A Beginner’s Guide To Fats
Originally I wanted to just do a quick beginner’s guide to cooking oils, but then I realized it really isn’t as simple as that. I’m not here to just tell you to “eat this, not that”. I’m here (hopefully) to teach you some things about nutrition that will help you make some positively healthy decisions for yourself.
So instead, this is going to end up the first of a number of posts about dietary fats, giving you some basic information before moving on to some specifics in later articles.
At the most basic level, fats are known as “fatty acids”, and when it comes to fatty acids you have saturated and unsaturated. Saturated fatty acids come mostly from animal sources (including dairy fats) and tropical plants (coconut oil). You can generally tell if a fat is saturated because it will be a solid at room temperature. Unsaturated fatty acids can be either mono-unsaturated (olive oil, most nut oils), or poly-unsaturated (fish oil, canola, safflower). Actually, one of the best illustrations about fats that I’ve found is from one of Alton Brown’s Good Eats episodes on frying. Go check it out… I’ll wait.
If you watched that video, there’s the part where Alton talks about shortening, and how it’s made by adding a hydrogen atom to the missing spot in an unsaturated oil. This basically takes an oil that’s liquid at room temperature and turns in to a solid. But in this case it’s not really a saturated fat, it becomes a trans fat.
Trans fats were developed as a way to take cheaper oils and make them more shelf stable and give them a better texture as a replacement for things like butter and lard and such. Originally they were supposed to be a healthier alternative to saturated fats, but it’s been pretty well documented now to just not be the case. Not only do trans fats seem to raise your LDL cholesterol (the “bad”), but they also seem to lower the “HDL” (the “good”) cholesterol levels. So personally, I would recommend avoiding trans fats whenever possible. The food industries have been coming up with alternative methods of making shortenings, margarines and such without trans fats, but I personally still tend avoid those products.
Other than the trans fats, fat in your diet is not evil. In fact it is an important source of energy. Fat is more energy dense than protein or carbohydrates and is important in the manufacture and balance of hormones, in the formation of our cell membranes, is needed in the transport of vitamins A, D, E and K and is essential in the formation of our brains and nervous systems. And on top of all that, fats just plain add good flavor, aroma and texture to foods.
Most dietary fat is in the form of tryglicerides – basically there’s three fatty acids joined together, and they can join together in any combination of saturated and unsaturated fats. This means that no food is 100% of any specific fat, it’s a blend of saturated, monounsaturated and polyunsaturated fats. Take a look at olive oil for example. It’s liquid at room temperature so while it doesn’t behave like a saturated fat, in reality it is 14% saturated fat, 78% monounsaturated and 8% polyunsaturated. That heavy percentage of monounsaturated fat, by the way, means that while it’s liquid at room temp if you put it in the fridge it will thicken up.
So just how much fat should you be getting in your diet? Well, according to the American Heart Association, most folks should do fine getting about 25-35% of their Calories in a day from fat. Now fats have 9 Calories per gram, just over twice that of proteins or carbohydrates, so you don’t need a lot to get what you need nutritionally speaking. If you’re on an “average” 2000 Calorie a day diet, that’s between 500 and 700 Calories a day from fats, or about 55-75 grams.
To put that in a bit of perspective, a teaspoon of butter has about 4g, a 1 ounce slice of cheese typically has about 7g, and a whole, large egg about 5g. So if you make an omelet using that butter, cheese and two eggs, that’s 21g, or about a third of your daily requirements right there.
Oh yea, anything with less than 5g of fat per serving is generally thought of as “low-fat”, but be careful. Adding a number of “low-fat” ingredients together doesn’t always make for a low-fat meal, and in the case of pre-packaged foods, well they often make up for the loss of flavor from fats by adding in sugars, so read the labels carefully!
If you have any questions or comments, feel free to leave them below – in upcoming articles I’ll be looking at the different types of fats a bit more in depth as well as going over the more prevalent cooking oils and their pros and cons.