Blue pill or red pill? Is a calorie a calorie?

Is a calorie a calorie?

The two pills in the picture from The Matrix provide a great launchpad into a discussion on this topic.

So…Let’s see how deep the rabbit hole goes?

The standard nutrition dogma would have you believe that all calories are created equal. In addition, as long as we keep calories at a certain level we can lose (maintain) weight. But is the number of calories the important part of the story? What about the affect of those calories, how does each unit of energy behave once in the body?

Take our two pills, red and blue.  Imagine both undergoing some standard chemical tests to calculate their caloric content.  Both pills are utilized to the tune of 100 calories.  So we know they are isocaloric and theoretically add the same to energy balance.

Being the dutiful Americans we are, we take each pill as part of our daily diet, staying well below our 1800 calorie  daily limit.  However, once in the body the pills are very different.  The red (100 calorie) pill binds to intracellular machinery, decouples cells’ energy production mechanisms, and kills the cells (surprise…it’s cyanide).  The blue (100 calorie ) pill enters cells and is utilized for energy (fat).  The pills act similarly in calorimetry but have very different metabolic implications.

Why is it any different for food products?  Take a given amount of wheat and beef fat, 100 calories of each have a vastly different impacts on hormonal, metabolic, and epigenetic conditions in the body.  Who cares how they act in a chemical test.

I will touch on a few interesting affects the different types of calories (despite equal caloric amounts) may have once active in the body.

Satiety

Protein and fat can make you feel full longer.  Why? Ignoring the appetite stimulation affect of insulin in response to carbohydrate, satiety is mediated, in part, by the affect of cholecystokinin (CCK).  Secretion of CCK by the I-cells in the gut mucosa is stimulated by fat- or protein-rich food (not carbohydrate calories) entering the small intestine from the stomach.

CCK is thought to make you feel full in a few ways. First, it acts on the CCK1 receptor on the vagus nerve which slows the rate of stomach emptying.  More stuff to stretch your stomach lining equals fullness.  Second, CCK acts on the central nervous system by activating the orexin neurons in the hypothalamus.  When orexin neurons fire, they tell your brain that you have enough energy and can stop eating.  Interestingly, excess glucose (carbohydrate) inhibits the orexin neurons making you eat more.  I see why people binge on cookies, pop, and chips and not fatty steak.

Energy level

The CCK – orexin interaction can also explain the “zone-like” state that people get on a low carb diet.  CCK activates orexins which are important regulators of the sleep-wake cycle and energy.  When firing, orexin neurons make you alert, attentive, and active.  When inhibited, you feel sleepy and sluggish.  Remember, excess glucose is the inhibitor and protein/fat the activator.  People that follow low carb will relate to this having said goodbye to the “mid-morning drag” after giving up their morning cereal.  A protein/fat meal hones your energy level and hijacks the CCK-orexin system to ensure you have focus, energy, and a sharpness to your mental activity.

Hormone Response

The type of calories eaten can affect the hormonal environment in the body as well.  An interesting study from 1997 demonstrated the difference in testosterone levels in young men with differing amounts of dietary fat.  As you can see in the graph below, switching the calorie type had large implications on testosterone levels.  This could be from increased production or decreased sex hormone binding globulin.  Either way, I’m for more T.



This is just one example of how the type of calories can affect the body’s hormonal environment.  I’ve left the low-hanging fruit of insulin/glucagon balance and their affect on appetite to people who have done a better job than I could have.  Please comment if you would like my take on insulin, I’d be happy to oblige.

Inflammation

A paper entitled, “Glucose but Not Protein or Fat Load Amplifies the Cortisol Response to Psychosocial Stress” demonstrates how carbohydrate can facilitate an pro-inflammatory state through increased cortisol.   Excess cortisol is tied to chronic hyperglycemia, insulin resistance, decreased GLUT 4 expression (glucose shuttle), high blood pressure, decreased bone formation, decreased sleep, and an impaired immune system.  All around badness…

I’m a believer of some form of the “inflammation-hypothesis,” which holds a chronic inflammatory state responsible for many of the diseases of today including cardiovascular disease, cancer, and degenerative joint disease.

Conclusions

I’ve provided just some examples of why a calorie is a calorie…right up until it enters the body.  It is precisely because calories act differently in the body that I choose to focus on real, natural foods that are high in fat and protein.

Bacon wrapped turducken courtesy of Bacon Today

So go ahead, take the red pill…

Or, the story can end, you wake up in your bed and you believe whatever you want to believe.

Just be careful what that bed looks like.

Until next post…

Sources

Tsujino N et al “Orexin/Hypocretin: A Neuropeptide at the Interface of Sleep, Energy Homeostasis, and Reward System” 2009

Tsujino N et al “Cholecystokinin Activates Orexin/Hypocretin Neurons through the Cholecystokinin A Receptor” 2005

Volek et al “Testosterone and Cortisol in relationship to dietary nutrients and resistance exercise” 1997

Gonzalez-Bono et al “Glucose but Not Protein or Fat Load Amplifies the Cortisol Response to Psychosocial Stress” 2002