Types of Lipids and Fats

Lipids: any of a class of organic compounds that are fatty acids or their derivatives and are insoluble in water but soluble in organic solvents. They include many natural oils, waxes, and steroids.

Types of Lipids:

• Phospholipids

• Sterols (Cholesterol)

• Triglycerides

Fats (solid) oils (liquid)

• 9 calories per gram

Carrying Lipids in Bloodstream

• Water and oil (fat) do not mix easily

• A unique system of fat transportation is needed

Lipoprotein: compound in the bloodstream containing a core of lipids with a shell composed of protein, phospholipid, and cholesterol. Used for lipid transportation.

Major Lipoproteins in Blood

LDL: Carries cholesterol made by the liver and from other sources to cells

HDL: Contributes to cholesterol removal from cells and, in turn, excretion of it from the body

Sterols

• Multi-ringed structure

• Do not have a glycerol backbone

• Waxy substance

• Do not readily dissolve in water

• Cholesterol: most common example of sterols (found only in animal foods)

Functions of Cholesterol

• An essential component of the cell membrane (makes the membrane more fluid)

• Produced by the liver

• Found only in animal products

• Used to form bile acids

• Forms important hormones such as estrogen, testosterone, and vitamin D.

• Can be synthesized by the body

• Your body makes all the cholesterol it needs

Two Sources of Cholesterol

Endogenous Cholesterol: Cholesterol made inside the body.

Exogenous Cholesterol: Cholesterol obtained from outside the body (i.e. food). Can only be obtained from animal sources.

Triglycerides

• the most common form of fats and oils

• A lipid composed of a glycerol molecule attached to three fatty acids.

• Sources of triglycerides come from Dietary fat and adipocyte (adipose cells)

What are Dietary Sources of Saturated Fatty Acids?

Saturated fatty acid: the fatty acid chains have all single bonds. A fat known as a glyceride is made of two kinds of smaller molecules: a short glycerol backbone and fatty acids that each contain a long linear or branched chain of carbon atoms

• Two chemical groups are found at the end of either side of the fatty-acid carbon chain include; an acid group (COOH) and a methyl group (CH3)

• Most foods containing saturated fatty acids are solid at room temperature.

• Oils rich in unsaturated fatty acids are typically liquid at room temperature.

Health Effects of Saturated Fatty Acids

• High intake of SFA increases Low Density of Lipoproteins (LDL cholesterol) levels in your blood

• Increases your risk of heart disease and stroke

Saturated Fatty Acid Intake Recommendations

• < 7-10 % total calories

• <10% of Calories for the general population

• <7% of Calories for individuals with a history of CVD

Animal-based sources of saturated fat

• Dairy foods – such as butter, cream, ghee, regular-fat milk, and cheese

• Meat – such as fatty cuts of beef, pork, and lamb, processed meats like salami, sausages, and the skin on chicken.

• Lard

Plant-derived sources of saturated fat

• Palm oil

• Cooking margarine

• Coconut oil, milk, and cream.

• The American Heart Association recommends using plant oils rather than animal fats in food preparation to decrease saturated fat intake.

Is Coconut Oil a Good Choice?

• Coconut oil is highly saturated; nearly 90% of the fatty acids in coconut oil are saturated which is more than butter or beef fat

• If you like coconut oil, use it in moderation.

• coconut oil is a dense source of calories.

• adding coconut oil to your dietary pattern will quickly add extra fat and calories

Tips to Reduce Saturated Fat Intake

• Use lower-fat dairy products

• Swap butter for spreads made from canola oil, sunflower oil, olive oil, or dairy blends

• Cut the fat. Trim all visible fat from meat and avoid processed meat (sausage and salami)

• Choose healthier treats. Cakes, pastries, and biscuits are a major source of saturated fat in diets

• Read labels

Dietary Sources of Monounsaturated Fatty Acids

Monounsaturated Fatty Acid: (MUFA) are chemically classified as fatty acids containing a single double bond (in contrast to polyunsaturated fatty acids (PUFA) containing two or more double bonds and saturated fatty acids (SFA) without double bonds).

Health Effects of Monounsaturated Fatty Acids

• Decrease blood cholesterol

• Reduce your risk of heart disease and stroke

Follow the Mediterranean Diet to Increase Monounsaturated Fatty Acid Intake

Traditional diet features:

• Olive oil is the main fat

• Abundant fruits & vegetables, whole grains, beans, nuts, and seeds

• Daily intake of small amounts of cheese and yogurt

• Weekly fish intake; limited use of eggs and red meat

• Regular exercise and rest

• Moderate wine intake

Dietary Sources of Polyunsaturated Fatty Acids

Polyunsaturated fatty acids: fatty acids that contain more than one double bond in their backbone. This class includes many important compounds, such as essential fatty acids and those that give drying oils their characteristic property.

• Monounsaturated, saturated, and polyunsaturated fats all provide the same number of calories.

Omega-3 Fatty Acid Sources

Omega-3 Fatty Acid: an unsaturated fatty acid of a kind occurring chiefly in fish oils, with three double bonds at particular positions in the hydrocarbon chain.

• Primarily from nuts, seeds, fish oil (cold water fish: salmon, mackerel, lake trout, herring, sardines, albacore tuna), flax seed oil, chia seeds

• Also found in canola, walnuts, mussels, crab, shrimp, and soybean oil

• The recommended intake of approximately 2 servings of fish per week

• Fish and seafood are the best sources of omega-3 fatty acids

  Recommend eating at least two servings of fish a week. The highest levels of omega-3 fatty acids are in Mackerel, lake trout, herring, sardines, albacore tuna, salmon, and halibut; you should bake or grill the fish to avoid adding unhealthy fats.

  If you do not eat fish regularly make sure to include the following in your diet:

• Walnuts

• Chia seeds

• Flaxseeds

• Canola oil

• Soybean oil

• Flaxseed oil

Effects of Diet on LDL Levels

Increases LDL levels: saturated fatty acids

Decreases LDL levels: monounsaturated fatty acids, polyunsaturated fatty acids, omega 3 fatty acids, dietary soluble fiber

Dietary Recommendations for Prevention of CVD

• Total fat 20-35% of total calories

• Saturated fat < 7-10 % of total calories

• Polyunsaturated fat < 10% of total calories

• Emphasize Omega-3 Fatty Acids

• Monounsaturated fat < 20% of total calories

• Soluble fiber intake of 20-30g

• Reduce added sugar

• Keep body weight at a healthy level

• Increase physical activity

Keto Diet

• Developed in the 1920s

• Developed to treat children with epilepsy

• Now endorsed by celebrities, athletes

• Might see many success stories on social media (weight loss, blood sugar control)

• One of many low-carb diets, including Atkins diet, South Beach diet, Zone diet

• Gets its name because ketones are the source of energy that the body uses when it’s burning fat

• Ketones are produced in weight loss, regardless of the type of diet you are following.

• Anyone who is losing weight is actually on a keto diet

• Fatty acids travel to the liver, the liver uses them to create Ketones, Ketones are used as fuel

  Pros of the Keto Diet

• Can help you lose body fat. As the body’s main source of energy (carbohydrates) is missing

• Can benefit from a sedentary lifestyle. Less use of muscle glycogen

• Can reset insulin sensitivity. Making better use of glucose metabolism

  Cons of the Keto Diet:

• The diet is difficult to balance, and can easily lead to nutrient deficiencies

• The effects of maintaining ketosis for long periods are unknown

• Concerns: Impact on important gut microbes (starved of essential fiber)