Dietary Fat : Truth vs. Fiction

Remember the food pyramid? Ever heard the FDA/AHA dietary recommendation on eating fat? They all advise us to eat less of it - more specifically, they say to protect your heart by avoiding saturated fat, and replacing fatty foods with whole grains. This idea has been broadcast so loudly that it has become common knowledge.

But is it correct?

As the data shows, when the FDA spoke, Americans listened. Between 1971 and 2000, the percentage of fat consumed by the average male American decreased from 40% to 30%. Surely that means that we should see improved health, right? Unfortunately, that has not been the case. The CDC data shows during this same time, obesity rates rose dramatically.

How could this be? Let’s look at a couple of common misconceptions about dietary fat:

Myth #1: Eating fat will make me fat

Makes sense right? It’s all fat, so common sense says that it will go directly into storage on your body.  Well, as is often the case, common sense is wrong. Dietary Fat will only be stored as body fat if you eat more calories each day than you expend. If you don't, then fat will be used as a source of energy. Low-fat diets have not been shown to be a good method for losing weight. This study from 2009 found no link between eating a low-fat diet and weight loss.

In fact, there are some fats that are processed quickly for energy that can help you burn body fat. We have already described the many benefits of coconut oil in detail in a previous post.

In addition, fat does not stimulate any insulin response. Insulin is a hormone that signals your body to start sucking up whatever glucose is in the bloodstream and store it in body fat. The main dietary trigger for an insulin response is the carbohydrate. This is also important because high insulin levels are associated with high body fat. Not surprising since Insulin also makes you hungrier and increases how much you enjoy sweet-tasting foods. It’s a vicious cycle:

Eating sweet foods --> Big insulin response --> Hungry and craving more sweet food

In fact, many people have lost a lot of weight using a ketogenic diet - a diet where you eat around 70% of calories from fat while limiting carbs to 5%. The most common result of this diet is often dramatic weight loss, followed by decreased hunger and a more stable mood.

Myth #2: Eating saturated fat will raise my cholesterol and clog my arteries

This is a myth that just won’t die. It’s hard to find a major article about nutrition that doesn’t throw in a comment about avoiding saturated fat. For a complete history of how this myth developed and was perpetuated, I recommend the book Good Calories, Bad Calories by Gary Taubes. The first section of that book is devoted to explaining the history of how we reached the point where we are today – that is, the rise of the low-fat diet.

In summary, there has never been a solid study to show that saturated fat is linked to heart disease. You may be shocked to hear this, since "everyone knows" the opposite. Over the years, multiple studies were started specifically to prove once and for all that such a link existed (just a formality, since everyone knew that saturated fats were bad) - but the results showed no link. In fact, the results showed no connection between saturated fat intake and cholesterol levels.

The proponents of the myth, led by Ancel Keys, came up with excuses for why the experiment failed instead of admitting they were wrong. They cherry-picked data that supported their claim and ignored the data that didn’t.  They wouldn’t back down - The official recommendation to avoid saturated fats (which still exists to this day, both from the FDA and AHA) was issued before the studies were even completed.  Yes, the #1 dietary recommendation from our government is based on bad science. Consider the 1992 Framingham Study, which also showed no link between eating saturated fat and blood cholesterol levels - here is a quote from the director of the study:

"In Framingham, Massachusetts, the more saturated fat one ate, the more cholesterol one ate, the more calories one ate, the lower people's serum cholesterol...we found that the people who ate the most cholesterol, ate the most saturated fat, ate the most calories weighed the least and were the most physically active." Dr William Castelli 1992 (Director of the Framingham study)

So Why Should I Eat Fat?

OK, so maybe fat isn’t so bad for us – but how can it help? Fats and cholesterol play important roles in our overall health.

Simply put, your body needs fat to function properly. Your brain tissue is composed of about 2/3 fat. Your nervous system is also mostly fat, as is every cell membrane in your body. Much of the fat in the brain is in the form of EPA/DHA, a type of Omega-3 fat. Omega-3 fats, along with Omega-6 fats, are fats that your body cannot make on its own - they must be consumed in your diet. Omega-3 fats are the most important, simply for the reason that the standard American diet contains very little of them.

Omega-6 is important too, but not really a concern because we typically eat too much of them. Overconsumption of Omega-6 EFAs can promote inflammation, which is at the root of many diseases. In western diets, the average Omega-6 to Omega-3 ratio is around 16:1. The optimal ratio is closer to 4:1. Studies have indicated many benefits of lowering this ratio, including a 70% decrease in overall mortality due to cardiovascular disease in people with a 4:1 ratio. So most of us would benefit from limiting Omega 6 fat consumption, in favor of eating more Omega-3 fats.

The benefits of Omega-3 fats have become fairly widespread - particular regarding overall heart health - but most people don't know that there are multiple types of Omega-3s, and they are not all the same. The Omega-3 you get from plant sources, such as flax oil or walnuts is alpha-linolenic acid (ALA). Many of the benefits of ALA appear to be attributed to the body's ability to convert ALA into EPA/DHA, the other types of Omega-3 fats.

 If you aren't a fish fan tilapia
is a mild option worth trying. 

EPA and DHA are readily found in fatty fish and seafood, and these are the most important types of fat you can eat. While your body can convert ALA into EPA/DHA, the process is highly inefficient in humans. Typically, only about 5% of ALA will be converted to EPA/DHA. The best direct source of EPA/DHA is seafood, but if you don't like to eat a lot of seafood, consider fish or krill oil supplementation. Smaller amounts of EPA, DHA, and ALA are also present in natural grass-fed beef, free-range chickens, and their eggs - but not in their grain-fed, farmed counterparts.



As mentioned above, EPA/DHA is important for your brain health, and consumption has been shown to be beneficial for treating ADHD, autism, depression, bipolar disorder, dyslexia, aggression, borderline personality disorder, and schizophrenia. Add in the decreases in overall mortality and inflammation, and it is easy to see how important these fats really are.

Would you want to miss out on the
 benefits of all this spinachy goodness?

Another interesting fact about fat is that it helps you absorb vitamins. Vitamins A, D, E, K are fat soluble. This means that they need fat to be properly absorbed by the body. In fact, a study from 2004 showed that people that used a fat-free salad dressing absorbed less of the vitamins from their salad.

So as you can see, the low-fat diet is not all its cracked up to be. In my opinion, the vilification of fat has had a profound negative effect on health in this country. Typically when you see a low-fat label on the front of a product, you can count on it having added sugar or artificial sweeteners, which have zero nutritional value and a load of negative qualities.

Now if you’ll excuse me, I’m going to go eat a grass-fed ribeye steak, covered in butter.