Thursday, April 29, 2010

Carbs can Make you Fat? How does that Work?

A few people have asked me how it is that carbohydrates can cause weight gain, but eating fat doesn't tend to do so. The thing is, "calories in, calories out" is a myth. Unlike a car that simply burns gas, our bodies respond differently to different fuels. There are a few reasons that carbohydrates, more so than fat or protein, can cause weight gain:

It's easy to overeat carbohydrates.
Most carbs aren't very filling. Everyone who has ever eaten half a box of cereal, a bag of chips or box of cookies in one sitting, raise your hand. Ever eaten a stick of butter or a whole jar of mayonnaise at once? I didn't think so.

Carbs are addictive for some people. Dr. William Davis, a cardiologist, recommends a low-carb, wheat-free diet to all his patients. He reports that 30% of them go through wheat withdrawal.

Carbs can make you hungry. Eating carbohydrates raises your blood sugar, which causes your body to release insulin into the bloodstream. In some people, this is followed by a dip in blood sugar, which causes hunger.

Keep in mind, though, that eating too much of anything can cause weight gain.

Carbohydrates affect your insulin levels.
Again, eating carbohydrates causes your body to release insulin into the blood stream. This process is more complicated than simply overeating. Another blogger, Sami Paju, explains the process very well in his post "The How and Why of Weight Loss" on his blog, excerpted here. He also talks about diabetes and the physical differences between hunter-gatherers (the original low-carb people) and farmers (high-carb people).

This is what Drs. Michael and Mary Dan Eades say about insulin: "[It] regulates blood sugar... It controls the storage of fat, it directs the flow of amino acids, fatty acids, and carbohydrate to the tissues, it regulates the liver's synthesis of cholesterol, it functions as a growth hormone, it is involved in appetite control, it drives the kidneys to retain fluid, and much, much more." In other words, insulin is very likely the most important hormone when it comes to your metabolism.

As stated above, insulin controls nutrient storage and its main purpose is to get excess sugar, amino acids and fats out of the blood and into the cells. In the context of this article, the take-away message is that the higher your insulin levels, the more inclined your body is to store nutrients as fat. And notice, that I said "nutrients" instead of "fat". Our bodies will turn the excess protein and carbohydrate into fat. You can eat all the no-fat or low-fat food in the world and still accumulate body fat! On the other hand, lower insulin levels promote the usage of stored fat, leading to weight loss.

Read the rest here.

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