We’ve heard it a thousand times. If you want to get lean, calories are all that matter. Don’t worry about eating high protein, or low carb, or any other particular way, these “experts” claim: a calorie is a calorie.
And it turns out the calories are often wrong too.
The “all calories are created equal” approach does not consider something called TEF, or the Thermic Effect of Food. And once you understand how TEF works, it will change the way you eat forever – and help you pick foods that will get you jacked and lean.
Summed up simply: Calories from certain foods count significantly more than others do, because your body has to spend calories of its own in order to break those foods down.
Put in fancier scientific terms: The thermic effect of food is the increase in energy expenditure (above resting metabolic rate) that occurs after eating as a result of the body digesting and processing specific nutrients.
Because different types of molecules have different types of chemical bonds, some require the body to spend more energy to break them down – and that’s a good thing, if you know how to take advantage of it.
It’s even possible a food with more calories listed on its label could actually have fewer effective calories than a different food that looks like a better option.
* Carbohydrate has a thermic effect of 6%.
* Fat has a thermic effect of 4%.
* Protein has a thermic effect of 30%.
With a food that’s primarily carbohydrate, like popcorn, the stated calories per serving are probably about 94% accurate in terms what your body is really getting, once we account for the thermic effect. Not far off.
On a food that’s primarily fat, like butter, the calories on the label are approximately 96% accurate. Pretty much on the mark.
But with a high protein food like a chicken breast, the calories on the nutrition facts are off by nearly a third. In fact, some studies have found protein to produce thermic effects as high as 45%.
Due to protein's massive thermic effect, a significant number of the calories in protein-rich foods effectively don’t count.
This should be music to the ears of summer barbecue lovers all over the US of A.
While carbs and fats also have a thermic cost, theirs don’t move the needle as much. As we said at the onset, not all calories are equal.
In fact, protein revs up the metabolism so much that a high protein meal can cause a brief increase in body temperature of up to two degrees.
It also doesn’t hurt that studies consistently find that of the three macro-nutrients, protein works the best to satisfy hunger and keep you feeling fuller, longer.
On a high protein diet, you can eat more, feel less hungry, and maintain the high levels of amino acids necessary to build and repair muscle – all while keep effective calories (the only kind that truly matter) at levels that still promote fat burning.
Antonio, et al, "A high protein diet improves body composition..." Journal of the International Society of Sports Nutrition, 20 October, 2015.
Segal, K., et al., Thermic effect of Food...in Lean and Obese Men of Similar Body Weight. J Clin Invest, 1985. 76: p. 1107-1112.