Wednesday, August 18, 2010

Carbohydrates are making us FAT

Now let's imagine you are stranded in the woods with a tent, a bow and arrow set, and a knife. You know you are so remote that it is best to try to survive till someone finds you. You now have to live off the land. Where would you get your next loaf of bread? Where would you get your next bag of chips? How about a candy bar? Would you die without these things? Cavemen survived and so would you.

Anyone know what a carbohydrate is? It is a macronutrient like fat and proteins. Unlike fats and proteins, carbohydrates are not necessary for the survival of humans. Let me say that in a different way for clarity and for effect. "Carbohydrates are not essential nutrients in humans: the body can obtain all its energy from protein and fats."

Just like the fact the saturated fat is not unhealthy , many are shocked to find out they do not need carbs to keep their energy levels up much less for survival. Foods that are heavy on carbs are breads, pastas, rice, pastries......well just about anything with grains and/or sugar. Fruits, vegetables, and milk contain carbs also but to a lesser extent.  By the way, over consumption of fruits and vegetables is not a problem here in the US. 

There are simple carbohydrates (sugars) and complex carbohydrates (starches). The difference between the two is the time it takes to get into the blood. What many do not understand is that all carbs get metabolised by the digestive tract and end up in the blood as glucose. Whole grain pasta or a tablespoon of sugar, either way they end up being glucose in the blood. Chronically high levels of blood glucose (blood sugar) have a degrading effect on the body. Stay tuned in future posts to hear about how chronically high blood sugar causes heart disease, diabetes, and cancer.

Lets talk about what happens when we ingest carbs. Simple and complex carbs will end up in the blood as glucose after the liver metabolizes the ingested carbohydrates.  The pancreas reacts to glucose in the blood by releasing insulin. Insulin facilitates the passage of glucose into the body's cells. Glucose goes to lean tissues first and when those are full, glucose is stored for later use in fat cells. When insulin is present in the blood, it blocks energy from being released from fat cells.  In a scenario of low and very low carbs in the diet, the body will be able to and actually will prefer to use the energy stored as fat because insulin levels will be low.

Have you ever heard of or experienced a "sugar crash"?  It is the tired feeling you get after eating a carb heavy meal.  Energy drink manufacturers and coffee houses love these because it is good for business. What happens in the body after a carb heavy meal is there is a big spike in blood glucose thus a high insulin response.  The insulin quickly gets all the glucose where it needs to be but because the insulin response was so great it remains in the blood for a while after it's job is done.  The body gets a feeling of tiredness because of the perception that the insulin is still there but it has no energy to put away.  These crashes lead to more carb cravings thus the viscous cycle of a carbohalic is continued. 

The problem with the Standard American Diet (SAD) is that there are a lot more carbs ingested than we need. We are not moving around enough to overcome the prescription of  about 1,100 calories per day of carbohydrates. The excess glucose is stored as fat. If insulin is raised in the blood, the body cannot use the energy in stored fat because the insulin blocks it from being released.

In summary, ingested carbs = raised insulin = stored fat. (Unless you are a highly competitive athlete expending a lot of energy)
Also, raised insulin = stored fat retention.


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