Calories in Vs. Calories Out

Many “experts” have called bullshit on the CICO “calories-in-calories-out” model and people will continue to argue and debate, and we shall let them fight, but regardless of the arguments, calories do and will always matter.  Whether you want to drop body fat and lose weight, gain muscle or just maintain your current weight, calories count.

So what does this mean?  Well, you can watch this video, but read the article first!

Calories In:  Everything you consume over the course of the day that contains calories.  The foods and beverages that we consume will be referred to as the calories in.  Cool?

Calories are made up of macronutrients which are:

  • Proteins (4 calories per gram)
  • Fats (9 calories per gram)
  • Carbohydrates (4 calories per gram)
  • Fiber (believe it or not, fiber does have a caloric value.  The exact number is hard to pinpoint since it depends on the type of fiber and research shows that it’s less than 4 calories per gram, but more than zero.)
  • Alcohol (though some will argue alcohol is not really a macronutrient, but for the sake of tracking calories we will add it to the list; it contains 7 calories per gram)

Calories Out:  These are the calories we burn.  Every single activity burns calories, even me typing up this article.

Calories out are comprised of 4 main outputs of energy:
→ RMR/BMR: Resting Metabolic Rate / Basal Metabolic Rate – These are often times used interchangeably but are slightly different.

  • BMR  typically requires a strict set of criteria in place.  It’s commonly done at a testing facility in a dark room upon waking after 8 hours of sleep and 12 hours of fasting to ensure that the digestive system is inactive.
  • RMR is a measure of the body’s metabolic rate in a relaxed state, with a far less strict set of criteria to measure

→ TEF: Thermic Effect of Food – The increase in metabolic rate after ingesting food.

→ TEA: Thermic Effect of Activity – The energy expended throughout your daily activity.

→ NEAT: Non-Exercise Activity Thermogenesis – The calories you don’t realize you are burning. These are calories burned through subconscious movement such as walking, fidgeting, cleaning the house, shopping…any movement.

Now that we have a basic understanding of what happens in the body in regards to calories in vs calories out, let’s talk about how this affects our change in body stores and body composition.  My buddy Jay over at aworkoutroutine has done an incredible job at illustrating this, so credit to him for the following graphics.


The above images are spot on, and they are an accurate representation of what would happen if you follow what it says, but what’s important to note is that the CICO or Calories in Calories Out model is much more complex than people think.

Let’s break this down one step further:

Caloric Surplus (consuming more calories than you are burning) To explain this in a very simple way, your body requires energy (calories) to perform daily functions. Whether you’re brushing your teeth, eating, running, lifting or watching Netflix, you’re still alive and breathing and that requires energy.  Your body will use the energy it needs to carry out these day to day functions and at some point, it will be enough.  Once your body used all of the calories that were needed you now have extra left over, which is the surplus. Since these calories are not being “burned” they are being stored in your body to be used at a later time. These surplus calories can be stored as fat, muscle, glycogen, etc.

Caloric Deficit  (consuming fewer calories than you are burning) Under these circumstances, your body has used up the calories you provided it, and it must now look for alternative energy sources.  Your body will now tap into it’s stored and reserves for energy.

Maintenance (calorie intake is equal to calorie output) When your body is at maintenance your are not in a caloric surplus or deficit.  You are simply meeting your energy demands, no more, no less.  One major thing to keep in mind is maintenance is a moving target and can fluctuate from day to day.

*Note: the energy balance equation is not as perfect as it seems and it’s a bit more involved than manipulating a few numbers.  We have to take into account the different thermic effects of different foods, the changes in RMR/BMR as we gain/lose weight, hormone levels, water intake, changes in daily activity and many more variables.

Yeah, so it’s not as simple as Calories in – Calories out, but if you track your intake, it will allow you to manipulate variables more accurately, thus making you more successful at reaching your goal.

References Speakman JR, Selman C. Physical activity and resting metabolic rate. Proc Nutr Soc 2003;62:621–34[PubMed] Schoeller DA. The energy balance equation: looking back and looking forward are two very different views. Nutr Rev. 2009 May;67(5):249-54. Martin CK, Heilbronn LK, de Jonge L, et al. Effect of calorie restriction on resting metabolic rate and spontaneous physical activity. Obesity (Silver Spring). 2007;15(12):2964–2973. doi:10.1038/oby.2007.354. Ballor DL, Poehlman ET. Exercise-training enhances fat-free mass preservation during diet-induced weight loss: a meta-analytical finding. International Journal of Obesity (2005). 1994;18(1):35–40. Kraemer WJ, Volek JS, Clark KL, et al. Influence of exercise training on physiological and performance changes with weight loss in men. Med Sci Sports Exerc. 1999;31(9):1320–1329. Ravussin, E., Burnand, B., Schutz, Y., Jequier, E. 1982. Twenty-Four-Hour Energy Expenditure and Resting Metabolic Rate in Obese, Moderately Obese, and Control Subjects. Am. J. Clin. Nut. Vol. 35:566–573 S peakman, J.R., Krol, E., Johnson, M.S. 2004. The Functional Significance of Individual Variation in Basal Metabolic Rate. Phys. Biochem. Zool. Vol. 77(6):900–915 McNab, B. K. 1997. On the Utility of Uniformity in the Definition of Basal Rate of Metabolism. Physiol. Zool. Vol.70; 718–720. Reed GW, Hill JO. 1996-2-1. Measuring the thermic effect of food. The American Society for Clinical Nutrition, Inc Denzer CM, Young JC. The Effect of Resistance Exercise on the Thermic Effect of Food Int J Sport Nutr Exerc Metab. 2003 Sep;13(3):396-402.[PubMed]

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