in liquid form and contain unsaturated fatty acids, hydrogenation changes these oils into semisolid fats by adding liquid hydrogen to the oil, reducing the double bonds in the unsaturated fats to single bonds and causing the oil to behave like a saturated fat instead. Through hydrogenation of vegetable oils, trans-fatty acids were created and can now be found in white bread, crackers, potato chips, French fries, and more. Trans-fatty acids are considered to be possible links in cardiovascular disease. So stay away from them!
Omega-3 Fatty Acids, on the other hand, are a cardiovascular disease protective, by preventing blood clot formation on the walls of arteries. Omega-3s can be obtained from the oils found in shell fish, cold-water tuna, salmon, herring, sardines, mackerel, and sea mammals.
Aside from fatty acids, there are two other main categories for lipids; compound lipids and derived lipids. Compound lipids are those like phospholipids found in nuts and wheat germ, glycolipids, and lipoproteins. Lipoproteins, which handle the transportation of cholesterol, have four smaller divisions; HDL (transport cholesterol from arteries), LDL (transport cholesterol to arteries), VLDL (transport cholesterol to arteries), and Chylomicron (metabolized in the liver and stored in adipose tissues).
Cholesterol is the main derived lipid. Cholesterol comes from animal tissue and shares similar characteristics as fatty acids. Some cholesterol is already produced in the body; about .5 to 2 grams a day, but more can be formed with diets high in saturated fats. Cholesterol functions as a plasma membrane builder; a synthesizer of vitamin D, adrenal gland and sex hormones, and bile; as well as for organ and tissue formation during fetal development. When consumed in the diet, about 55% of the cholesterol we consume is absorbed and the rest is excreted. Of the 55% absorbed, 45% is synthesized. It is recommended that we consume about 300 mg of cholesterol per day, however most Americans way surpass this number. Just a single large egg with the yolk contains about 213 mg of cholesterol alone!
Too much cholesterol consumption does have a major downside: increased risk of heart disease! If a person consumes too much cholesterol, it can begin to get deposited in the lining of the walls of the arteries and then will become calcified along with saturated and trans-fatty acids. When this happens, the arteries (particularly those in the coronary vessels of the heart) can become blocked, leading to a heart attack. This building up in the arteries is believed to be linked with high intake of cholesterol or saturated fats. So the first line of defense in protecting ourselves from risk of heart attack is to lower the amount of cholesterol we consume on a daily basis. It is also important to be careful of the kinds of lipoproteins we consume because these help transport cholesterol either to or from the heart. HDL is the good kind of lipoprotein, carrying cholesterol away from the heart. LDL and VLDL are the bad lipoproteins that carry cholesterol to the heart! Interestingly, HDL carries can actually increase with more exercise!
So what actually happens when we consume lipids? The dietary fat first goes into the small intestine where it is broken down. Then it will be transported either into the intestinal cell wall or to fat carriers such as chylomicrons. These carriers will then send the fat into the muscle, into adipose (or fat) cells, or into the liver. Inside the liver, the fats are further degraded into blood lipoproteins and are then put into body tissues. Most of the energy from fats are stored as triglycerides which are then stored in adipose cells. These cells work to synthesize and store fats during periods of food uptake and break down the fat between meals or during exercise. Along with energy, the fat cells and stored fats also contribute to protection and insulation, vitamin carrying, and satiety.
Today, the average American consume about 15% of their total calories as saturated fats per year, most of which is from animal products. Since we don't know exact amount of how much fat to consume, a recommendation is to keep the fats in your diet down to about 20% or less, most of which should be unsaturated fats. One more thing to be very careful of is fake fats, or fat substitutes. These run the rist of depleting fat soluble vitamins, depleting the blood levels of vitamin K (blood thinning vitamin) that raises the risk of cancer, and increasing diarrhea and cramping.
Finally, I want to talk about how lipids work with exercise. In order to burn more fats than carbohydrates, we must exercise at lower intensities. In this way we can lengthen the amount of time spent being active and increase the percentage of fat that is used as fuel. Therefore, the volume of exercise is more important for burning fat!
So next time you go to the grocery store, do not only look at the types of carbohydrates located in your products (remember to look for more complex carbohydrates than simple sugar), but also take a look at the fats in the products. Make sure you select for those that have a much higher unsaturated fat concentration and also check on the cholesterol in the products you are buying… your heart will thank you for it!
Today's Workout: Get your swim suit and prepare for another tough swim workout today. We are going to do the same IM workout as last week.
200 warm up
50 Fly Kick
50 Fly Twitch (25 fly, 25 free)
50 Back Kick
50 Back Twitch
50 Breast Kick
50 Breast Twitch
50 Free Kick
50 Free Twitch
Repeat the set of eight 50s
200 cool down
Total: 1200 Yards/Meters
Today's Food Tip: Next time you're thinking of stopping through a fast food drive through for a fast dinner, direct your car to your nearest grocery store instead. Browse through the isles until you can find something that sounds good and healthy. Keep health on your mind while you shop and look for something that contains some sort of veggie. Then bring it home and make it up yourself. In doing this, you will not only be participating in healthy eating, you will also save yourself some cash!
Today's Relaxation Activity: Pick one of your favorite TV shows and sit down and enjoy it today! Best of all, enjoy a show with someone else… family or friend.
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