Fat is Fuel, Not Foe (Part 1)

Every day we are bombarded by marketing hype expressing how low-fat, low-calorie diets are the way to a healthier, leaner life. We are told to eat vegetable oils because saturated fat leads to heart disease. We are told that fat makes us fat, so limit it as much as possible. Just look at the old food pyramid, with fats & oils lumped together with sweets as the most limited food sources. Even in the new pyramid, there is a focus on limiting fat, and a recommendation to use soy, corn or canola oil if you must. Even with all of this focus on healthy eating, America sinks deeper and deeper into a world of disease, obesity, and medication. Maybe it is time that we question some of these long-standing “truths” about our nutrition. Over the next few weeks, we will explore some of the most common myths surrounding fat, and what you can do to start making healthier choices when it comes to your dietary fat.

Myth #1: Fat makes you fat.

This myth is linked to another myth that I have talked about before: that calories are all that matter when talking about weight. It is commonly thought (and taught) that if you eat less and move more, you will lose weight. Because fat has 9 calories per gram, it is often advised to just cut the fat as it will be the easiest way to remove calories. Even more common is replacing fat with carbohydrates. Carbs only have 4 calories per gram, so now you can get the same quantity of food (in grams) but with half the calories! Hurray!

Unfortunately, not all calories are created equal. Your weight and fat storage is going to depend MUCH more on how your body responds hormonally to a given food than to the amount of food you ingest. This is not new information either, though now the mechanics behind it are better known. In 1956, a study came out showing that while caloric restriction could lead to weight loss, there were strange results when the macronutrients were manipulated.

http://www.scribd.com/doc/28131415/Kekwick-Pawan-1956-Lancet

The researchers found a number of intriguing results. First, during a comparison of 1000 calorie diets, each comprised of 90% fat, protein, or carb, the results showed a significant difference in weight change based on food emphasis. The group consuming 90% fat lost the most weight with protein close behind, while the carb group actually GAINED weight.

Not only this, the researchers also found that when comparing a 2000 calorie diet that was balanced in its macronutrients to a 2600 calorie diet that was high in fat and protein, the higher calorie group lost more weight!

While this is just one study, it was one of the first to compare diets from the perspective of calories and macronutrient breakdown. As our understanding of hormones and their influence on fat storage and weight control continue to develop, these findings become less shocking. One of the most important hormones in regards to fat loss is insulin. It is very difficult to lose fat or weight when we have chronically high levels of insulin. Insulin is released in response to an increase in blood sugar (insulin signals cells to store sugar, therefore decreasing sugar in the blood), so the more carb-dense your diet, the more insulin you will produce. This is the underlying cause of type 2 diabetes. When blood sugar levels are chronically high, your cells eventually resist the message from insulin to open up and take in sugar. When this starts, your blood sugar increases even more because it has nowhere to go, and insulin production increases even more! So now you have a rapid increase in blood sugar and insulin, which can lead to an increased rate of fat storage. The only way to reverse this process is to cut the sugar (carbs), and allow your blood sugar to stabilize. Coincidentally (or maybe not so), the best way to keep your blood sugar stable is to have more fat in the diet!

So it seems the fat actually makes you skinny. This is not to say that carbs are not important, but there has to be a balance. If you are struggling with fat loss, take a look at how much sugar/artificial sweetener/starch you have in your diet and see if that would be a good place to start.