Dietary Fat: Friend or Foe?

The answer is twofold, inasmuch as the right amount of healthy fats are absolutely the body’s friend because it needs it to function normally and unhealthy fats are the body’s foe because they put it at risk for many chronic diseases and other negative health related issues.

Recently, the Harvard School of Public Health Update headline read “Forty years of low-fat diets have been a ‘failed experiment”, see link to article below.

The main point of the article was that it’s more important to consume healthy fats within normal limits rather than completely avoiding fat and, as has been done over the last few decades, replacing the removed fat with refined carbohydrates and additional sugar. This is because consuming excessive amounts of refined carbohydrates and sugars in our daily diet drastically raises the risk of obesity, cardiovascular disease, metabolic syndrome, type 2 diabetes, and much more.

Fat’s Primary Functions

Absorb and carry fat-soluble vitamins A, D, E, and K
Assist in the absorption of carotenoids
Serves as a source of stored energy, when needed
Assists in production of bile and hormones
Insulates organs
Regulates blood pressure, blood clotting, and lipids
Maintains healthy skin
Regulate the immune response
Provides insulation to stop heat loss

Fats Defined:

Fats are large molecules, known as lipids
Fats are made up of glycerol and fatty acids
Fat is one of the macronutrients in the human diet
Fat is 9 calories per gram, carbohydrate and protein each have 4 calories per gram
Dietary fat is the fat found in the foods humans consume

Fatty Acids:

Fatty acids (FAs) are long chains of carbon that have hydrogen molecules attached (bonded) to each carbon. If there are missing hydrogen molecules, the carbons then bond to each other to form a carbon double bond.

Triglycerides (TGs):

Comprised of one molecule of glycerol and three (tri) FAs
TGs are the main form of fat found in foods
When the body metabolizes (breaks down) dietary fat, fatty acids are separated out and used within the body to make or convert other things such as some polyunsaturated FAs

The many different types of FAs are separated into three groups, which are based on how many missing hydrogen molecules each FA has:

SFA - Saturated Fatty Acid

Increase risk of inflammation, cancer, heart disease, stroke, diabetes, and more
Raises unhealthy cholesterol (LDL)
Is not missing any hydrogen molecules, so fully saturated with hydrogen
Most are solid at room temperature e.g. bacon grease, butter
Exception, although fully saturated, palm oil, palm kernel oil, coco butter, and coconut oil are not solid at room temperature.
Food sources: meats, poultry with skin, whole and 2% milk products, butter, cream, full-fat cheese, lard, lamb, fatty (non-lean) beef, pork, and some tropical oils (see above)

MUFA - Monounsaturated Fatty Acid (Oleic Acid)

Increase good cholesterol (HDL) and vitamin E intake
Lower bad cholesterol (LDL), risk of heart disease, and stroke
Has one missing hydrogen causing one double carbon bond
Liquid at room temperature but solid or semi-solid when refrigerated e.g. olive oil
Food sources: olives, olive oil, many nuts, peanuts and peanut oil, avocados, many seeds, safflower oil, sesame oil

PUFA - Polyunsaturated Fatty Acid (Linoleic Acid)

Reduce bad cholesterol (LDL)
Lower risk of heart disease, stroke, and some cancers
Provide vitamin E
Provide omega-3 and omega-6 fatty acids
Has two or more missing hydrogens causing multiple double bonds
Liquid at room temperature and when refrigerated e.g. sesame or sunflower oil
Food sources: fatty fish, sunflower oil, soybean oil, corn oil, and sesame oil, walnuts, pecans, tofu, flaxseed, soybeans

EFA - Essential Fatty Acid

Polyunsaturated FAs known as Omega-6: Linoleic acid and Omega-3: Linolenic acid
Essential because the body cannot make them but requires them, so they must be eaten
Food sources: flaxseed, canola oil, soybean oil, flaxseed oil, walnuts, salmon, albacore tuna, mackerel, sardines, eggs labeled as higher omega-3 via feed or added

TFA - Trans Fatty Acid – (man-made TFA, not naturally occurring)

Created by food industry by adding hydrogen to all carbons to form fully saturated solid fats
Dangerous because TFAs lower healthy HDL cholesterol and raises unhealthy LDL cholesterol, which increases the risk for heart disease, stroke, and type 2 diabetes.
Buyer beware because, unfortunately, any serving of food that has 0.5 grams or less of TFA can, by FDA standards, be labeled as containing 0 grams of trans fat.
Read all food product ingredients lists to find the TFA identifying words of Hydrogenated or Partially-hydrogenated oils
Food sources: Mainly found in processed foods such as shortening, doughnuts, cakes, pie crusts, biscuits, frozen pizza, cookies, nondairy creamers, microwave popcorn, crackers, some stick margarines, some butter or margarine substitute spreads, many fried restaurant foods

Found at American Heart Association http://www.heart.org/idc/groups/heart-public/@wcm/@fc/documents/downloadable/ucm_469423.pdf

How Much Fat and What Types Do We Need?

The 2015-2020 Dietary Guidelines for Americans (DGA) does not promote following a low-fat diet but recommends the following:
Adults 19 years and older should consume 20-35% of their total daily calories from fat
Saturated fat, for both children and adults, should only make up 10% or less of total daily calories
To lower your health risks, use as many MUFAs and PUFAs as possible to make up your recommended daily fat intake rather than using saturated fat sources

Go to this link to calculate both your daily fat and saturated fat recommendations: http://www.mayoclinic.org/healthy-lifestyle/nutrition-and-healthy-eating/expert-answers/fat-grams/faq-20058496

TIPS FOR COOKING WITH FATS AND OILS