Just in case you haven’t heard (though I’m sure you have), DIETARY FAT DOESN’T MAKE YOU FAT. In fact, we need healthy fats in our diet for our systems to function properly. Fats help our bodies to support the growth of body tissues (including those that protect our brain and nervous system), aid in hormone production, and help our immune system. Our cell membranes are fat-based, so changes in fat composition can affect the way that our cells communicate. There’s also strong evidence that an adequate level of dietary fat can help us feel more full after eating, which in turn helps us stick to our nutritional plans.
“The idea that all fat is bad for you, the exclusive focus on adverse effects of fat may have contributed to the obesity epidemic…The emphasis on total fat reduction has been a serious distraction in efforts to control obesity and improve health in general.” – Walter Willett, Chair of the Department of Nutrition at the Harvard School of Public Health
Got it, so I should start cooking with more butter?
Not exactly. Let’s take a look at the different types of fat in our diets, where they come from, and what they do.
All Fatty Acids (FA) are made of long chains of hydrogen and carbon atoms. The various classifications of fat come from the shape of their bond structure. Keeping in mind that most whole foods contain a mix of fatty acid types, let’s delve a little deeper into the fats that occur in nature.
Saturated Fats (SFA)
Saturated fats usually come from animal products, and are solid at room temperature (think butter, lard, cheese, milk, etc.). Coconut and palm oil are also saturated fats. For years, saturated fats got a bad rap for their impact on cardiac health. More recent studies show that a balance of saturated and unsaturated fat in the diet can actually positive effects on cardiac function and cholesterol. The key is in moderation – aim for only one third of your dietary fats to be saturated.
Saturated fats have no double bonds, each carbon has 2 hydrogen molecules. They lay flat, allowing them to pack more tightly into cell membranes. Unlike saturated fats, virtually all naturally occurring Unsaturated Fats have a double carbon bond that gives their chain a kink. The kink allows the chain to fold onto itself, and takes up more space within your cell membrane. When fats pack too tightly into cell membranes, your LDL rises, and your cells become less fluid, making it more difficult for them to receive messages from neurotransmitters. This is how saturated fat got its bad reputation. Again, this doesn’t mean you should avoid saturated altogether, just keep them to a third of your fat intake.
There are fats that don’t come from animal products?
Lots of em’! Knowing where you can find alternative fat sources is the first step in balancing your dietary fat intake.
Monounsaturated Fats (MUFA)
Monounsaturated fats come from seeds and seed oils (hemp, flax, chia seeds are great places to start), nuts and nut oils, olives and olive oil, and avocados and avocado oil. Studies show that MUFAs appear to lower LDL (bad cholesterol). Many of us don’t get enough of these in our daily intake, so load up, but keep in mind that fats are more calorically dense (9 cal/g) than protein and carbs (4 cal/g), so your portioning of fats should be smaller.
Polyunsaturated Fats (PUFA)
Most other oils are Polyunsaturated fats. We can break PUFAs into 2 categories;
Omega-6 PUFAs and Omega-3 PUFAs. Omega-6s are found in plant oils, like vegetable, corn, and soy oils, and Omega-3s are found in marine oils, like fish and krill oils. An ideal balance of Omega 3 to Omega 6 is 1:1, however most North American diets are more like 1:20, since Omega-6 abounds in the vegetable-based oils we use for cooking, and in factory-farmed animals who are fed corn and soy diets.
Polyunsaturated Omega-3s are important in our diet to help support nervous functioning, help our brain develop, and boost our immunity. They also have modest anti-inflammatory properties. The essential fatty acids in Omega 3s are:
DHA – docosahexaenoic acid and EPA – eicosapentaenoic acid, both found in marine oils
ALA – alpha-linolenic acid, found in flax, walnuts, chia, and hemp oils
Since it’s tough to get a decent balance of Omega-3 to 6 in our current dietary climate, many people supplement with daily fish oil. Alternatively, you could just start eating more mammal brains and eyes, since they are incredibly rich in DHA and other Omega-3s – way to make healthy choices, zombies!
Fats are awesome, I’m going to eat them all!
Slow down there, cowboy. There are some fats you’ll want to be avoiding:
Trans Fats (Hydrogenated Fats, Partially-Hydrogenated Fats) are made by blasting unsaturated fats with hydrogen (hence “hydrogenated oils”). This improves shelf life, and gives the fats a smoother mouth-feel – the more hydrogenated the smoother the taste. Unlike naturally-occurring unsaturated fats, trans fats don’t fold, they lay flat like saturated fats, and can cram tightly into cell membranes, causing all sorts of problems. What’s worse is that they are even less metabolically active than saturated fats, so they stay in the bloodstream longer and are more likely to clog arteries or be stored as body fat. And if that wasn’t damning enough, the essential fatty acids that occur naturally before hydrogenation are destroyed in the process, so you’re actually getting rid of good fats in your diet and replacing them with smoother-tasting nutritionally-devoid gunk.
I am now a dietary fat genius. How can I start incorporating my new knowledge?
You’re in luck! In our next post, Booty and I will give you some dietary fat-boosting strategies, and some tasty recipes to try.