6 Big Myths About Calories

The Biggest Untruths Debunk

There probably isn’t a topic in nutrition that’s more tangled up in misinformation than calories, so let’s blow up some of those myths.

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Damn You, Wilburn!

Sometimes I wish Wilburn Olin Atwater hadn’t become a pioneer in the field of nutrition. I’d have been happier if he’d instead become a chimney sweep, corset maker, rag picker, or some other respectable late 19th-century profession.

Atwater was the one who calculated the calorie count of macronutrients and compiled the calorie counts for around 4,000 common foods at that time. He built this room about the size of an old-time telephone booth – called the “respiratory calorimeter” – in which he confined subjects for up to five days while measuring the input of food and oxygen and the output of carbon dioxide, urea, ammonia, and feces, all of which he’d use to calculate caloric intake.

It was so complex that 16 people were needed to read the dials and perform the math.

Since Atwater, or anybody else for that matter, didn’t know about vitamins or minerals back then, he incorrectly rated certain foods as superior to other foods. He gave little attention to vegetables and meats, while he rated alcohol and meat highly, as it was high in calories.

These were the first myths about calories in a long history of others. Sometimes I think we’d all have better off if, instead of calorie counts appearing on food labels, we simply used a “traffic light” approach: green means eat the food with impunity, yellow means moderation, and red means don’t put that f-ing stuff in your mouth unless it’s some sort of holiday.

Anyhow, here are some of those calorie myths that have spawned since Atwater’s time:

Myth 1 – Calorie Counts on Labels Are Accurate

Horsepucky is a common ingredient in calorie counts. The Food and Drug Administration allows for 20% “margin of allowance” on such labels, which means a food that’s listed as having 400 calories could have as many as 500 and still be in compliance with the law.

To be fair, the journal “Obesity” tested a sampling of popular common snack foods and found that the actual calorie counts were only 4.3% higher (1) than what the label stated, but personally, that doesn’t give me much solace about the whole calorie disparity issue.

After all, anybody eating snack foods probably doesn’t care so much about the exact number of calories contained in their polypropylene bags of Cheetos. They might think that nutrition labels are the same as fortune cookies with lottery numbers.

It’s the possible caloric disparity in healthy/healthier foods that gives me pause. Of course, that’s all the more reason to try and stick with unprocessed foods where you pretty much know what you’re getting. After all, it’s much harder to fudge the calorie count of a cup of oatmeal or a 4-ounce pork chop.

Myth 2: Your body absorbs all the calories in a food

All modern foods have their calorie count determined by them being burned in an Atwater-approved way: the “bomb calorimeter.” It looks like an ordinary Instant Pot, or something that stores your brain after you’re gone for future transplantation to a robot worker drone.

It is a box, or cylinder, with two chambers. The outer chamber is filled by cold water. When the food in the bomb calorimeter has been burned, the observer records the temperature increase. The food is 1 calorie if the temperature of the water rises 1 degree per kilogram. It has 2 calories if it rises 2 degrees. You get the picture.

When used to calculate the calorie content of food, the bomb calorimeter can be very accurate. The trouble is, our stomachs aren’t bomb calorimeters. We don’t incinerate foods, we DIGEST them, and the efficiency of said digestion is multi-factorial, the result being that we probably absorb about 90% of the caloric energy from the food we eat.

The following three (3) were discovered by Dutch researchers who weighed and analysed the stool of 25 volunteers.

• Total calories taken from food: 89.4%
• The total calories taken from fat are 92.5%
• The total calories from protein are 86.9%
• The total amount of calories specifically absorbed from carbohydrates is 87.3%

Perhaps surprisingly, women absorbed even fewer calories from food compared to men – an average of 88% versus 91.8%. They also displayed a “trend” towards less absorption of fat and carbohydrates than men, but it didn’t reach statistical significance.

These findings, if they are correct and representative of other populations than the Dutch, make you question the reliability of many of the diet and calorie studies that have been done over the past 50 years. Do past studies show that a 90% absorption rate is more reliable than a 95% one? It seems probable.

Myth 3 – The physical structure of a food or processing has no bearing on calories

Some foods are resistant to digestion for some reason (4). Let’s take almonds as an example. Although the label states that one ounce contains 168 calories per gram, digestion studies show that the average person absorbs only 129 calories per gram. Cashews are the same. An ounce has 137 calories, not the 163 listed on the label. Also, walnuts and pistachios.

It likely has to do with the sturdy cell structure of the nuts’ cell walls. Even though we pulverize them with our molars to break down the nuts, large amounts of the cells are left undisturbed. This protects them from any digestive juices or microbes and allows them to be assimilate. Pulses (grain legumes, such as beans, lentils, and dry peas) can be quite difficult to digest. This could also affect their caloric values.

Then there’s the way food is cooked. You can increase the calories in sweet potatoes by cooking them more. “release.” Raw sweet potatoes caused mice to lose weight. But, when they were given cooked sweet potatoes, the mice gained weight.

Because they were grown in different environments and likely cooked under slightly but ultimately significant differences in conditions, sweet potatoes are not the same as other fruits or vegetables.

It’s the same with meat. Mice that were fed raw meat lost 2 grams, while mice who were fed cooked meat only lost 1gram. The protein in meat is denatured and made easier to digest by cooking it.

Then there’s resistant starches, those foods whose molecular structure was changed – made more difficult to digest – by how the food was prepared or stored. Bread that is frozen and then toasted donates far fewer calories to the digestive system, as does rice or pasta that’s been cooked, allowed to cool for several hours, and then reheated. (More information here.)

Lastly, there’s the ultimate freer-upper of calories – industrial processing. The more a food is macerated, the more it’s pulverized, boiled, baked, and formed into little animal shapes, the less work the body has to do to assimilate its inherent energy.

Myth #4: Too much protein will make you fat

Even though you may eat a lot of proteins, even up to 5.5x the daily recommended intake, it will not cause you to gain additional fat. Instead, it appears to have a protective effect If the circumstances are right, you can also prevent fat from periods of increased energy intake.

Dr. Joey Antonio is a contributor to T Nation. He set out to “determine the effects of a very high protein diet (4.4 g/kg/d) on body composition in resistance-trained men and women” (9).

The study design was straightforward: Thirty healthy weightlifting women and men were randomly assigned to either a CON (control) or HP (high protein) group. Over an eight-week period, the CON group was required to keep their training and dietary habits the same.

The HP group was also given instructions to continue their normal training and dietary habits (i.e. maintain the same carbohydrate and fat intakes), but with an additional instruction to consume 4.4 grams protein per kilogram (or about 5.5 times RDA).

According to math, the HP group would consume around 800 calories more per day than the CON group. These extra calories came from protein, 307 +/69 grams, as opposed to the CON group’s 138 +/ 42 grams.

Here’s the clincher: After 8 weeks, despite eating about 800 extra calories per day – all of it from protein – the HP group experienced no changes in body weight, fat mass, or fat-free mass. Great, but you may be raising an eyebrow over the fact that the participants didn’t gain any muscle mass, either. Don’t worry. Antonio explained it in this manner:

“The lack of body composition changes in our group may be attributed to the fact that it’s very difficult for trained subjects to gain lean body mass and body weight in general without significant changes in their training program.”

So, it appears that the HP group simply wasn’t hitting it hard enough.

Bottom line: Protein can turn into body fat, but it’s unlikely. Biochemically, turning dietary fat into body fat is, as you might guess, easy-peasy, and turning dietary carbohydrate into body fat isn’t that much more difficult.

However, turning protein into body fat is a different challenge. It takes several biochemical and hormonal steps and it’s monitored closely by the liver, which metes out amino acids according to the body’s metabolic needs (tissue breakdown, tissue synthesis, catabolism, anabolism, etc.).

This means that you can be certain of the protein’s existence, regardless of what “common sense” It is possible to combine lifting with a caloric surplus to prevent fat gain.

Myth 5: One, Calorie-Rich Meal Will Help You Lose a Significant Amount of Fat

Scientists gave a group of healthy men one meal consisting of bread, jam and fruit juice. It contained 480 grams carbohydrate (about 1,900 cals), around 8 grams fat (about 70 cals), and some protein (12). For 10 hours, the scientists monitored their metabolic reactions.

The majority of carbohydrate was converted to glycogen (346g), while the remaining 133g was used as fuel. It’s true that their bodies converted some of the carbs to fat through a process called de novo lipogenesis (DNL), but it was only a measly 2 grams. That’s it. It only weighs 2 grams.

The best part was that the subjects burned 17g of fat during the 10-hour follow up. That’s 7 grams more fat than the combined total of what was in the meal (8 grams) and the fat they manufactured through DNL (2 grams), so they burned an additional 7 grams of body fat after the meal. The gross overfeeding resulted in zero net fat accumulation.

Another study involved soaking their subjects in carbs for several days. Young adults ate 150% of their daily caloric intake for five days straight. But, only 50% of the calories came from carbs (or 684 grams of extra calories per person).

The amount of fat manufactured (through DNL) by this practice was 10 times what you’d have seen if the subjects were on a maintenance diet, but it still only amounted to gaining 5 grams a day.

Five days of pigging out resulted in a loss of only 25 grams total fat, or one-eighteenth to a pound. That’s an amount so small that it probably wouldn’t even cause an anorexic to blink.

Although you may gain weight after eating piggy meals, it is very unlikely that it will be excess fat.

You could gain a pound of weight if your daily intake is 500-1000 calories per day. However, this does not apply if you consume 500 to 1000 calories more in one meal. For one thing, there’s a limit to how much food your body can turn into fat (via DNL) in one sitting.

That’s because several things happen when you eat the equivalent of all the foods from column A off a Chinese restaurant menu. Much of it’s stored as glycogen in the liver and muscles, and along with each gram of stored carbohydrate comes about 3 grams of water.

The amount of glycogen stored varies enormously from one individual to another and may be particularly large in lifters, athletes, or muscular people in general, especially if they’ve worked out that day (thus depleting glycogen to a certain degree).

Then there’s the effect the food itself has on the body. You can experience thermogenesis when you eat a lot of food. Your body’s temperature will rise as it tries to process the food (diet-induced heatgenesis). (Protein is most important. “expensive” To metabolize, while fat is the most expensive.

Some of it’s also burned up from NEAT, or non-exercise activity thermogenesis, which is the energy we expend for everything that’s not sleeping, eating, dancing, or doing sports – things like walking, typing, performing yard work, and even fidgeting.

The rest of the actual weight gain is heavily influenced by the amount of sodium and water in the meal, both of which affect blood volume, and then there’s the actual weight of the food that’s slogging through your digestive tract. That’s the bulk of it. “gained” weight doesn’t stick around, though.

Myth 6: Lose 3500 Calories to Burn 3500 Fat

It’s an almost universally agreed upon fact that you have to reduce caloric intake 3500 calories To lose one pound of fat, you must be below the baseline. We know this because, back in 1958, a guy named Max Wishnofsky burned a pound of fat in, yep, a bomb calorimeter and saw that it gave up about 3500 kilocalories’ worth of energy.

And we all swallowed it, hook, line, and pork rind without realizing, again, that we’re not bomb calorimeters and that, moreover, weight loss is governed by a slightly more complex mathematical formula and doesn’t continue in a linear fashion.

It took a mathematician by the name of Kevin Hall, Ph.D., to figure out that over the course of the first year of a diet, people only lose about half of what’s predicted (13). The true number of calories required to lose a pound of fat is closer to 7,700.

Hall’s words are more powerful than your anger and frustration.

“I suppose some people will be bummed out, but we believe it’s better to have an accurate assessment of what you might lose. That way, you don’t feel like a failure if you don’t reach your goal.”

The problem with the 3500-calorie rule is that it did not take into account the fact that the body adapts in many ways to reduce or eliminate the effects of a reduced caloric intake. It doesn’t account for gender, either, or the fact that the metabolic rate drops as body weight decreases.

It also doesn’t take into consideration that counting calories is, for the reasons I laid out above, a woefully inexact science.

References

References

1. Jumpertz R et al. Food label of accuracy for common snacks Obesity (Silver Spring). 2013 Jan;21(1):164-9. PubMed.
2. Southgate DA et al. Calorie conversion factors. A reassessment experimental of the factors used for the calculation of the energy values of human diets. Br J Nutr. 1970 Jun;24(2):517-35. PubMed.
3. Wierdsma NJ et al. Bomb calorimetry: The gold standard for assessing intestinal absorption capability. J Hum Nutr Diet. 2014 Apr 27 Suppl 2 :57-64 PubMed.
4. Cardona-Alvarado MI et al. Consumption of Almonds and Walnuts Modifies PUFA Profiles and Improves Metabolic Iflammation beyond the Impact of anthropometric Measure. The Open Nutrition Journal. 2018 Oct;12(1):89-98.
5. Acheson KJ et al. Glycogen synthesis versus Lipogenesis in man after a 500g carbohydrate meal. Metabolism. 1982 Dec 31(12):1234-40. PubMed.
6. Schwarz JM et al. There are short-term changes in human carbohydrate intake. Inspiring effects on the production of hepatic sugar, de novo and lipogenesis, as well as whole-body fuel selection. J Clin Invest. 1995 Dec;96(6):2735-43. PMC.
7. Dunn R. Calories: The Hidden Truths Scientific American. August 27, 2012.
8. Hall KD et al. Implications for body weight regulation: Energy balance and its constituents Am J Clin Nutr. 2012 Apr;95(4):989-994. PMC.
9. Antonio J et al. A high-protein diet (4.4% g/kg/d), can have an impact on the body composition of resistance-trained people. J Int Soc Sports Nutr. 2014 May 12:11:19 PubMed.
10. Leaf A et al. The Effects of Overfeeding on Body Composition: The Role of Macronutrient Composition – A Narrative Review. Int J Exerc Sci. 2017;10(8):1275-1296. PMC.
11. Bray GA et al. In a metabolic chamber, the effect of protein overfeeding upon energy expenditure was measured. Am J Clin Nutr. 2015;101(3):496-505. PubMed.
12. Leaf A et al. Can you binge on food and still be fat? Examine.
13. Webb D. Say Goodbye to the 3500-Calorie Rule Today’s Dietitian. 26(11):36.

This is a great article! It’s a great hobby to count calories, but it has its limits.

Many thanks! You are right about counting calories. I am prone to do it all myself, even though my knowledge is better.

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Well said (despite the jocular writing style).

Sir, you have wound me. You have wound me, sir. I was first interested in life sciences as a career after I read a biology textbook with a humorous writing style. Guess it doesn’t work for everybody, though. That’s okay.

For what it’s worth, I enjoy your jocular style of writing immensely, along with all the incredibly useful content.

So in other words, it’s still 3500 calories, but it’s hard enough to feel like 7000 because the body works against.

A good article must be informative and entertaining to reach the maximum number of people.

It’s fun and educational. It doesn’t get much better than that.

Yes, it would. Physics says it’s about 3500, but physiology makes the number closer to 7000.

That’s always been my philosophy. Thanks!

Pharmocology is here!

It’s a great article. Very well said. Thank you, TC

After 41 years of working at an electric power generator plant, I thought I’d never hear the end of it. “bomb calorimeter” again. It made me smile to see it in the article.

There was a job I began in 1971. We used #6 We use fuel oil to power our steam turbines that generate electricity. Up until the oil crisis of 1973-1974 we purchased BTU’s and not barrels of oil. For BTU content analysis, the amount of unloaded oil was measured in barrels. At the end of the year we compared the BTU’s we received with what we were charged. We either received a rebate or paid what we underpaid for the BTU’s we received.

My work area was responsible for running our bomb calorimeter to calculate the BTU’s per barrel. This was a full-time job that I was fortunate to avoid getting lost in the monotonous task. We all tried to avoid getting sucked in to this fear.

Many ships were full of our products. #6 Multiple samples were taken from fuel oil. The oil guy ran bomb calorimeter test every day.

After 1974 it wasn’t as bad because we only need to test BTU’s per barrel to run efficiency tests. These were generally once a year.

Ha! Ha! It makes sense though.

Excellent article, TC. I have a question. “absorbtion percentages” The Dutch study that I have quoted is purportedly what is known as the “thermic effect of food” Or something completely different? What I’ve commonly read shows a greater disparity between fats (0-3%), carbs (5-10%) and protein (20-30%).

Calories used be a problem for me. Then I let it go. Recently, my WTFs have come back. We now have a unit for measuring. The measure refers to the amount of energy needed to heat 1 kilogram of water 1 degrees Celsius.
These are just a few.
Labels can be misleading. Intake happens, of an amount that can’t be reliably measured, and what you crap out isn’t put back i the bomb calorimeter to measure the difference, the difference between what unreliably went in and what came out…AND we don’t power our bodies as a steam engine with the energy captured by burning the fuel and turning it to into steam and whatever, but instead a series of chemical reactions.
So all the devices that say you’re in precisely a 500 Calorie deficit, all the plans, all the programs…they’re guessing?
Is fasting bad? Ghrelin and Leptin and cortisol and insulin…OH MY
What can we be certain of?

I suspect is has to do with enzymes, the pH of surrounding fluids, the chemical nature of the macro, and probably a few other things I haven’t thought of (thanks!).

While I was educated in mathematics, I worked in boiler controls which used feedback loops to control.

I have never lost fat by counting calories, but I do use feedback systems. When asked how I diet for contests, my answer is simple: “I call it an idiot’s diet.”

I totally changed my diet. I eat the same amount of macros as before, and eat similar food. I will cut down on starchy carbs if I want to lose weight. “feedback”. If I didn’t lose any I cut out a little more. If I lose strength, I add it back.

TC, if it’s any consolation, I’ve followed your work (and in turn the work of Poliquin, Staley, Duchaine, Thibaudeau and numerous others) since 1996, In large part, this is because You are a comedian.

I studied biology at Washington University in St. Louis, and all those texts were as dry as Hillary Clinton’s… well… you know.