Don’t worry. For the sake of this post, we’re just going to use the word “fat” when we refer to lipids. Lipids are just the overarching macronutrient category whereas fat is a type of lipid along with oils. For example, peanut butter is a fat whereas oil-at room temperature-is an oil. Both fats and oils are lipids.
We’re just going to use “fat” instead of lipids. Just know that difference I mentioned above and we will all be okay (and not fat).
Thankfully, the stigma surrounding fat is slowly but surely beginning to die down. Before, fat was the bad guy, and people were trying everything they could to reduce their fat intake. That’s why now we have so many low-fat options. FUN FACT.
Coming in at a hefty 9 calories per gram, fat is a dense substance that can accumulate calories quickly if not monitored closely. Take a serving size (tablespoon) of oil. It’s usually 14 grams of fat per tbsp. That’s 126 calories from a very small (and not filling) food. Now, this does not make fat bad or unhealthy. What else are you going to cook with? Water? Nononononono. Oil and butter make things tasty. Just watch how much you lather on your food if you’re watching calories or trying to lose weight.
Contrary to popular belief, fats play a host of important functions for our bodies. From fueling activity to improving brain function, fats are essential so don’t miss out on this lovely macronutrient.
Fat can be a source of energy when you’re at rest or performing light activity. When resting/relaxing, we are able to take in oxygen and don’t need to rely on carbs’ quick utilization since we aren’t doing any crazy activity that demands energy at that moment. This lack of activity, along with the availability of oxygen, allows us to use fat for energy.
When we are doing aerobic exercise such as running, fat is the preferred source of energy because we are able to utilize the oxygen we take in from breathing. During anaerobic exercise like intense lifting, there is not enough oxygen being taken in to utilize fat initially. As a result, carbohydrates are used for more intense activity since they don’t require oxygen to be metabolized.
While we all hate that we can store an unlimited amount of body fat, it is useful for us to have this evolutionary adaptation in times of famine or food insecurity (low availability of quality, nutritious foods). In times such as these, our body fat stores will become what we survive off of. The issue arises when we have more food than we can eat being shoved in our faces on a daily basis (cue the generic bald eagle screech and picture in your mind ‘Murica).
Another (better) function of fat is that it allows certain vitamins to be transported and absorbed by the body. There are two types of vitamins, water-soluble and fat-soluble. Water-soluble vitamins can be transported and absorbed simply by water whereas fat-soluble vitamins require fats that transport the nutrients through the gut and blood to the body’s cells. The fat-soluble vitamins are A, D, E, and K. You can find these vitamins in vegetables and dairy products. It would help to consume some sort of fat with these foods for absorption. Luckily, dairy naturally contains fats already, but vegetables can be cooked with oil or dipped in peanut butter to improve absorption, just to name a few ideas.
Lastly, fats improve the health and ability of cells. Fats allow the membranes of our cells to be flexible. This allows cells to move and slide around one another when necessary such as red blood cells moving through capillaries. Fats are also in the brain as a substance called myelin. Myelin helps our brains function at the high rate that it does by improving the speed of signals being sent to and from the central nervous system.
Keep in mind, these are just a few of the purposes of fat. There are many more but these are some of the primary roles.
What Are Fats Made Of?
There are multiple forms of fats that we consume, but the majority comes from what are called triglycerides, so I will focus on those, but know that there are also phospholipids and sterols (think cholesterol).
At a basic level, fats are a combination of two substances, fatty acids and a glycerol backbone. I won’t go into detail, but fatty acids consist of chains of carbon and hydrogen compounds. At one end, the fatty acid attaches to the glycerol backbone by connecting to one of glycerol’s three carbon atoms. It almost looks like a jellyfish!
Anyway, fats change in their nature by having different lengths of fatty acids, the way carbon and hydrogens bond, and the number of hydrogens bonded to carbons. This is how we get unsaturated, saturated, and trans fats, among others.
HERES’ A FOOD INDUSTRY SECRET FER’ YA’!
The FDA requires food companies to label the amount of trans fats in their food per serving if the amount of trans fat per serving is greater than or equal to 0.5mg; however, if the content is less than that, even 0.499mg, they do not have to label it. Also, food companies can manipulate the serving size to where it does not show any trans fat. So the food nutrition facts may not always tell the complete story.
Wow that sucks. So how do I know if food has trans fat in it?
Great question! It’s very simple. Look at the ingredients panel on the nutrition label and search for “partially hydrogenated oil”. Hydrogenation is the process that creates trans fat. Unfortunately, you can’t tell how much is in the food, but this is a way to tell if their is any trans fat in the food. You won’t die if you consume some, but it’s a good idea to try to reduce or limit your intake of trans fat because it has been shown to increase cholesterol levels which can lead to cardiovascular disease¹.
How Much Of My Diet Should Come From Fat?
Another fantastic question! Let me start this section off by saying FAT IS ESSENTIAL. Don’t miss out on it because your body needs it. Now, of the three macronutrients, fat is required in the lowest quantity. According to the Accepted Macronutrient Distribution Range (AMDR), roughly 20-35% of your total calories should be from fats. This should allow for proper brain functioning and provide energy to help you go about your day.
But not all fats are created equal of course! Work to obtain most of your fats from unsaturated sources such as vegetable and canola oils, nuts and nut butters, seeds, avocados, and eggs. It is completely fine to get some saturated fats in your diet, but try to keep it around 10% of your total calories. There are plenty of foods that contain saturated fats along with many other vitamins and minerals (think meat, eggs, milk, etc.).
I hope by now you know that fats are not unhealthy or will make you fat. I know you’re smarter than that! So go ahead and get some fats in! Comment below any questions you have about fats! Thanks for reading!
1The Science of Nutrition by Janice Thompson, Melinda Moore, Linda Vaughn