What The Fat?!

“You shouldn’t eat that, it’s loaded with fat!”
“That’ll go right to your hips!”
“That’s gonna clog your arteries.”

“Really? Thanks for telling me, you may have just saved my life!”


If I had a dollar for every time I heard a conversation that went like this, I’d be a millionaire!  Contrary to popular belief, fats are not evil! They’re actually important to our health. Want to know the real scoop regarding dietary fat and why we shouldn’t swear by the “low fat,” “reduced fat, “no fat,” lifestyle? Keep reading. If not, carry on!

Fats are essential for human survival so it’s important for anyone who cares about their health or performance to have an understanding of how they affect us. The most important roles fat plays in our bodies include energy transfer and storage, and maintaining a healthy hormonal profile (think sex hormones and muscle building hormones).  So let’s dive into how fat plays a role in each of these functions and to talk about some general guidelines for how much, and what types of fat, you should be eating.

Fats serve as a primary energy source for the human body.

Fat is your body’s single most abundant resource for resynthesizing ATP, your energy currency. Fat is broken down inside our cells through a process known as Beta-Oxidation (BO). Because BO requires oxygen (aerobic metabolism), it’s a much slower process than the breakdown of other energy sources (carbs & protein), so fat serves as a primary fuel source for lower intensity, aerobic activities like sleeping, sitting, walking, eating, driving, hiking, etc.  Basically all low stress day-to-day activities. Fat is pretty much always being used to keep us moving and functioning throughout the day. Think of fat as a long, slow burning oil lamp versus burning newspaper. Which burns out quicker? Which one lasts longer?

Types of fats

There are many types of fats, but most of them can be categorized as either Saturated, Monounsaturated, or Polyunsaturated fat. Saturated fat is typically solid at room temperature. Think: cooled down steak, the pan after you cooked bacon, or coconut oil. Monounsaturated fat is typically solid at room temperature but starts to solidify at cooler temps. Plant-based oils are good examples of foods high in monounsaturated fat. Polyunsaturated fat is typically liquid at room temperature and includes your Omega-3s and -6s, fish, sunflower and avocado oil. Most foods that contain fat are combinations of these three types of fat in varying amounts.

Everyone loves avocados right?  More than 66% of avocado fat is monounsaturated, 12% is polyunsaturated, and 22% is saturated.

Generally speaking, a wholesome, balanced diet has equal amounts of these three types of fat making it important to have a variety of fat sources in you diet. For a list of other foods high in each of these types of fats see the image below.

Fats infograph article text.png

Are there any types of fats that I should avoid?

Funny you should ask!

Trans fats and hydrogenated/partially hydrogenated oils should be avoided or kept to a minimum. Food companies began using these types of fat to extend the shelf life of their products because they resist breakdown. But since their breakout into the food industry, they have been associated with increased risk of heart disease, obesity, and chronic inflammatory diseases. Trans fats have even recently been added to the list of banned foods by the FDA because of their correlation to chronic illness. Because of this, it’s rare that you’ll ever encounter trans fats, but hydrogenated and partially hydrogenated oils are still widely used, particularly in fast food and processed foods.

Don’t freak out! Moderation is key. It’s best to get the majority of your food from whole, minimally processed sources. The 80/20 rule is an excellent guide to follow when eating to optimize health and performance and minimize negative health outcomes.

Fats, Hormone Health and Cholesterol

Fats play a pivotal role in the production of certain hormones in our bodies called Steroid Hormones. Sex hormones, like testosterone and estrogen, as well as corticosteroids, like cortisol (the body’s stress hormone), are all steroid hormones that are affected by how much (or how little) fat we eat. Why?  Because these hormones are made from cholesterol and most foods that are high in fat are also high in cholesterol.

But wait, Isn’t cholesterol bad for us?

Well no, not necessarily.

Contrary to popular belief, cholesterol intake has very little to do with how clogged or how clear your arteries are. This is because of the roles the liver and genetics play in cholesterol regulation. When dietary intake of cholesterol goes up, the liver counteracts this by producing less of its own cholesterol. This ensures that cholesterol levels remain relatively constant, and eliminates much of the worry about eating too much cholesterol.

Now, if you have a known family history of genetically high cholesterol (these are people who have good diets, and healthy levels of body fat but still present with high blood levels of cholesterol and plaque build up in their arteries), you fall into a different category. So if your doc said to watch your fat/cholesterol intake, PLEASE listen to them!

Foods high in saturated fats are foods that also tend to be highest in cholesterol. For men especially, and people concerned with building muscle and increasing strength, it’s important to eat enough saturated fat to produce healthy levels of testosterone. This goes for women too!

It’s recommended that at least 30% of fat consumed be saturated fat, which fits right into what we discussed before about having an even mix of Saturated, Monounsaturated and Polyunsaturated fats in your daily diet.  If you’re not sure how much saturated fat you get on a regular basis it’s a good idea to track your food intake in an app like MyFitnessPal where you can see how much of each type of fat makes up your total daily intake. To figure out what 30% is for you, multiple your total daily intake by .3 for your Saturated fat goal.

What happens if I don’t eat enough fat?

Lot’s of thing!

Low fat diets (that’s less than 40 grams for women and less than 60 grams for men) can cause decreased testosterone and estrogen levels, low libido, slowed metabolic function, chronic fatigue, and in extreme cases a loss of mensease (this is fairly common in women’s athletics, especially gymnastics, dance, CrossFit and Bikini/Figure/Bodybuilding, and even powerlifting). These issues are more common for people eating in a calorie deficit because the less-than-sufficient calorie intake can alone cause a shift in hormone balance. The effects of a low fat/low calorie diet can be reverse but it does take some time. So be patient if you’re struggling with this and reach out to a nutrition coach who can help identify issues and refer you to the right doctor if you need one.

Well how much fat should I eat then?

Minimum absolute value for fat intake should be no lower than .3g/lb of bodyweight or roughly 20% of total calories for most people.

Example: You weight 160lb so 160 x .3 = 48 grams of fat

Example: You consume 2,000 kcal/day so 2,000 x .2 = 400 kcal.

Then divide this by 9 (because each fat gram is 9 calories) = 44 grams of fat

General guidelines to follow for strength trained men is minimum 50-60g per day, and for strength trained women a minimum of  35-45g. Remember, these numbers are recommended minimums and going above them is fine, and for most, important to ensure happy and healthy hormones.

What about athletes and competitors that rely on high carbohydrate diets to perform well?

For the most part, as long as fat intake doesn’t drop below the recommended numbers above and the person has a healthy body composition and relationship with food, then there is nothing to worry about. If you’re an athlete whose sport involves judgement based on being at an incredibly low (and potentially dangerous) body fat percentage, it’s a good idea to work with a nutrition coach who understands your sport and appropriate phases of dieting, maintenance, and reverse dieting. Prolonged periods of dieting can become dangerous if the conditions of a very low fat diet are kept up with for too long.

For almost all other athletes it becomes necessary to take a deeper look when negative health effects begin to arise. If there are adverse health effects taking place, or performance is decreasing, take a look at how much fat you’re eating. It could potentially be the answer to all your problems.

Maintaining optimal health and performance should be a universal goal, and while it easy to get caught up in the minutia of how much of “this” or “that” you should be eating, or what foods are “off limit,” it is important to keep the big picture in mind.

Eating a diet that is well balanced (80/20 rule), has lots of variety, and sticks to mostly whole foods (again with the 80/20!)  is a sure-fire way to maintain great health, body composition, and high performance.

Only when signs and symptoms of negative health effects arise is it necessary to look deeper and use the information provided to help determine whether or not something like fat intake is truly detracting from your health and performance.

For more articles just like this make sure to check out our Protein article here and be the first to know when our Carbohydrate articles are released by subscribing to our PRS Monthly Newsletter.

If you you feel you’d benefit from more individualized help with your diet you might like working with one of the PRS coaches through our Online Nutrition Coaching Program.