Dietary Fat is not the Enemy

Dietary fat is not the enemy. Despite this, dietary fat has been under attack from various organizations such as the USDA (US Department of Agriculture) and the ADA (American Diabetes Association). These influential organizations instead promote a diet low in fat and high in carbohydrates. So while these low-fat diets are fairly healthy, they do not produce optimum weight loss and help strengthen the false belief that ingested dietary fat directly becomes body fat. In this article, I hope to dispel this myth while showing the benefits and necessity of having some dietary fat.

First and foremost, I’m going to start of with a little science lesson. Chemically, dietary fats are generally triesters of glycerol and fatty acids. This means that the basic structure of most fats is three fatty acids attached to a molecule of glycerol. As far as saturated vs unsaturated fat, the difference is in their bonds between carbon molecules in their fatty acid chains (duh). Here’s a picture to make it a little easier to understand (it shows one of the fatty acid chains and not the whole molecule which is the same for both types):

While the difference is very small on the molecular level, the significance is great on the chemical and biological level. Because of this difference, saturated fat is solid at room temperature (butter), where as unsaturated fat stays in liquid form at room temperature (olive oil). Generally, experts tend to promote a diet fairly low in saturated fats with unsaturated fats composing the rest of one’s fat intake.

But really this issue of unsaturated vs saturated fats deserves a whole other article. The issue at hand is body fat vs dietary fat, and so now that you have a better understanding of dietary fat, I can discuss body fat. Scientifically, the correct name for what most people call fat is adipose tissue. This tissue is how your body stores excess lipids (fat), but this source of fat does not directly come from dietary fat you consume.

Rather, your body first metabolizes fat you eat (along with everything else) and utilizes it around the body. In fact, fat is essential to life, as some fatty acids are vital nutrients that the body cannot produce by itself. When you ingest dietary fat, it is circulated around your bloodstream as triglycerides. It can then be used throughout your body for various uses, including energy. If it doesn’t need to be used by your body, then it can be stored in adipose tissue. This storage process is greatly assisted by insulin, a hormone that is produced by your pancreas. Increased insulin leads to increased storage, and increased insulin is largely caused by ingestion of carbohydrates rather than fat. Therefore, while fats can be stored fairly directly, carbohydrates can actually be more of a problem as they increase insulin production. Without insulin and with few carbs, fat storage is actually fairly low, and this is the basis for low-carb diets. The reason why a high-carb low-fat diet works is because while insulin is high, there are few calories to store, but this diet can easily also be flipped to be high-fat and low-carb to have essentially the same effect. In fact, Alaskan Inuits (eskimos) ate a diet primarily composed of fat and protein and almost no carbs (basically no fruit or vegetables) and yet they were perfectly healthy and essentially never suffered from heart disease or cancer.

If you didn’t catch any of that, let me put it in more simpler terms. Fat is not the enemy because:

1. Some fatty acids cannot be produced by the body and must be obtained through food.
2. Dietary fat must first be metabolized by the body before it can be stored, and therefore dietary fat ≠ body fat.
3. Carbohydrates can actually be more problematic, as they promote insulin production which increases fat storage.
4. Certain native peoples such as the Inuit ate a diet full of fat and yet lived extremely healthy lives.