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June 27, 2020

How We Lose Weight: Understanding the Science behind Energy Balance


As many of you might already know, the term “Energy Balance” can be characterized as simply the interplay of a person’s energy input and energy output. It is commonly known as “Calories in versus Calories out” in fitness parlance.


Energy input is basically the number of calories you consume each day while energy output is the amount of energy that your body expends within the day.


Here are three generally accepted rules about energy balance in relation to weight management:


  • If your energy input is the same with energy output, you will maintain your weight.


  • If your energy output is greater than your energy input, you will lose weight.


  • If your energy input is greater than your energy output, you will gain weight.


Experts illustrate the dynamics of “Calories in versus Calories out” by using an actual scale which tips weightier to one side depending on the modifications that a person does on either his diet or physical activities or both.


It makes sense, doesn’t it?


If a person decreases his daily calorie intake by 1000 Kcal, even if he does not increase his energy output, he will most likely lose weight based on the third general rule.


In the same way that if a person significantly increases his physical activities by putting an additional hour in his daily exercise routine, then he will most likely lose weight without decreasing his daily calorie intake based on the second general rule.


But is it really that simple? How do we explain such an instance when we have followed a certain diet to the letter and even increased our exercise activities but we suddenly stopped losing weight sometime in the regimen, like we hit an unseen roadblock?


There is a movement in the fitness world which suggests that this basic notion of “Calories in versus Calories out” has become antiquated. It has even become a myth to some.


According to the proponents of this movement, there have been studies which show that by just shifting to a high protein, high fibre diet even at the same total calorie intake, it is more likely that a person will lose more weight and more fat without even modifying his exercise activities.


This school of thought suggests that the relationship between energy input and energy output is far from just being linear or simply inversely proportional. The supporters posit that the factors affecting their interplay are deeply rooted in science much more than how we think they are.


Thus, the mystery, as to why there are seemingly unexplainable discrepancies in explaining the tipping of the scales between energy input and energy output, can be unlocked by understanding energy balance in the contexts of Biochemistry and Physiology.


The Biochemistry and Physiology of Energy Balance.


Looking at it beyond the surface, energy input necessarily involves a person’s intake of the three major macronutrient groups – protein, carbohydrate, and fat. Nutritionists say that the net absorption of these dietary energy components varies among individuals and is dependent on the specific foods eaten, how they are prepared, and other intestinal factors (Hall, et.al, The American Journal of Clinical Nutrition, 2012).


Energy output can be broken down into a person’s Basal Metabolic Rate (BMR), Nonexercise Activity Thermogenesis (NEAT), Exercise Activity Thermogenesis (EAT) and Thermic Effect of Food (TEF).


  • BMR is the amount of energy required to keep your body functioning at rest which include breathing, brain functions and other essential bodily functions whether we are awake or asleep. According to studies, BMR accounts for 60 to 70 percent of energy that a person expends per day.


Because BMR is affected by several physiological factors including but not limited to a person’s age, sex, height, weight, and genes, it is not significantly modifiableto alter daily energy output. Although, to some extent body composition also affects BMR, it can be suggested that BMR can be limitedly modified through losing or gaining weight or increasing muscles.


  • NEAT is the amount of energy that we expend when a person is not sleeping or exercising. It could be anything from your usual day-to-day walk or taking the stairs rather than the elevator or washing your car. According to studies, NEAT accounts for 10 to15 percent of energy that a person expends per day. NEAT is also the most modifiable among these components to alter daily energy output.


  • EAT, on the other hand, is the amount of energy that we expend when we intentionally engage in activities in the gym while we do our regular exercise routines or morning runs and brisk walks, among other things. According to studies, EAT accounts for 5 percent of energy that a person expends per day. EAT is very modifiable to alter daily energy output depending on the duration, difficulty, intensity of the exercise activity as well as the body composition of a person during the activity.


  • TEF is the amount of energy that our body expends to digest, process, absorb and excrete nutrients from the food that we eat. According to studies, TEF accounts for 10 percent of energy that a person expends per day. TEF is slightly modifiable to alter daily energy output through our selection of food.


According to Food and Nutrition Research on Thermic effect of a meal and appetites in adults (Ravn, et.al, 2013), proteincauses higher TEF (20 to 30 percent of the energy content of ingested protein) compared to carbohydrate (5 to 10 percent) and fat (0 to 3 percent). These figures show that we expend more energy digesting protein than carbohydrate or fat.


Why knowing these components matter in the quest to lose weight?


Breaking down these components and going beyond the basic notion of “Calories in versus Calories Out” in relation to weight management would allow you to be more discerning with and more in control of the different aspects of your fitness program.


Just as the adage which says that knowledge is power, you will be able to confidently take greater strides toward your fitness goals without being misled by false advertisement and commercialism that are preponderant nowadays because you know your stuff – you understand the dynamics.



So, how does understanding energy balance REALLY contribute to losing weight?


It really boils down to knowing the components of the balance which you can control or modify the most.


Take for example client below Max, he has an incredibly busy corporate job, so with Max we focused on having his diet setup to create the calorie deficit, so he did not have to complete endless amounts of cardio to get the fat shifted.


If you want results like Max from London please complete the application here and book in a FREE Discovery call with me or my team


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Remember that one of the keys to losing weight is to maintain a calorie deficit. A calorie deficit occurs when you consume less calories than you expend.


However, as I have overemphasized in this article, it does not just simply mean your “Calories in versus your Calories out”. It is a matter of knowing which component to tweak to find a routine that you are comfortable with without letting your overall well-being suffer.


On Energy Output


We have established that each person is unique in terms of energy consumption because of our biological differences. Some people have slower metabolism than others, so a 2000 Kcal daily calorie intake would not look the same for a person who is born with a faster metabolism, right?


But that does not mean that the person with a slower metabolism would just end up blaming his genes or worse kill himself in the gym by overworking just to lose the weight. Instead, by understanding and utilising the knowledge that we have gained from studying energy balance, he can achieve the same results as those with a higher metabolic rate.


Now we know that among the four components of energy output, NEAT is the most modifiable. Consciously adding more movements to one’s daily nonexercise-related routine by volunteering to do errands for mum or always taking the stairs, choosing to stand up while working on your computer will contribute greatly to your goal of losing weight without overcompensating on your exercise routine or getting yourself starved.


On Energy Input

In the same way that blindly shifting to and self-directing a high protein diet just because digesting protein expends more energy and therefore would least likely contribute in storing body fat than carbohydrate is reaching too far.


Advancements in Diet and Nutrition are there for the taking but since these entail crafting a correct macronutrient plan and computing macros which will be aligned to your lifestyle and fitness goals, I highly recommend that you consult me and my team to avoid reversing whatever progress that you have already made by committing mistakes such as these.


If you complete the application on the link below you can book in your discovery call to discuss your journey!

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  1. Kevin Hall, et. al (2012). Energy balance and its components: implications for body weight regulation. The American Journal of Clinical Nutrition. 95(4): 989–994. doi: 10.3945/ajcn.112.036350


  1. Ann-Marie Ravn, et.al (2013). Thermic effect of a meal and appetite in adults: an individual participant data meta-analysis of meal-test trials. Food and Nutrition Research. 57: 10.3402/fnr.v57i0.19676. doi: 10.3402/fnr.v57i0.19676









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