Fat is another of our macronutrients that is often in the centre of much debate, much like carbs. Is it good for you? Bad for you? Have a look at what it actually is and how it appears in our diet.
What is fat?
Fats are organic molecules made up of carbon and hydrogen elements joined together in long chains called hydrocarbons. These molecules can be constructed in different ways, which creates different types and their unique properties. The molecular configuration also determines whether fats will be healthy or unhealthy.
There are three main types of dietary fat: saturated, monounsaturated, and polyunsaturated.
Saturated – Animal and tropical oils (Ex. coconut, palm)
Monounsaturated – Olive oil, avocados, peanuts, groundnuts and tree nuts
Polyunsaturated – Omega-3, flax, fish oil, omega-6, most seed oils (e.g. canola, safflower, sunflower)
The difference between saturated and unsaturated lies in the bond structure.
Saturated contain no double bonds. Each carbon (C) has two hydrogens (H). The chain is saturated with hydrogens. Because of this chemical configuration, saturated fats are generally solid at room temperature.
Unsaturated fats, on the other hand, have one or more double bonds between the carbons. Thus not all of the carbons have hydrogens stuck to them. This puts a kink in the chain.
Monounsaturated fats have one double bond and polyunsaturated fats have more than one.
These molecular shapes of various fats are important, because the shapes determine how the various fats act in the body.
What is a healthy fat?
In popular terminology, the monounsaturated and polyunsaturated fats are what most people refer to as healthy.
Yet humans have likely consumed unprocessed forms of saturated fats (such as organ meats from wild game, blubber from seals and whales, milk, or coconuts) for their entire existence. Humans evolved on diets consisting of marine life, wild game and/or inland plants, which provided abundant omega-3 and other unprocessed fats. Early humans (and many hunter-gatherer groups today) consumed all parts of animals – including fatty tissues such as blubber, organs, and brains along with eggs from fish, fowl, and reptiles.
A better definition of healthy fat might be relatively unprocessed fats from whole foods.
Unhealthy fats are typically those that are industrially produced and designed to be nonperishable, such as:
- Trans-fatty acids: appear in processed foods
- Hydrogenated fats: such as margarine (hydrogen is added to the fat chain to make a normally liquid and perishable fat into a solid and shelf-stable fat)
- Most shelf-stable cooking oils: safflower, canola, corn oil, etc.
In Balance: Since humans evolved by eating a diet of whole foods, fat intake from mono-, poly-, and saturated fat was evenly distributed.
Why are healthy fats so important?
People are often concerned about excess dietary fat, but not getting enough good fats may also cause health problems.
We need adequate fat to support metabolism, cell signalling, the health of various body tissues, immunity, hormone production, and the absorption of many nutrients (such as vitamins A and D). Having enough fat will also help keep you feeling full between meals.
Healthy fats have been shown to:
- Protect cardiovascular system (though there is less evidence for protecting against heart failure)
- Improve body composition
- Alleviate depression
- Prevent cancers
- Preserve memory
- Preserve eye health
- Reduce incidence of aggressive behaviour
- Reduce ADHD and ADD symptoms
Fat we consume is digested and either used for energy, stored in adipose tissue, or incorporated into other body tissues and organs.
Many of our body tissues are lipid based, including our brains and the fatty sheath that insulates our nervous systems. Our cell membranes are made of phospholipids, which mean they are fat-based too. The fat we consume literally becomes part of our cells. It can powerfully influence how our cells communicate and interact. For this reason, balancing our fat intake can promote optimal functioning of our entire body. Therefore it is important that we emphasize whole food fat sources in our diets, and supplement as necessary.
What to do:
Get a mix of fats from whole, unprocessed, high-quality foods. These include nuts, seeds (hemp, flax, and chia are especially nutritious), fish, seaweed, pasture-raised/grass-fed animals/eggs, olives, avocado, coconut, and cacao nibs.
Avoid industrially processed, artificially created, and factory farmed foods, which contain unhealthy fats.
Keep it simple. Do not worry too much about exact percentages and grams.
If you are: taking blood thinners; have heart rhythm disturbances; are scheduled for surgery in the immediate future; and/or have any bleeding disorders then check with your doctor and/or pharmacist before supplementing with additional omega-3s.
References: (R. Andrews, PN, All About Fats)