Fats often get a bad wrap. Ever since the low fat craze of the 80s people think fats are bad for us. We started eating lots of low fat foods but it didn’t make us as a country any healthier.
Even now when I ask some of my clients to add a few healthy fats to their diets, they get nervous…which I totally understand. There has been so much incorrect information out there for so long.
That’s why I want to show you why fats are important and which are beneficial or harmful. In a follow up post, I’ll show you how to incorporate fats as a part of a healthy diet.
Why do we need fats?
We need some fat in our diet because they:
- provide energy
- are part of cell membrane and nerve sheaths
- help absorb the fat-soluble vitamins A, D, E, and K
- are important for brain development and function (especially DHA an omega 3 fatty acid)
- provide the building blocks for our hormones
- play a role in our immune system response
- keep us feeling full and satiated
The Structure of Fats
To understand fats, we need to get into some science. Because really, what kind of nutritionist would be if I didn’t talk a little biochemistry?
I know, I know – I can see some of you rolling your eyes or just skipping to the next section (which is totally okay)…but if you can stick it out for a minute, it really is interesting (hopefully)!
Fats are made of fatty acids. These fatty acids consist of a carboxyl group (the left end of the pictures below) which is attached to a chain of carbon atoms with hydrogen atoms attached (the long row of C’s with the H’s attached in the pictures below).
Fatty Acids can be categorized in two ways:
- by how long the carbon chain is
- if they are “saturated” or “unsaturated” with the hydrogen atoms
Today I’m going to be talking mostly about saturated and unsaturated fats.
A saturated fatty acid will be “saturated” with hydrogen atoms which means each carbon will have hydrogen atoms surrounding it (as seen in the 1st picture above). Saturated fats also contain no double bonds (straight lines in 1st picture above) between the carbon atoms. Fats with a higher amount of saturated fatty acids are usually solid at room temperature.
An unsaturated fatty acid will contain at least one double bond (double line in 2nd picture above) so they are not saturated with hydrogen atoms. Fats with a higher amount of unsaturated fatty acids are usually liquid at room temperature and are referred to as oils.
- monounsaturated means the carbon chain contains 1 double bond
- polyunsaturated means the carbon chain contains more than 1 double bond
Okay, enough science for now! Thanks for sticking with me for those of you that read this part!
Fats: The Good
Healthy sources of fat include both monounsaturated fats and polyunsaturated fats.
Monounsaturated fatty acids (MUFAs)
Monounsaturated fatty acids (MUFAs) are found in greatest amounts in avocados, most nuts (almonds, cashews, macadamia), and olives/olive oil.
These fats are linked with lower cholesterol and heart disease as well as overall weight management.
Polyunsaturated fatty acids (PUFAs)
Polyunsaturated fatty acids (PUFAs) are found in greatest amounts in walnuts, pine nuts, most seeds (flax, sesame, sunflower, hemp and pumpkin), and for those who eat fish (salmon, mackerel, sardines).
Essential fatty acids are polyunsaturated fats which are called “essential” because they cannot be made by the human body. These fatty acids have special functions in the body such as: improving immunity, cell signaling, mood and brain health, heart health, and decreasing inflammation.
There are two types of essential fatty acids:
- Omega-3 fatty acids are found and in flax seeds and walnuts as well as some fatty fish. Omega 3s can help play a part in preventing heart disease and stroke. They reduce blood pressure, raise HDL (our “good cholesterol”), and lower triglycerides.
- Omega-6 fatty acids are found in flax seeds, hemp seeds, pumpkin and sunflower seeds, pine nuts, pistachios. Omega 6s have also been linked to reducing heart disease however, having too many Omega 6s compared to Omega 3s can cause problems (see the “In-Between” section below).
Fats: The Bad
Trans Fatty Acids
Trans fatty acids are the worst type of fat. They promote inflammation and have been associated with many diseases including heart disease, stroke, diabetes, and other chronic conditions.
Trans fats are created through a manufacturing process called hydrogenation, which changes the fat structure making it become solid or semi-solid at room temperature instead of liquid.
You might be wondering why anyone would want to make a liquid fat into a solid fat. Well it all comes down to money. Creating a solid fat increases the shelf life of the fat and makes it of value to the processed food industry, which incorporates it into many packaged foods.
Trans fats can be found in: cakes, pies, cookies, doughnuts, biscuits, crackers, margarine, fast food, french fries – pretty much most processed foods
The FDA has determined trans-fast are no longer “generally recognized as safe”. The best way to avoid trans fats is to minimize your consumption of processed foods.
Be sure to check the nutrition labels of foods for trans fats – new labels will list them. Be aware that any foods containing less than 0.5 grams of trans fats can be rounded down to zero and labelled “trans fat free” (even though it contains some trans fats). Also check the ingredient list. It will usually show trans fats as “partially hydrogenated oils”.
Fats: The In Between
Saturated Fat is one of those in-between fats. Saturated fats are found in the greatest amounts animal fats, butter, dairy, and ghee but for those of us on a plant-based diet, they’re found in tropical oils like coconut and palm as well.
Some research shows that eating a diet high in saturated fat can contribute to heart disease, however more recent research is saying that refined carbohydrates and sugars could be more of a problem for heart disease than saturated fat.
The 2015–2020 Dietary Guidelines for Americans recommends that healthy adults keep saturated fat to less than 10 percent of your calorie intake.
With a plant-based diet you do not have to worry too much about saturated fat in general. Most saturated fat you’d be getting would mostly likely be from coconut oil which would probably not be more than the 10% of your calorie intake.
Research also suggests that coconut consumption may not have any damaging effects on cardiovascular risk in healthy adults so I do not worry about using it sometimes.
Omega 6 to Omega 3 Ratio
The other “in-between” fat issue is one I briefly mentioned above in regards to the Omega 6 to Omega 3 ratio. An imbalance between the ratio of omega-6 to omega-3 fats could cause some issues.
Americans are over-consuming omega 6 fats (usually in the form of refined oil vegetable oils) which is creating a ratio as high as 20:1 (omega 6: omega 3), however, the optimal range should be from 1:1 to 4:1. This imbalance associated with increased inflammation and is linked to linked to many health conditions such as cancer, heart disease, diabetes, autoimmune disease.
To keep this ratio in check you can reduce your Omega 6 consumption by avoiding highly processed vegetable oils (like soybean, canola, corn, cottonseed, grape seed, safflower, sunflower), vegetable shortening, processed foods, and fast food while raising your Omega 3 intake by eating walnuts, flax seeds, chia seeds, hemp seeds (and fatty fish if you’re not fully plant-based).
Fun fact: hemp seeds have a perfect ratio of Omega 6 Omega 3 of approximately 3:1.
I’m going to follow up with a post on incorporating fats as a part of a healthy diet…but for now, here are a few recipes where I use some healthy fats:
- Walnut Meat Tacos – Omega 3s
- Cashew Cheese Sauce – monounsaturated fat, good Omega 6 : Omega 3 ratio
- Vegan Parmesan Cheese – monounsaturated fats
- Blueberry Chia Seed Jam – Omega 3s
- Avocado Toast – monounsaturated fat
- Mediterranean Quinoa Salad (using olive oil in dressing) – monounsaturated fat