Friday, September 24, 2010

Carbohydrates, Physiology & Body Fat

We need to take a step back and understand what is going on in our bodies and how simple food and lifestyle choices can affect our physiology. Today we are going to talk about over consumption of carbohydrates and some of the physiological changes that take place when one consumes an excess of these addictive goodies. Disclaimer: It is not your fault that you enjoy carbohydrates and processed food. We are hardwired to crave and seek out fatty, salty and sweet (think Snickers).

It's important to understand that no matter how "complex" the carbohydrate is that it's inevitably reduced to simple sugars (glucose or fructose) in the body. So those "nutritious" whole grains are quickly reduced to sugar in the body. Once ingested, carbohydrates can be assimilated three different ways. If we are in a hypocaloric (underfed/fasted) state carbs will be used for energy and burnt immediately by the bodies glucose loving tissues. The second fate of carbs involve its storage in the liver as a starch called glycogen. The liver reorganizes the glucose and fructose molecules into glycogen which can be stored in the liver and in the muscles.

The third fate of carbohydrate occurs when both the liver and the muscle stores are "topped off" with glycogen. When the liver and muscles can no longer handle any more glucose, our body does what is best for it and removes the necessary amount of glucose from the blood via the liver converting it to palmitic acid. PA is then stuck to a glycerol molecule and becomes a trigyceride. The triglyceride is packaged with proteins and cholesterol as a VLDL ((very low density lipoprotein (a bad cholesterol)) which is sent into circulation.

Once in circulation these VLDL's are either used as fuel (unlikely in the presence of glucose) or stored on the part of your body that knows how to store fat best. VLDL's also interact with the brain. Palmitic acid profoundly effects metabolism by decreasing our sensitivity to leptin. This begins a process where our leptin sensitivity is degraded. If one loses their leptin sensitivity (becomes leptin resistant) they lose their ability to control their appetite. They no longer receive the message that we are full and consequently the havoc of their "sweet tooth" is soon to ensue. Remember, carbs are ADDICTIVE and we are innately hardwired to consume them.

The now carboholic who has lost their ability to sense leptin and thus has poor appetite control will do what we are hardwired to do eat fatty, salty and sweet foods. Since we devotedly follow the USDA food guide pyramid and make sure we get our grains, we can guarantee an over abundance of the nutrient that got us into this overeating hypercaloric state in the first place, CARBS.

So what is the solution? In short, a more balanced diet higher in protein and healthy fats. Less lipophobia will result in less carbohydrates and subsequently slimmer waistlines and a healther nation.


Grains are not essential. Carbohydrates are the one nutrient that we don't need to survive. Protein and fat we cannot live without.

Wolf, Robb. (THE PALEO SOLUTION) THE ORIGINAL HUMAN DIET BY Wolf, Robb(Author)Hardcover{The Paleo Solution: The Original Human Diet}. unknown: Victory Belt Publishing, 2010. Print.

Rolfes, Sharon Rady, and Eleanor Noss Whitney.Understanding Nutrition. 12 ed. Belmont, CA: Wadsworth Publishing, 2010. Print.


  1. Good post, although it could be debated whether carbohydrates cause insulin and leptin resistance alone (from a dietary perspective). A good example that could counter that argument is the fact that certain indigenous cultures obtain more than half of their calories from starchy carbohydrates (mostly tubers) and sugars (fruits) and exhibit no signs of insulin resistance and remain generally free of western diseases. Their activity levels aren't much higher than the average American either, so a high activity level can't explain their lack of metabolic syndrome.The more likely reason for carbs effect on insulin and leptin can be attributed to lectins binding to insulin and leptin receptors sites, causing resistance. While I agree with your points I think they're more applicable in the context of processed foods and non-paleo carbs rather than generalizing it to all carbs, although you did mention grains specifically. All-in-all, good stuff.

  2. Excellent thoughts Greg. We'll have to address Lectin at some point too. Didn't you do a project on it for Immaculata? Anyway, quick read up on Lectins.