by Charles Poliquin
Is a calorie a calorie? What say you? There are many harmful nutrition myths sabotaging our health and fat loss, but the belief that all calories are created equally is especially ridiculous because it ignores a mountain of evidence showing otherwise. The calorie myth relies on a drastic oversimplification of how calories are used by the body.
It is spread by a number of contingents:
• The food industry intent on hawking processed food
• the USDA that has been unable to provide any useful information in the face of a mounting obesity and diabetes crisis, and
• dietitians annoyed with the idea that people could actually understand how the macronutrients influence body composition and use this knowledge to get and stay lean.
To be fair, dietitians seem to be so cautious about debunking the calorie myth because they fear that people will lose sight of the fact that if we take in more calories than we expend, we gain weight.
This is an unbreakable law of physics, also known as the first law of thermodynamics. It tells us that energy cannot be destroyed, it can only change form. So, if the energy that is entering the body is greater than the energy leaving the body, then the body will store the energy.
However, this system of energy balance is not very useful in real life because different foods are complicated mixtures that are processed in vastly diverse ways by the body.
Foods higher in protein require the body to burn a lot more calories after you eat them than those composed of carbohydrates. Similarly, foods high in fiber result in a lower proportion of the calories being absorbed by the body than those low in fiber.
Most surprisingly, some fats, which are highest in calories per unit of all food types at 9 calories per gram, actually stimulate the burning of calories. Omega-3 fats enhance the activity of something called uncoupling proteins, which lead to excess calories being burned by raising body temperature.
In addition, the average human who is counting calories grossly underestimates the amount of calories they eat every day. Not only do they think they eat less energy than they do, when asked to do a food journal most people do not correctly record food intake, indicating an inability to consciously acknowledge energy intake.
A calorie approach to fat loss isn’t very useful at its best. At it’s worst, it can be drastically counter-productive, while damaging your health and making you miserable!
This article will give you practical strategies for optimizing body composition and health. You’ll come away understanding why the “calorie is a calorie “argument is irrelevant and have essential tools to avoid the pitfalls that impede leanness.
#1: Know The Basics of Calorie Content in the Macronutrients
Calorie-containing foods are classified into the three macronutrients of protein, carbohydrates, and fat. There are also micronutrients, which are vitamins and minerals and do not contain calories.
Calorie content of the macros (plus alcohol) is as follows:
• Protein and carbohydrates both have 4 calories per gram.
• Fat has 9 calories per gram.
• Alcohol is not a macronutrient but it does contain calories—7 per gram.
Take Away: The key to body composition without constant dieting, struggle, and hunger is to understand how the different macros influence hunger and use that knowledge to your advantage.
#2: Favor High-Quality Protein For Reduced Hunger & Greater ‘Calories Out’
There are three acute benefits of favoring high-quality protein if you want to have greater “calories out.”
First, even though carbs and protein contain equal calories per gram, protein requires many more calories for the body to breakdown (nearly double depending on the amino acid profile of the protein).
By replacing carbs with protein, you can effortlessly increase the amount of calories your body burns. Quality is paramount here: Higher quality protein sources, such as those derived from animals, require more calories to metabolize than lower quality plant protein. Animal protein is also more readily used by the body to repair tissue.
Second, favoring foods high in protein will reduce calorie intake by reducing hunger, whereas choosing foods high in carbs and/or fat will increase hunger and calorie intake.
For example, for every 1 percent increase in protein intake, people naturally decrease calorie intake by between 32 and 51 calories daily.
Third, eating protein leads to steadier blood sugar and insulin levels, which elicits a cascade of hormones besides insulin that reduce appetite. Higher carb foods have the opposite effect, leading to more frequent hunger due to spikes and valleys in insulin and other metabolic hormones.
Take Away: De-emphasizing carbs and favoring high-quality protein is a simple way to increase the calories you burn, while reducing the calories you eat without feeling hungry.
#3: Familiarize Yourself With The Thermic Effect of Food
The thermic effect is the amount of calories it takes your body to break down food. You already know that protein has the highest thermic effect, and it is followed by carbs, and lastly by fat.
But dietary fat is not all created equally. Fats have different fates in the body, which are influenced by the other foods you eat them with. It’s not as simple as saying all fats are calorie losers. Recall that omega-3 fats stimulate calorie burning whereas other fats don’t.
Take Away: Use the thermic effect to your advantage. Whole foods in the form of animal protein, vegetables, and some fruit and nuts are king. If you eat grains, get them from whole, boiled sources that are high in indigestible fiber because fewer calories are absorbed than when you eat refined grains.
#4: Understand Alcohol Metabolism & Reduce Your Intake
Alcohol is an example of how “a calorie is a calorie” because it simply raises your energy intake without supplying any nutrition.
The body metabolizes alcohol through the liver, turning it into acetate, which gets burned by the body, displacing the burning of glucose or fat. Any extra glucose in the blood will be stored as fat until all the alcohol is gone. Along with increasing fat storage, chronic alcohol use causes metabolic derangements and inflammation.
Take Away: Avoid all alcohol if you’re trying to lose fat.
#5: Avoid Foods that Trigger Greater Food Intake: Sugary Carbs & Processed Fat
Carbs, especially those with a high-glycemic response, stimulate a pathway in the brain called the hypocretin network that induces sleep and slows the body’s use of energy. High-glycemic carbs are also the worst culprit for increasing food intake, particularly when paired with processed fat.
Protein and certain fats, such as those high in omega-3s, have been found to stimulate the orexin pathway in the brain, which opposes the hypocretin network in the brain. When the orexin network is activated, you are energized and feel reduced hunger
Take Away: Understand that the points presented here are general effects of the macronutrients on calorie intake that can guide your food choices. Eating in real-life is often more dynamic and hunger is influenced by more than just the proportion of macros eaten.
#6: Avoid High-Fructose Foods—Fruit Is OKAY
A comparison of two sources of sugar, glucose and fructose, provide a classic example of how the human body uses calories in different ways.
Fructose is a sugar in fruit and is also present in high-fructose corn syrup (HFCS) and honey. Glucose is a found in most carbohydrates and the human body can manufacture glucose out of amino acids or liver glycogen.
After you eat fructose, it enters the digestive tract and is almost entirely processed by the liver, whereas other sugars such as glucose are released into the bloodstream to be used as energy by cells.
The liver can do one of two things with fructose:
• Store it as liver glycogen, which will then be released to supply glucose when blood sugar is low, or
• Store it as fat if liver glycogen stores are full.
Simply, if equal calories of fructose and glucose are consumed, fructose is more likely to be stored as fat than glucose because liver glycogen stores are small and not much fructose can be deposited there.
Eating reasonable amounts of fructose from whole foods (fruits and vegetables) is unlikely to be a problem, but this is not what most of the American population is doing. The western diet has fairly large amounts of fructose from HFCS, typically in liquid form, which appears to be the most metabolically damaging.
Another problem with fructose is that it doesn’t decrease sensations of hunger in the same way as glucose. It doesn’t cause a decrease in the hunger hormone ghrelin, so carbohydrates high in fructose don’t reduce hunger to the same degree as those high in glucose.
Take Away: A diet high in fructose from non-whole food sources is more likely to lead to fat gain than one with the same amount of glucose. Eliminate it.
#7: Adopt a High-Protein, Lower Carb Lifestyle: The Long-Term Effect of Protein
The most powerful effect of protein for body composition and fat loss is evident over the long run. The magic happens with higher-protein diets because lean muscle mass is preserved.
When you lose weight by restricting calories, you will lose both body fat (good) and muscle mass (bad), causing the body to burn incrementally fewer calories. Resting energy expenditure is decreased by a couple of hundred calories daily, but calorie intake rarely goes down to compensate. This is a common reason that fat loss plateaus and fat regain occurs.
Increasing the calories you get from protein is the only way to prevent the loss of lean muscle mass because the amino acids in protein stimulate protein synthesis to keep the muscle intact. Lifting weights enhances this effect.
For example, a short, 31-day study that compared the effect of three different protein intakes (the RDA of 0.8 g/kg, double the RDA of 1.6 g/kg, and triple the RDA of 2.4 g/kg for protein) as part of a calorie-restricted diet illustrates this:
All groups lost about the same amount of weight, but the two highest protein dose groups lost about 0.3 kg more fat than the RDA group (not a large amount, but subjects were all normal-weight at baseline and this was a short study):
• For the RDA dose of 0.8 g/kg of protein group, 58 percent of the weight lost was lean mass and only 42 percent was fat.
• For the 2xRDA dose of 1.6 g/kg of protein group, only 30 percent of the weight lost was lean mass and 70 percent was fat.
• For the 3xRDA dose of 2.4 g/kg of protein group, 36 percent of the weight lost was lean mass and 64 percent was fat.
Take Away: The power of getting calories from higher protein, lower carb whole food sources is profound for improving body composition and aiding fat loss.
Be aware that lower carb does NOT mean zero or very low carb. Optimal carb intake for fat loss will be individual and falls in a wide range (20 to 150 grams a day).
#8: The Optimal Diet For Fat Loss is Not A Mystery & There’s No Magic Bullet
Whole foods are rarely one thing or another. The exception is some workout nutrition products and those used in scientific studies to assess the effect of calories on body composition. It is this highly controlled scientific study of calories that promotes the “calorie is a calorie” lie.
The catch is that no one lives under experimental conditions and the foods we should be eating for life are complicated mixtures, providing an array of vitamins, mineral, antioxidants, and fiber, along with calories.
The calorie is calorie nonsense distracts our focus from the fact that it’s no mystery how to lose fat, promote body composition, or eat for health. Humans just don’t seem to like the answer: Whole protein, a lot of vegetables, fruit, nuts and beneficial fats, and other select whole foods that are high in indigestible fiber.
Take Away: In an environment where processed higher carb and fat food is the norm, the calorie approach could be relevant. For health, leanness, and the prevention of metabolic diseases it’s not very useful. Eat whole, real foods.
#9: Ruthlessly Protect Yourself From Food Marketing
The “calorie is a calorie” argument is widely used by the processed food industry to sell products engineered to help you lose weight. They don’t tend to work, being low in nutrients, high in chemical additives, and favoring a higher carb, lower protein ratio that leaves people hungry.
Even non-refined packaged foods are processed in a “recombining” process. For example, conventional yogurt is made by separating milk into fats, protein, miscellaneous solids, and liquids, and then recombining the ingredients in new proportions into reduced fat, high-protein, or whole fat yogurt.
Although, savvy eaters know that health claims on food labels are lies, the general population is not so informed. And your average kid has no idea that what they’re being told in TV food commercials and Internet marketing is nonsense.
Take Away: Teach yourself and your kids to ignore food marketing. Educate yourself from scientifically reputable nutrition sources and question everything.
Acheson, K., et al. Protein Choices Targeting Thermogenesis and Metabolism. American Journal of clinical Nutrition. 2011. 93(3), 525-534.
Pasiakos, S., et al. Effects of high-protein diets on fat-free mass and muscle protein synthesis following weight loss: a randomized controlled trial. The Journal of the Federation of American Societies for Experimental Biology. 2013. 9, 3837-3844.
Kamani, M., Schoute, J., et al. Activation of Central Orexin/Hypocretin Neurons by Dietary Amino Acids. Neuron. 2011. 72, 616-629.
Agrawal, R., Gomez, F. Metabolic Syndrome in the Brain: Deficiency in Omega-3 Fatty Acid Exacerbates Dysfunctions in Insulin Receptor Signaling and Cognition. 2012. Publish Ahead of Print.
Bittman, Mark. Is a Calorie a Calorie? The New York Times. 20 March 2012. Retrieved 7 January 2014. http://opinionator.blogs.nytimes.com/2012/03/20/is-a-calorie-a-calorie/?_r=1&pagewanted=print.
Buchholz, A., Schoeller, D. Is A Calorie a Calorie. American Journal of Nutrition. 2004. 79(suppl), 899S–906S..
Lustig, Robert. Still Believe “A Calorie Is a Calorie? The Huffington Post. 27 February 2013. Retrieved 7 January 2014. http://www.huffingtonpost.com/robert-lustig-md/sugar-toxic_b_2759564.html
Spreadbury, I., et al. Comparison with Ancestral Diets Suggests Dense Acellular Carbohydrates Promote Inflammatory Microbiota, and May Be The Primary Dietary Cause of Leptin Resistance and Obesity. Diabetes, Metabolic Syndrome, and Obesity: Targets and Therapy. 2012.5, 175-189.