The Law of Metabolic Efficiency1/31/20
Efficiency is defined in the world of engineering as:
“The ratio of the useful work performed by a machine or in a process to the total energy expended or heat taken in.”
If a machine operated at 100% efficiency, it would produce an amount of useful work equal to how much energy was put into the system.
Unfortunately, no machine is 100% efficient, including the most sophisticated machine ever created -- the human body.
Every system (or machine) suffers inefficiencies, which can be thought of as wasted energy or a “sunk cost.”
You’ve lived inefficiency yourself we all have.
Take a look at a typical day at the office.
Do you sit down and continuously bang out assignments and “to-do’s” the full 8 or 9 hours that you are at the office?
Not a chance.
As we said, no machine, even the most dedicated workers, are 100% efficient.
The same holds true for your metabolism.
The more efficient metabolism an individual has the greater number of calories they extract from the foods they eat, and store them more readily, dissipating less of it to heat (thermogenesis).
On the flip side, a less efficient metabolism does not extract calories efficiently, which means it expends (“loses”) more of them as heat.
There a number of factors that contribute to how efficient (or inefficient) your metabolism is, including age, sex, amount of muscle mass, genetics, hormones, training, and food choices.
Do I Want an Efficient Metabolism?
If weight loss is your goal, then you want an inefficient metabolism whereby your body is expending more calories than it’s deriving from food.
This places your body in a negative energy balance (calorie deficit) which is the main principle that drives weight loss.
An individual with a more efficient metabolism will derive a greater proportion of energy from the food they eat and then store it, while an individual with a less efficient metabolism “loses” more of that ingested energy (food) to thermogenesis.
Now, here’s the “catch.”
Dieting makes your metabolism more efficient.
The technical term for this is “adaptive thermogenesis is doing.”
Essentially, the body senses that it is in an energy deficit, and adapts by downregulating (lowering) the amount of calories you burn through a combination of decreasing your resting metabolic rate as well as your non-exercise activity thermogenesis (NEAT).
In other words, prolonged dieting forces your body to burn fewer calories at rest, and it also starts to do less activity overall (tapping your fingers, fidgeting, walking from one room to another, etc.).
Rather irritating, we concede, but it’s not really your body’s fault.
Remember, the human body is an advanced machine. As such, it comes equipped with numerous “countermeasures” it can enact at a moment’s notice to ensure survival.
When faced with a prolonged calorie deficit, the body compensates by downregulating how much energy it expends each day, so that it doesn’t need as many calories to survive.
Fortunately, there are a few things you can do to counteract adaptive thermogenesis, and it all starts with your diet.
Metabolic Efficiency Diet
You’ve likely heard that “a calorie is a calorie”, and while there is some truth to that, it’s not 100% true.
For instance, certain macronutrients (protein) cause you to feel more full than others (carbohydrate).
Moreover, certain macronutrients (protein, again) force your body to work harder to digest than others (carbohydrate and fat).
What this means is that if you’re trying to make your metabolism more inefficient (work harder while getting “less), you want to eat foods that force your body to burn more calories to digest.
This means that you want to make protein the foundation of your diet.
Protein is the most “expensive” macronutrient for your body to digest, meaning it requires the most energy (calories) to breakdown. And, protein is the most satiating macronutrient, which means it helps you feel fuller than either carbs or fat.
Moreover, due to the intricacies of human physiology, protein is also the hardest macronutrient for your body to store as fat. The reason for this is that in order to be stored as fat, your body first has to breakdown protein into individual amino acids (which requires energy).
Then, if your body doesn’t immediately need those amino acids, it will convert them to glucose (which requires more energy).
Finally, if the body has no immediate need for glucose to either fuel activity or replenish muscle glycogen, the amino acids turned carbs will then be converted to fatty acids, which requires more energy again.
The takeaway here is that protein is very taxing for the body to metabolize and if there was one macronutrient you would overeat on, it should be protein.
After protein, carbohydrate is the next most inefficient macronutrient for your body to digest.
But, not all carbs are created equally.
Some carbohydrates (fruits, veggies, and whole grains) come packed with fiber and water, which makes the body have to work harder to digest them and absorb the sugars contained in them.
This fiber and water also has the added benefit of increasing satiety.
Refined carbohydrates (as the name implies) are refined, which is codeword for “processed.”
During this processing, much of the fiber and water is removed from the foods, which means they are much easier (efficient) for the body to digest. These same foods are likely to leave you feeling less full and spike blood sugar, which sends your energy levels on a roller coaster that ultimately leaves you feeling bottomed out and hungry.
Basically, if you are trying to diet for fat loss and seeking to make your metabolism less efficient, you need to focus on consuming whole carbohydrate sources that are minimally processed.
Despite what you may have heard on the latest podcast or read on social media, fat is not the savior it’s made out to be.
It is the least satiating macronutrient of the lot.
Your body is incredibly efficient at storing dietary fat as body fat
Now, this doesn’t mean you should avoid dietary fat, as your body does require some amount of fat to function optimally, especially omega-3 fatty acids.
The final piece of the puzzle that you have a considerable degree of control over is your gut microbiome.
These mighty bacteria also have a profound impact on your metabolic efficiency, not to mention your immune function and mood since ~90% of serotonin (the “happy” neurotransmitter) is made in the gut.
The various species and concentration of these species can determine how well your metabolic machinery works.
Not only do the bacteria that colonize your gut use some of the food (namely fiber) for energy, they also are involved in signal transduction, affecting metabolic rate, hunger, satiety, etc.
Our diet has a profound impact on the makeup and density of our gut bacteria.
This may come as a surprise, but fiber serves as an important energy source for gut bacteria.
These bacteria ferment (“digest”) bacteria to produce short-chain fatty acids, such as butyrate, which have numerous functions in the body.
Therefore to ensure the health and prosperity of your gut bacteria, you will want to eat a diet rich in fibrous carbohydrates, including fruits, vegetables and whole grains.
As an added benefit, these foods are also packed with vitamins and minerals and help you stay full for longer!