After the low-fat diet craze, which peaked in the 1980’s and has slowly waned ever since, many nutrition experts have been recommending “high” fat diets.
But the fat is always qualified as “healthy” fat.
Have you ever wondered what exactly is a healthy fat and what it can help you achieve?
Well, healthy fat is important for mental health, physical health, and fat loss.
Learn what the term healthy fat means and how you can use these fats to improve your life below.
What does Fat mean?
The first thing you need to know is that Fat is one of 3 nutrients called Macronutrients (meaning big nutrients). A nutrient can be defined as “A substance that provides nourishment essential for the maintenance of life and for growth.”
Protein and Carbohydrates are the other two. They are considered the big nutrients because they are the only nutrients that have calories (energy) that we can use to live on. You can only get calories from one other source, alcohol. Unfortunately alcohol is not considered a nutrient because it is not necessary and interferes with the body's ability for growth maintenance and repair. For this reason it is classified as a drug.(1)
Fat can be a confusing term in and of itself. This is because in food science we don’t use the technical definition of fat. When we say fat regarding your nutrition what we really mean is lipid.(2) Lipid is a more general term including both fats and oil. Fats are lipids that are solid at room temperature, such as butter. Oils are lipids that are liquid at room temperature, such as olive oil.(3) Room temperature means about 20° Celsius (68° Fahrenheit)(4).
But in short by Fat we mean lipid.
What does Healthy mean?
There are two relevant definitions of healthy for this conversation:
1: Indicating or promoting good health.
2: Normal, natural, and desirable.
The reason that both of these definitions are relevant is that normal, natural fats tend to promote good health.
How do Fats promote good health?
When most people think about Fat in their body they think excess body fat that they want to get rid of. But even that kind of body fat has some important functions such as keeping your body warm, protecting your organs, and serving as energy storage.
But what most people forget is that fat forms our cell membranes, forms our brains and nervous systems, helps transport the fat-soluble vitamins (A, D, E, and K) and helps make up hormones (5), including some of your major fat-burning hormones.
The fats that your body uses for all these functions come from your diet. If you have enough fat and enough high quality (healthy) fat your body can do these well.
Failing to get enough healthy fat makes it hard for your body to run efficiently.
What are Healthy (and Unhealthy) Fats
There are 3 main types of dietary fat: Saturated, Monounsaturated, and Polyunsaturated. The difference between them is their chemical structure.
The power of chemical structure is best demonstrated by this example. Diamonds and Coals are made of the exact same ingredient, carbon. But the structure of how that carbon is connected is very different, which makes for very different materials.(6)
Saturated Fat - Generally from animal fats and tropical oils
Monounsaturated - Common in olives, avocados, peanuts, groundnuts and tree nuts
Polyunsaturated - Common in flax, fish oil and most seed oils(7)
Then there is a fourth type, trans fat. Trans fat is found in small amounts in meat and milk fat. Otherwise it is almost non existent in nature. However, food processing can create trans fats in huge amounts.
Also, be on the lookout for “hydrogenated” in the ingredients list. This means trans fat. One of the tricks they use in processed food is that if there is less than half a gram of trans fat in a serving they are not required to list it under the numbers section of a food label. So manufacturers will intentionally make a serving small enough so that they aren’t required to put trans fat on the label. Once you eat two or three servings you have consumed a significant amount of trans fat.
When most people say healthy fat they mean monounsaturated or polyunsaturated. And when most people say unhealthy fat they mean saturated and trans fats.
But there is a large and growing body of research that even unsaturated fats from whole food sources have a large amount of healthy benefits for humans.
A whole food source is a one ingredient food. For example, tuna, almonds, avocado, beef.
Which are all great sources of fat. It is important to remember that you are not just what you eat, you are what your food eats. The fat in beef from an organic grass fed cow is going to be better for your health than a cow that was mistreated and had a poor diet.
For this reason when I say healthy fat I mean a relatively unprocessed fat from a whole food source.
The qualifiers are important because not all processes are bad. For example, Extra Virgin Olive Oil is technically a processed food product. But very few people will argue against its being one of the best health foods you can buy.
And unhealthy fats are the highly processed trans fats and hydrogenated oils.
How much Healthy Fat do you need in your diet?
Well, it depends. When we look at diet we want to look at the entire picture, not just one piece of information. For this reason there is a large acceptable range.
First, we will address a normal balanced diet. In this scenario the range is 20% to 40% of your calories coming from fat. To achieve this we start by aiming for about 30% of calories from fat.
Don’t worry…this doesn’t mean you have to break out the food scale and calculator. All you have to do is get 1-2 servings of a fat-dense food with most meals.
But this is just a starting point; some people function better with a little more, others with a little less, so we make adjustments to fit you as an individual.
What is a serving?
It is about the size of your entire thumb. Don’t get too caught up in being exact, just estimate and it will balance out over time.
The next step is to balance the saturated, monounsaturated, and polyunsaturated fat. We want to balance these out fairly equally so be sure to mix up your sources of fat. Here are some examples of each:
Saturated Fat - Animal fats (in eggs, dairy, meats, butter, cheeses, etc), coconut oil, palm oil
Monounsaturated - macadamias, pecans, almonds, cashews, pistachios, tahini, hazelnuts, olives, olive oil, peanuts, peanut butter, avocado, guacamole, canola oil
Polyunsaturated fats - fish oil, hemp seeds, algae oils, sunflower seeds, pumpkin seeds, soy nuts, walnuts, flax seeds, flax oil, chia seeds, brazil nuts
Second, there are the special cases of low carb and ketogenic diets. On these diets it is not uncommon for the fat levels to reach 50% - 90% of calories. Since you are eating fewer (or no) carbs on these diets, in order to get enough fuel and calories you have to make up the energy by consuming extra dietary fats.
There is some great research about using the ketogenic diet for certain medical conditions such as epilepsy, Alzheimer’s, ALS, autism, headaches, Parkinson’s, and sleep disorders.(8) For more information on this you should consult a doctor.
Recently a more popular use of the ketogenic diet has been weight loss. And while there is research that suggests that a ketogenic diet results in faster weight loss than just calorie restriction, people often gain the weight back when they quit it. Remember a weight loss diet is only as good as long as you can stay on it no matter how effective it is.
Like I always say, “Sustainability is Everything.”
In these cases you should still balance the types of fat and avoid unhealthy processed fats.
Healthy Fat has an important place in your diet. But we have a tendency to focus on the extremes.
Most people don’t need a very high fat diet, even though it is great for a few people.
Instead you should start with a reasonable amount and make adjustments until you find what is the best for you and your body.
2 Really we mean the lipid subtype triglyceride.
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7 It should be noted that Polyunsaturated omega 3 and omega 6 oils have different healthy benefits but that is beyond the scope of this article.