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.

FACT!

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.

Friday, August 27, 2010

Sleep more to weigh less

Sleep more to weigh less?

It’s amazing that something we spend ⅓ of our lives doing is something that doesn’t even get a second thought. Sleep gets no respect these days. Most people have decided that sleep is replaceable with a few cups of coffee in the morning and a 5-hour energy with lunch. It’s not that we don’t want to sleep, it's that our hectic lifestyles get in the way. Sleep is universally enjoyable, but for whatever reasons we aren’t doing enough of it.

Historically, humans slept in sync with the rising and falling of the sun. As a result, the human genome is not adapted to the erratic sleeping patterns that are shaped by our hectic lifestyles. Even those that make time to get sufficient sleep often have trouble falling or staying asleep due to multiv-variate problems such as poor sleep hygeine, chronic stress, anxiety, medications or sleep disorders such as obstructive sleep apnea.

When it comes to the actual act of sleeping the prescription is pretty straightforward; get 7-9 hours of sleep every night. Numerous scientific studies have found that the optimal range for sleep in adults is between 7-9 hours daily. When we deviate from this prescription on a regular basis the chances of morbidities are greatly increased.

The most prominent issue surrounding sleep today is sleep deprivation, not sleep excess. You don’t have to be a genius to realize that what the studies conclude about sleep restriction is true; we’ve all been there. Sleep restriction decreases performance; both cognitive and physical across broad performance domains. Worse, sleeping less than 7 hours is repeatedly linked to a suppressed immune system, obesity, high blood pressure, depression, suicide, metabolic syndrome and insulin resistance among other morbidities.

In addition to increasing chances of insulin resistance, sleep deprivation has been linked to increases in a hormone called ghrelin. Ghrelin stimulates hunger and specifically cravings for carbohydrates. As if this wasn't problematic enough, ghrelin decreases concentrations of the hormone leptin. Leptin antagonistically reduces hunger and carbohydrate cravings providing a feeling of satiety (no wonder why poor sleep is linked to obesity).

So what is the moral of the story? Focus on getting enough sleep. Adequate sleep will promote a more advantageous hormonal profile that will keep body fat low. And as always, avoid insulin resistance like the plague.