“I Just Don’t Believe All Calories Are The Same”
Here’s the thing CALORIES are the same.
ALWAYS
A calorie is just a unit of energy.
“From a thermodynamic viewpoint, a calorie is of course a calorie. The first law of thermodynamics states that energy can be neither created nor destroyed, but only transformed. Thus, the human body is constantly transforming energy—in this case, kilocalories—by combusting foodstuffs to produce heat.” – Is A Calorie a Calorie?
But food?
Food with all of it’s constituent parts, isn’t just a uniform unit of energy.
On the most basic level we know that per unit of mass (gram) carbs, proteins fats and alcohol all have different caloric values. (proteins and carbs are pretty damn close and get rounded to 4cals per gram).
But very few foods we eat are composed of ONLY digestible macronutrients (fats carbs and proteins).
So, I’m in agreement and not going to argue that 100 calories of chicken breast and broccoli is the same as 100 calories of Oreo’s and ice cream.
Except, it is.
But, in the real world, we pretty much all know, those CALORIES are different.
It’s not the Calories, It’s the Food.
Wait, But What?
I know, “I thought you said, a calorie is a calorie”
Processed food doesn’t matter and all that does for weight loss is an energy deficit.
Those are still very true statements.
“independently of the method for weight loss, the negative energy balance alone is responsible for weight reduction.” – Fat Loss Depends on Energy Deficit Only, Independently of the methof for Weight Loss
Here’s the thing, it’s not the calories you put in your mouth that matter.
What REALLY matters, the thing that funks up the way people perceived the energy balance equation, and a big reason why folks think “a calorie isn’t a calorie” is that what really matters isn’t the calories you eat, but rather,
The calories YOU ABSORB through digestion.
Those are the actual Calories In, in the energy balance equation.
Not necessarily calories into the mouth, but absorbed into the body.
If you don’t absorb calories you ingest, they can’t affect your actual energy intake..
Factors Affecting Food Absorption
Fiber
“dietary fiber is the edible parts of plants, or similar carbohydrates, that are resistant to digestion and absorption in the small intestine.”- Effects of Dietary Fiber and It’s Components on Metabolic health
Basically, fiber is the part of plant products we can’t digest.
That’s why it can make you poop.
The body tries to break it down, but(t) for the most part, it ain’t happening.
Fiber just slides along the digestive tract, absorbing water, picking things up and blocking some nutrients from absorption, along the way.
Here’s the long and short of it when it comes to absorption of calories from the diet:
Higher Fiber Content = Fewer Nutrients Absorbed.
*this isn’t always the case for “fiber”, the type of fiber matters, but for the most part more fiber leads to less absorption.
“dietary fiber may decrease a diets metabolizable energy (ME), which is gross energy minus the energy lost in the feces, urine and combustible gases. Baer et al. [33] observed that an increased consumption of dietary fiber resulted in a decrease in the ME of the diet. This may be attributed to the fact that fat digestibility decreased as dietary fiber increased. Also, as dietary fiber intake increases, the intake of simple carbohydrates tends to decrease. Although, dietary fiber still contributes to the total caloric content of a diet, it is much more resistant to digestion by the small intestine and even somewhat resistant in the large intestine.”- Effects of Dietary Fiber and It’s Components on Metabolic health
Basically, the nutrients get caught up in the fiber or it blocks the interaction with the walls of the small intestine and some nutrients pass through the GI tract unabsorbed.
“Nutrients” includes cabs, fats and proteins.
Yes, the macronutrients that have calories.
“insoluble fiber increases the passage rate of foodstuff through the GI tract thus resulting in a decreased absorption of nutrients, namely simple carbohydrates.” – Effects of Dietary Fiber and It’s Components on Metabolic health
Increased fiber can lead to pooping out calories.
Truth is, you already poop some calories out.
You shouldn’t fret about getting too much fiber.
That’s really rare in our society, and just about any society.
If you’re getting between 30-70 grams a day, most people seem to be ok and you probably wont block too much nutrient absorption.
Plus, fiber confers a whole host of health benefits.
“A high level of fiber intake has health-protective effects and disease-reversal benefits. Persons who consume generous amounts of dietary fiber, compared to those who have minimal fiber in-take, are at lower risk for developing; Cardiovascular health disease, hypertension, diabetes, obesity, and certain gastrointestinal diseases.“- Health Effects of Dietary Fiber
So eat some. (and you’ll probably eat less total calories too cause it fills you up).
Thermic Effect of Food (TEF)
Digestion isn’t a passive process.
It takes energy to breakdown, partition and store food.
“Stimulation of adenosine triphosphate (ATP) hydrolysis during intestinal absorption, initial metabolic steps and nutrient storage are responsible for this food thermic effect.”-Thermic Effect of Food and Sympathetic Nervous System Activity in Humans
TEF is sometimes referred to as DIT and is one of the three determinants of your daily caloric expenditure along with basal metabolic rate (BMR) and activity.
“Diet induced thermogenesis (DIT) can be defined as the increase in energy expenditure above basal fasting level divided by the energy content of the food ingested and is commonly expressed as a percentage. It is, with basal metabolic rate and activity induced thermogenesis, one of the three components of daily energy expenditure.”- Diet Induced Thermogenisis
In fact digestion or TEF is commonly responsible for 5-15% of your total daily calorie expenditure.
Why the 10% Variance?
Diet Composition.
The measured thermic effect of macronutrients is as follows:
- Fat: 0-3%
- Carbohydrates: 5-10%
- Proteins: 20-30%
Yes, you’re reading that correctly.
Protein Takes 20-30% of the Calories Consumed Just to Fully Digest.
The high DIT of protein alone can have a small but noticeable effect on overall energy balance.
“The high DIT of protein therefore affects energy balance. Whitehead et al. used a room calorimeter to assess 24-h energy expenditure in subjects on a high-protein diet (36% energy from protein) against two with 15% energy from protein, one high in carbohydrate and the other high in fat. The authors reported that energy expenditure was 297 kJ/d higher in subjects consuming the high-protein diet (P < 0.05), which was in agreement with the increase in sleeping metabolic rate.” – A High Protein Diet for Reducing Body Fat: Mechanisms and Possible Caveats
Basically, protein is like a diet cheat code.
But it’s gotta be PROTEIN.
On TV you’ll hear things like,
“Nuts are packed with PROTEIN”
or yogurts that have,
“8 grams of protein per serving”
Just do the math.
Take the grams of protein and multiply it by 4 (calories per gram).
That’s your total calories from protein.
Divide the total number of calories in the food by the protein calories and you’ll soon find out,
Nuts are primarily a FAT source and yogurt is primarily a CARBOHYDRATE source. #mathismyfriend
Gut Bugs
Gut Health
Gut Microbiome
Is the cool new, popular thing in health and science.
“such is the interest in the gut microbiota, it has been reported that in 2017 alone, approximately 4000 research papers on the topic were published, with more than 12,900 papers published in the preceding four years” – Precision Nutrition and the Microbiome, Part I: Current State of the Science
And because of this there is a LOT of misinformation out there.
When it comes to the microbiome the guruism is strong.
“the gut microbiome has become the conspiracy theory of nutrition: It’s where people go to prove somethings dangerous when there’s really no evidence that it is”- The Case For diet Soda: It gets a bad rap, but the Research tells a Different Story
One of my favorite podcasts did a whole episode with Gabrielle Fundaro (vitaminphd on Instagram) about gut health (what she got her Ph.D in) and pseudoscience because, right now the gut is at the forefront of the BS train.
Guts Role in Digestion
One of the things we are pretty sure about is that those guys and gals that live in your intestines play a role in digestion and therefore nutrient absorption.
“Microbes in the large intestine allow the host to salvage energy from otherwise indigestible carbohydrates and proteins by providing a variety of enzymes required for their metabolism. For example, Bacteroides thetaiotaomicron (B theta), a prominent commensal gut microbe, produces 226 predicted glycoside hydrolases and 15 polysaccharide lyases, whereas the human genome only contains 98 potential glycoside hydrolases. Therefore, the gut microbiota provides the human host an ability to degrade plant polysaccharides, enhancing the host’s energy balance.” – Effects of Gut Microbes on Nutrient Absorption and Energy Regulation
That’s right, those little bastards have the ability to break down and literally transform unusable carbohydrates and protein constituents into usable, absorbable short chain fatty acids (SCFA).
How much of this happens and how much of these SCFA’s do we actually use/ absorb?
We Don’t Know…Yet.
The gut microbiome is such a new and emerging area of research that (most the good articles are not open access and that made this blog much harder to write, thanks journal jerks) we’re just at the starting line of HUMAN research on it.
While we know these reactions take place in the gut, we don’t know what the end result of those reactions actually is.
Hell, we don’t actually know, for certain, what a “good” or “healthy” gut microbiome looks like, other than it seems to be that the higher the level of diversity, the better,
“such is the inter-individual variability that scientists still grapple with what constitutes a “healthy” microbiota. One feature of a poorly functioning microbiota that is incapable of serving its host to its full potential is low microbial diversity.” – Precision Nutrition and the Microbiome part II: Potential Opportunities and Pathways to Commercialisation
We also do know that diet composition has an influence on the bugs present in the gut microbiome,
“diet influences the composition of the gut microbiota has been confirmed in several studies. Even short-term dietary changes (four days) have been shown to alter human gut microbiota composition. In this particular study, David et al. reported that the entirely animal-based diet (meats, eggs and cheeses) had a greater impact on gut microbiota composition than the plant-based diet (grains, legumes, fruits and vegetables), resulting in a decrease in plant polysaccharide-metabolising Firmicutes (Roseburia, Eubacterium rectale, and Ruminococcus bromii) and an increase in the abundance of bile-tolerant microorganisms presumably owing to the increase in bile acid secretion as a result of high fat intake” – Precision Nutrition and the Microbiome, Part 1: Current State of the Science
We can also show that SPECIFIC strains of gut bugs tend to be more present in certain populations.
Many of those bugs seem to proliferate or degrade with exposure to different foods and environments and some of those appear to have an impact on digestion and energy absorption of the human host.
“Several of the microbial communities belonging to phylum Firmicutes are important carbohydrate fermenters and may help in the salvage of energy from unabsorbed dietary carbohydrate. Fecal SCFA (short chain fatty acids) (representing fermentation of unabsorbed carbohydrate in the colon) were increased in obese individuals. Increased efficiency of energy salvage from food may contribute to weight gain. Increasing dietary caloric load from 2400 to 3400 kcal/day in lean volunteers resulted in gut microbiota changes and an increase in the fractional energy absorption from the diet. These investigators calculated that a 20% increase in Firmicutes and a corresponding decrease in Bacteroidetes was associated with an increase in energy absorption equivalent to 150 kcal/day.“- Role of the Gut Microbiota in Human Nutrition and Metabolism
I have NO CLUE what the Fu#k Firmicutes is.
But I DO KNOW that absorbing up to 150 calories more a day do to a 20% increase in it is A LOT OF EXTRA, otherwise unabsorbed, calories.
That alone would have a HUGE effect on your daily energy balance.
To the tune of roughly a pound of mass gained a month.
I’m guessing this pound a month would mostly be fat.
But we don’t actually know if this is the case.
While it works theoretically and we’ve seen this in some animals and pretty much everyone who researches the microbiome is in agreement that the gut does play a role in energy balance, we don’t actually understand to what extent,
“Together these studies clearly and qualitatively document a role for the gut microbiota in the control of digestive efficiency, but critically these studies do not attempt to determine whether observed changes in digestive efficiency quantitatively account for the observed weight changes in the host organisms. In other words, what fraction of host weight gain/loss is due to changes in digestive efficiency caused by the modification of the gut microbiome? It remains unclear whether other energy flux mechanisms may quantitatively contribute to the effects of gut bacteria upon host energetics, and the failure of the field to comprehensively assess other mechanisms may result from the technical challenges of measuring the forms of energy metabolism performed by bacteria within the lumen of the gastrointestinal tract.” – the Gut Microbiome, Energy Homeostasis and Implications for Hypertension
Facebook relationship status; “It’s Complicated”
That’s what the microbiome is.
And with our really limited knowledge of what the hell is going on in there, we don’t actually know what to do to get the results we want.
So basically, I’m saying,
Don’t believe your friend the “nutritionist” who is selling you the pro or prebiotic supplement for your gut health and weight loss.
They probably don’t know what they’re actually bullshitting talking about.
“Interventions have highlighted the significance of inter-individual variation in terms of intervention efficacy and this is most apparent for fibre, presumably due to the ability to measure the expected outcome i.e. modulation of gut microbiota composition, increases in SCFAs. Thus, understanding why and how an intervention has failed at the individual level is as critical as understanding why and how it has succeeded. With this in mind, it seems the field is on the brink of being propelled towards precision microbiomics, where inter-individual variation is being embraced and correlation studies are beginning to be supported by causal evidence through thorough experimental validation. This will allow for the design of strategic interventions and ultimately evidence-based dietary advice at the individual level. Criteria ensuring scientific validity for microbiota-based dietary advice are, thus, critical.” – Precision Nutrition and the Microbiome Part II: Potential Opportunities and Pathways to Commercialization
So it seems that depending on YOU and YOUR Gut Bugs you could be absorbing more or less of the food you eat than someone else.
Why People Think Calories Are Not Calories
We see cool infographics like this:
some of the best fitness and nutrition graphics from jorntrommelen
and don’t understand the context.
We just focus on the calories.
See where it says
“Diet Induced Thermogenesis”
Remember the Thermic effect of food (TEF) or Dietary Induced Thermogenesis (DIT)?
That’s what the authors of the study concluded could be the cause for the discrepancy in the calories burned post meal.
“Ingestion of the particular PF meal tested in this study decreases postprandial energy expenditure by nearly 50% compared with the isoenergetic WF meal.” – Postprandial Energy Expenditure in Whole-Food and Processed -Food Meals: Implications for Daily Energy Expenditure
While the calories EATEN were the same.
The calories ABSORBED were different because the WF (Whole Food) group had to WORK harder and expend more energy during digestion,
“The removal of germ contributes to the lower protein content of refined grains and the removal of fiber-rich bran makes the remaining starch more readily digestible….. Consequently, PFs (processed foods) tend to have fewer metabolites, and thus require less enzyme production and peristalsis, simpler absorption, and less secondary metabolism, all of which demand energy expenditure“
Processed Foods Leave No Wiggle Room
When it comes to your weight, it doesn’t matter if your calories are from PF (processed) or WF (whole) foods.
Mark Haub proved that years ago with the Twinkie Diet.
As long as you’re taking in fewer calories than you consume,
YOU WILL LOSE WEIGHT
That said, a diet high in fiber and protein and a beneficial gut microbiome would increase your metabolism and decrease the amount of calories you would expect to be absorbed from a meal.
Basically, if your baseline calorie expenditure for the day is 2,000 calories and you eat 1950 calories of McDonalds you’re only going to be at a 10 calorie deficit.
If your baseline is 2,000 and you eat chicken breast and broccoli all day and you eat 2,000 calories of food, you may only absorb 1,800 calories.
Eating the chicken breast and broccoli meal could end up in a caloric deficit even when eating at caloric maintenance or even a small surplus.
*Btw, so we’re all on the same page, I’m making these numbers up just for easy examples.
**If you’re “eating at caloric maintenance”, by definition, means you’re in perfect energy balance. But, hopefully, you get my point.
In the end, if all things are equal (caloric intakes are the same) the whole food diet that forces your body to work harder and expend more energy during digestion than its processed food counterpart
This should result in fewer calories being absorbed.
Will Whole Foods Ensure I Don’t get Fat?
Nope, plenty of people gain weight eating healthy, whole, foods.
Nuts and Fatty fish like salmon are notorious for this.
They’re packed with calories, especially fat, which at 9 calories per gram can add up really fast.
It doesn’t matter what the processing level of the food or “healthyness” is, if you’re in a caloric surplus, you’ll gain weight.
However, whole, fiber and protein rich, foods are kinda like a weight loss cheat code and do usually confer a caloric “buffer zone” of sorts.
About Roy:
