Energy Balance Series, Part 2: Energy Expenditure

Hi lovely,

Welcome back to the Energy Balance series!

In the first installment, we have explored the basic concept of energy balance and discussed how small, sustainable changes can make a big difference when reaching your goal and achieving an optimal relationship between energy intake and output:

The energy intake part of the equation is fairly straightforward - it consists of the calories you get from food. Manipulating food intake is one of the primary strategies for achieving optimal energy balance - however, it’s certainly not the only tool available at your disposal!

For example, if your goal is fat loss, the most obvious thing to do initially is to cut back on calories. However, this alone is not a sustainable long-term strategy. Over time, with no other changes implemented, your body will adapt to the reduced intake, and you’ll stop seeing results. Our bodies are smart machines that are exceptionally good at adapting - in this example, your metabolism will slow down to preserve as much energy as possible, and you will start burning fewer calories. If you keep cutting your intake, you will eventually find yourself in a very unsustainable situation of consuming extremely little, feeling depleted - and yet not progressing with your goal due to metabolic adaptation occuring. 

So, is there a solution? Sure is, gorgeous lady!

Today, we would like to talk about energy output in more detail - including factors that contribute to it, and how you can manipulate them to your advantage!

Energy expenditure: overview

There are several components of energy expenditure, and each has the potential to be tweaked for optimal outcomes:

  • Resting energy expenditure (REE) is also referred to as your basal (“basic”) metabolic rate (BMR)
  • Non-resting energy expenditure (NREE) includes energy output from food consumption and digestion, as well as your daily activities

Let’s have a closer look at each of these!

Resting energy expenditure

First up, resting energy expenditure - or basal metabolic rate, in other words.

To put it simply, BMR is the amount of energy required to keep your body functioning at rest. We don’t consider this often, but basic bodily functions such as breathing, pumping blood and maintaining correct body temperature require A LOT of energy!

In fact, approximately 70% of your total energy output goes into keeping your body running. 

Your gender, age, height and body composition are some of the primary factors that influence your BMR. While most of them are non-modifiable, you can certainly adjust your BMR by altering your body composition.

Look at these 2 photos of Rachel (left - a few years ago; right - current physique) and try to guess which Rachel has a higher REE/BMR:

If you’re thinking “right side” - congratulations, you’re correct!

One of the best ways to boost your BMR is increasing your lean muscle mass, as it’s very metabolically active and requires lots of energy as a result! As a result, even at complete rest Rachel on the right would burn more calories than Rachel on the left.

And of course, in addition to appropriate nutrition, you will have to adhere to an exercise protocol - and the good news is that regular exercise also boosts your resting energy expenditure. According to research, your BMR remains elevated so long as you exercise at least three days a week on a consistent basis, no matter what kind of structured activity you prefer!

Non-resting energy expenditure

We’ve established that REE accounts for ~70% of the total energy expenditure - so what about the remaining 30%?

It’s all divided between the 3 components of non-resting energy expenditure (NREE):

  • Non-exercise activity thermogenesis (NEAT)
  • Exercise activity thermogenesis (EAT)
  • Thermic effect of food (TEF)

This may sound a bit complicated, but each of these components are fairly straightforward to understand! Let’s have a closer look.

Non-exercise activity thermogenesis

Non-exercise activity thermogenesis (NEAT) simply refers to energy you need to perform non-structured physical activity, including:

  • Running errands
  • Performing housework
  • Walking or riding a pushbike to commute
  • Playing with your kids/siblings
  • Being on your feet a lot - unintentionally (e.g. if your job is physically demanding) or intentionally (e.g. setting a daily step goal)
  • And anything else requiring energy - even as trivial as getting up from a seated position!

The main defining factor here is that the activity is “spontaneous”, e.g. wasn’t planned solely for the purpose of exercising.

Manipulating your NEAT is a very simple and effective way to tweak your energy balance.

For instance, someone who is looking to lose fat may wish to increase their activity by walking around more (e.g. walking to the shops instead of driving), spending more time standing vs seating, and decreasing reliance on appliances when doing housework (e.g. manually chopping the veggies instead of using a food processor, or sweeping instead of vacuuming). 

Don’t obsess over these strategies though, and certainly don’t change your lifestyle drastically for the sake of a few calories burned! However, it’s worth remembering that little things do add up, and being a little bit more conscious of them within reason. 

Exercise activity thermogenesis

Exercise activity thermogenesis, or EAT, refers to energy required to perform structured exercise!

Photo: Our ambassador Linda absolutely killing it at one of the recent BBR events!

Structured exercise can burn hundreds of calories at a time, so it’s certainly a powerful variable in the energy balance equation!

To achieve fat loss, you certainly want to stay as active as possible in a sustainable and enjoyable way for you! This could be:

  • Weighted sessions
  • Cardio - being that HIIT or LISS
  • Other types of structured activity such as dancing, rock climbing, etc
  • Or any combination of the above - so long as you enjoy it, push yourself and consistently tick off your planned sessions!

It’s worth noting that building muscle is a bit of a different story, as it’s overall less reliant on energy balance. Conventional wisdom is that you must be in a surplus to gain muscle, however it’s not strictly true. In fact - whether it’s an optimal approach or not - you can make muscle gains while being in maintenance mode or even in a calorie deficit, depending on how you structure your training and nutrition. 

The most important factors for achieving muscle gain include lifting challenging weights, implementing progressive overload and consuming sufficient protein to support muscle growth - and while this may be easier and more efficient in a surplus, it’s not absolutely necessary. 

Thermic effect of food

Thermic effect of food (TEF) is the amount of energy required to process food for use and storage in the body. 

Interestingly, it depends on the macronutrient composition of the food consumed, with protein-rich foods requiring more energy to process. Furthermore, spicy foods have also been shown to increase the TEF, and therefore overall energy expenditure! 

By the way, we have a great Tamari Prawns recipe in the BBR app for those who like it hot, courtesy of our fabulous BBR chef Zoe Lafon:

However, remember that overall, TEF contributes relatively little to your energy output, so certainly don’t alter your nutrition patterns dramatically just for TEF-boosting reasons!


In summary, together with a well-planned nutrition protocol, altering various aspects of your energy expenditure can be a great way to achieve the optimal energy balance for your overall goal!

To remain in a calorie deficit, consider boosting your energy expenditure through being more active both in and out of the gym, exercising regularly and increasing lean muscle mass. Although nutrition is still very important, and you can’t out-perform an unbalanced diet, you simply can’t keep reducing your intake forever - which is why manipulating your energy output is crucial for long-term success. 

A calorie surplus is primarily achieved through nutrition, however strategies such as limiting cardio can contribute significantly and help avoid the need to raise your intake uncomfortably.

And to stay in maintenance, find your happy medium - which can be trickier than it seems, but is still perfectly achievable! 


Hope you enjoyed this blog, and certainly stay tuned for the rest of the series!