dietary fat: part 2

Now that we’ve talked a little bit about how to determine if the latest piece of nutrition advice is worth following, let’s talk specifics about dietary fats!

First, fat is a necessary part of everyone’s diet. The brain is largely made up of fats, fat soluble vitamins (A, D, E, and K) require fat to be absorbed properly, your body uses some fat for energy, and fat is used to make up cell membranes and hormones in your body, just to name a few things.

Here’s a breakdown of the different types of fats:

ScreenHunter_74 Sep. 23 15.51Saturated and trans fats are in red because they should be minimized, as they increase blood cholesterol levels and can be harmful to your health. Saturated fats should be kept to less than 10% of your total calories (less than 20 grams per day on a “typical” 2,000 calorie diet) or less than 7% of your total calories if you are at risk for heart disease. Trans fats should be avoided as much as possible.

Unsaturated fats should make up the majority of the fats in your diet and can be found in both poly- and monounsaturated forms. The often talked about omega-3s and omega-6s are long chain polyunsaturated fats and are considered essential because the human body can’t make these fats on their own – only plants can. Humans can, however, use some other shorter chain fatty acids from the diet to make the longer omega-3 and omega-6 fatty acids.

Omega-6s are in yellow because we already get plenty in our diets and having far more omega-6s than omega-3s in the diet can interfere with the process I mentioned above of converting shorter fatty acids into the longer omega-3s (like EPA and DHA) that are particularly beneficial to our health. Intake of omega-3 fatty acids is encouraged to help balance out the ratio between omega-6s and omega-3s.

So, which fats are provide more healthy unsaturated fats and which provide more unhealthy saturated fats? Let’s take a look at a comparison between different types of fats/oils and the amounts of each kind of fat they contain. The information in the graph is for 1 tablespoon of each kind of fat/oil.

ScreenHunter_74 Sep. 23 16.13

We can learn a lot from that graph up there! First, let’s consider the butter vs margarine debate. As you might be able to tell, only two items in that graph have a noticable amount of trans fat: butter and margarine. Many people think margarine is healthier because it doesn’t have as much saturated fat but, if we think back to the recommendations above, trans fat is considered far worse (elimintate) for heart health than saturated fat (<20 grams per day) and margarine has much more trans fat than butter. Either should be used in moderation, but I always use butter over margarine.

Palm kernel oil and other tropical oils (such as coconut oil) are notorious for their high saturated fat content, as you can see above. You may have never purchased palm kernel oil or seen it next to the olive oil at the grocery store but it is in I would say a majority of processed foods. You’re probably more familiar with coconut oil.

coconut oil[source]

While some research suggests that coconut oil may have beneficial effects on cholesterol levels due to the different way it is absorbed in the body, the results overall appear to be mixed. Without evidence of definite health benefits, I don’t recommend using coconut oil in place of other heart healthy oils. Regardless of its benefits, I wouldn’t use it more frequently than I would any other oil or fat. We know that olive oil is a heart healthy choice because of it’s high percentage of unsaturated fats, specifically monounsaturated fats. However, no one recommends going around and pouring olive oil onto everything you eat. When you need to use oil, olive oil is a good choice but it is still a concentrated source of calories (~120 calories per tablespoon) and should be used in moderation to leave room for other important nutrients in the diet. The same idea applies to coconut oil.

That’s probably more than you ever wanted to know about dietary fats! Monday will be part 3 – ways to actually add more good fats in and cut some of the bad fats out of your diet.




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