RBS FITNESS MYTH #5:

"Protein raises your metabolism the most"

I swear if you were to just take the advice of everyday people passing by, you would be hard pressed to believe that protein does just about everything, and we really don't need to eat anything else. Emotional overreactions are so commonplace in the fitness industry especially, that they have undoubtedly cemented many people's belief systems when it comes to nutrition. The path of least resistance in critical thinking is real, and If something is good for us then more must be better. And being that carbohydrates are bad according to most people and fats aren't discussed as much as they should be, the only genuine praise that can be awarded at this point is directed towards protein by default. But guess what? Even protein can become toxic if we override safeguards and attempt to eat to much of it. You'll get meat sweats and perhaps feel painfully full, experience nausea, some dehydration, and low energy in most cases so don't fret, since these are minor temporary issues that aren't even guaranteed.

This is my kind of meal. I would eat steak at every meal if I could and protein is my favorite macronutrient hands down, but it certainly has its limitations, contrary to popular belief.

Lets start with TEF (Thermic Effect of Food

TEF is a technical term for the amount of calories we burn from the food we eat. More specifically, it’s the amount of energy required to transport, digest, absorb, and utilize the food we eat in our body. You will also hear acronyms such as; DIT (Dietary Induced Thermogenesis) and SDA (Specific Dynamic Action) which mean the same thing. Scientists like to break down TEF into two components; The Regulatory and Obligatory Components. Knowing this information is not essential by any means, and I’m just disclosing it to be thorough. The Obligatory portion is the part involving the energy necessary for digestion, absorption, and metabolizing the food. The Regulatory is the part related to energy being lost as heat.

TEF is a relatively small number compared to the other components and we shouldn’t concern ourselves very much here because it makes up such a small portion of total energy burn. TEF sits around 10%. What’s important here is that you check off a couple things you or your clients should be doing to get the most out of TEF and then be done with it and focus more effort on the things that matter most, which I will cover here shortly. The two main things that affect TEF the most according to current research are how much lean mass you carry, as well as the composition or makeup of your meal. The more of each you have, the longer you will be processing the food and burning energy. But please keep in mind that this is a small number in the grand scheme of things. Here is a quick chart breakdown of the TEF for all sources of human energy:

Fat: 0–3% of calories consumed

Carbohydrates: 5–10% of calories consumed

Protein: 20–30% of calories consumed

Alcohol: 40% of calories consumed

One analysis reported that, while protein was the only significant determinant of the total TEF, every 1% increase in calories from protein was associated with a mere 0.22% increase in the total TEF. Based on these findings, if you were to double your protein intake from 15% to 30%, your daily TEF would increase by only 3.3%. So for each 2,000 kcal you consume (a number that might represent your total daily needs), you’d be spending an additional 66 kcal — a number easily offset by one small apple or a handful of potato chips. So as you can see it is very clear that eating protein directly will burn very little extra calories, and not contribute to fat and weight loss.

The indirect effects of TEF should be the focal point

However, research has shown that protein consumption can have indirect effects on food intake which is powerful information. The higher TEF from protein may in fact promote greater fullness so people don’t eat as much. One study in lean women found that greater 24-hour periods of TEF resulted in greater fullness and less food consumption.

Moreover, in order for the effect of more protein increasing fullness levels to take place, there has to be an intake of protein of at least 20%. I don’t think anyone has to really worry here. Lastly, eating protein may also promote satiety by increasing the rate of intestinal gluconeogenesis (IGNG) — the rate of glucose production within intestinal cells. Currently, only rodent studies exist to suggest that IGNG is a key signal to the brain with regard to energy homeostasis, but important enzymes involved in gluconeogenesis have been found in the small intestine of humans, suggesting that IGNG may also take place within us.

Finally, amino acids may promote satiety by directly affecting the brain. Specifically, they appear to activate mTOR and suppress AMPK within hypothalamic and arcuate nucleus neurons. The branched-chain amino acid (BCAA) leucine appears to be particularly satiating; and can reduce food intake when directly injected into the brains of rodents. 2

On a final note, when you look at the grand body of research, no macronutrient really deserves precedence over the other as they all work synergistically in the body to deliver energy and regulate various functions. As I mentioned earlier, being lean is going to be just as powerful and as the protein you eat in deriving calories burned from that consumed protein. So if you are carrying excess body fat or overweight worry about your total calories first and train correctly before you begin worrying about protein calories burned from TEF.

Protein can provide some energy

Creatine phosphate is definitely supported by protein production, with beef, fish, and poultry being the primary providers along with milk and cheese. However, the majority of energy needs for moderate to high intensity activity will come from fat, lactate, and glucose after initial creatine stores are depleted. Creatine also requires pretty substantial rest periods to restore, so this just isn't commonplace in most exercise situations, and the relative contribution of creatine compared to other energy substrates will be less and the creatine phase of metabolism will be much less from a collective time or duration standpoint more than anything. But it's still very important and necessary and couldn't be accomplished without the support of protein, so this is one stance that favors protein for metabolic influence, no doubt.

Protein provides building blocks to manufacture energy in the body

And yes, protein facilitates, supports, and provides key pieces to allow for greater energy production, but its very limited in providing energy (10% rule), and outside of just pure extra calories from protein it doesn't boost the metabolism much compared to carbs, fats, and calories. 1 This is where people get confused on the subject and are misinformed I've noticed. Bottomline is that protein does help provide energy but not in the sense that is popularly promoted in the media and across the web from what I continue to see. Protein and amino acids either help signal and deliver energy, and also act as a means of energy transportation to get the job done right. Examples include but are not limited too: NAD, NADH, and pretty much all metabolic protein-based hormones (i.e. Leptin and Adiponectin).

Lastly, amino acids can create powerful perceived cognitive effects, such as; better awareness, focus, and motivation (i.e. Tyrosine and increased dopamine production). What's tricky and where the confusion lies is that proteins mimic greater perceived but not actual energy levels through these verified mental effects.

SCIENTIFIC REFERENCES:

#1-Danforth, Elliot, et al. “Nutritionally-Induced Alterations in Thyroid Hormone Metabolism and Thermogenesis.” Experiential Supplementum

Effectors of Thermogenesis, 1978, pp. 213–217., doi:10.1007/978-3-0348-5559-4_25.

#2-Venuto T, Burn the Fat Feed the Muscle: Fitness Renaissance, 2005.