Let's talk About Calories
The following excerpt is taken from my latest creation, Nutrition Fundamentals For An Aspiring Athlete, the first ebook i’ve ever published. This book tackles the subjects involved with using nutrition to Optimise recovery, fuel athletic performance and maximise progress in physical training. Although it’s targeted towards the aspiring athletes of the world i’m certain that the majority of people who read it, no matter what your general activity levels may be, will gain some useful knowledge surrounding nutrition, health and wellbeing.
By the end of this book my hope is that you have a clear idea on how you can use nutrition to optimise your unique lifestyle and fuel your body for the specific set of challenges you consistently put it through. But to arrive at that destination we have to start at the beginning. We first must understand the fundamental aspects of what nutrition is before we can get into the discussion on how you can change your dietary choices to create a positive impact on your life. So let’s begin at the ground floor, Calories.
ENERGY INTAKE IS REQUIRED FOR SURVIVAL, but the quality and quantity of the energy you consistently consume is hugely impactful to your bodyweight, energy levels, performance, recovery and general health and wellbeing.
Calories are often spoken about as something to avoid or restrict, but at their most basic level, a calorie is simply a unit of energy. More specifically, a calorie measures the amount of energy that food provides to the body. This energy is released when food is broken down and used to fuel every process that keeps you alive and physically capable.
In nutrition, calories represent the energy content of food and drinks. When you eat, your body converts that energy into forms it can use to support basic bodily functions, movement, recovery, and adaptation to physical activity. Without a consistent supply of energy, your body cannot function optimally, regardless of how motivated you may be. Calories are literally the fuel that keeps your body functioning.
Even at complete rest, your body is constantly using energy. Breathing, circulating blood, regulating body temperature, digesting food, and maintaining brain and nervous system function all require calories. This baseline energy requirement is known as your BASAL METABOLIC RATE (BMR), and, interestingly, accounts for the largest portion of daily calorie use for most people.
BASAL METABOLIC RATE
In simple terms, your Basal Metabolic Rate is the number of calories your body would require in a 24-hour period if you were to do nothing more than lie still and rest. Factors such as body size, muscle mass, age, sex, and genetics all influence BMR and, generally speaking, bigger individuals with more lean muscle mass tend to have a higher BMR than smaller individuals with less muscle mass. An interesting fact there, that I don’t want to gloss over… muscle tissue requires more energy to maintain than fat tissue. Take a moment to let that sink in:
Muscle tissue requires MORE energy to maintain than fat tissue. Essentially, maintaining a lean physique actually becomes easier if you develop more muscle mass, as additional energy is required to maintain this extra muscle in your body.
While BMR cannot be measured precisely without specialised equipment, it can be estimated using predictive equations. One commonly used method is the Mifflin-St Jeor equation, which takes into account body weight, height, age, and sex to provide an approximate daily energy requirement at rest. Many reputable online calculators use this equation to give a practical estimation of BMR. Below are a couple of links to calculate your own BMR:
https://www.calculator.net/bmr-calculator.html
https://www.garnethealth.org/news/basal-metabolic-rate-calculator
It’s important to remember that BMR is only a starting point. It does not account for daily movement, physical activity, or structured exercise. However, understanding BMR helps provide context for how much energy your body requires before activity is even considered, and why adequate calorie intake is essential even on rest days.
For physically active individuals, calorie needs obviously increase further. In addition to the energy required during the exercise session itself, calories are also needed after activity to support muscle repair, nervous system recovery, and overall adaptation.
ENERGY BALANCE
When calorie intake is matched to your body’s energy demands, bodyweight tends to remain relatively stable over time. This state is known as energy balance, where the energy coming in from food closely aligns with the energy being used through basic bodily functions, daily movement, and physical activity.
Over weeks and months, the interaction between lifestyle, activity levels, and habitual calorie intake creates a natural settling point for bodyweight and body composition. I’m sure you’ve heard the old saying, ‘you are what you eat’. It’s honestly pretty spot-on in this context regarding calorie intake. If I were to look at your lifestyle, activity levels and body composition, then take a look at your calorie intake (the amount of energy you’re regularly consuming) it will nearly ALWAYS be perfectly aligned, meaning that the mirror never lies.
Your body is a very accurate representation of what you put in it and how you use it (on a consistent basis).
If your bodyweight has settled at a certain level for a while now, take a second to go and look in the mirror. This is the result of the amount of energy that you’re consuming consistently matched with your body’s energy demands. Are you happy with your body? Are you happy with the number on the scale? More importantly though, are you happy with HOW you feel and how you perform?
Your settling point is not fixed though, and can shift as lifestyle factors change. Increases or decreases in activity, training volume, work demands, stress, and sleep all influence energy demands. Understanding this relationship helps to explain why long-term weight management is less about short-term restriction and more about finding an intake that supports both lifestyle AND physical demands.
The good news is that you can change your bodyweight and body composition by manipulating these levers. You always have the ability to increase or decrease your energy intake and you also have the power to manipulate your energy output by exercising more or less. Adjusting either of these levers (energy intake and energy output) will result in gradual changes to your physique, including weight and composition changes.
UNDER CONSUMING (CALORIE DEFICIT)
When calorie intake is lower than your bodies overall energy requirements, your body begins to prioritise survival over performance. Energy is diverted away from recovery, strength development, and tissue repair, and instead body tissue, such as fat and muscle, is broken down by your body to keep itself alive and functioning. This is how weight loss occurs, and periodically reducing calorie intake is the catalyst for burning fat and becoming leaner, but problems arise when energy consumption remains too low for too long, as your body doesn’t have the required amount of energy it needs to function properly. Over time this can result in persistent fatigue, reduced endurance, slower recovery between sessions, decreased motivation, and a decline in performance. Being active does not protect you from the negative effects of chronic under-fuelling.
I battled for a number of years, in my early twenties, with under-fuelling due to a condition known as body dysmorphia, and it was horrible. I was constantly getting sick, had no energy to sustain my demanding lifestyle, felt tired all the time. Weak. Frail. I developed some serious deficiencies in my body and when I finally had my blood analysed by a specialist I was told my immune system was on the brink of shutting down. I was told that this was all due to chronically under-consuming food. Deep down I already knew this to be the case, I was just too hyper-fixated on being as lean as possible and had grown to have a very skewed vision of myself when I looked in the mirror. I thought I was doing the right thing by restricting my food consumption as much as possible, I was receiving great compliments from everyone about being ‘shredded’ and ‘diced’, but I was literally dying a slow death. This entire chapter of my life taught me about the importance of energy intake and finding the perfect SETTLING POINT to fuel my lifestyle, recover adequately, look good, and most importantly: FEEL good. Without under-consuming food, but also without over-consuming, which also comes with risks.
A photo of me, at my lightest bodyweight as an adult. 54kg. Training like a maniac. Energy non-existent. My health, especially hormonal health, absolutely cooked. Although it upsets me to look back and see how hard I struggled for these years, I still feel very grateful for the lessons learned along the way.
OVER CONSUMING (CALORIE SURPLUS)
On the other end of the spectrum, consistently consuming more calories than your body requires leads to the storage of excess energy, primarily as body fat. While some fat storage is normal and essential, excessive accumulation over time can negatively impact both health and physical performance. Carrying excess bodyweight places greater stress on joints and connective tissue, and can reduce efficiency during physical activity. This may show up as exercise feeling harder, quicker fatigue, and reduced speed and agility.
From a health perspective, long-term excess bodyweight is associated with an increased risk of conditions such as cardiovascular disease, type 2 diabetes, joint degeneration, and metabolic dysfunction.
While I have personally never struggled with over-consuming calories, all I have to do is look around me to notice how prevalent it has become in society. 66-68% of Australian adults are overweight and ~32% are obese. It’s even worse in America. WHO (World Health Organisation), in 1997, formally recognised obesity as a global epidemic by listing obesity as a major public health problem. And it’s only getting worse.
So… under-consuming calories has devastating effects on an individuals health and well-being, but so does over-consuming, and judging by my eyeballs when I look around at people in society it seems that, as a society, we LOVE eating. I totally get it too, eating highly palatable foods is a very enjoyable experience, and it takes will-power to stop yourself from devouring the whole packet of crisps. Food brands spend BILLIONS of dollars on developing foods with the right amount of fat and sugar that will make you want to eat as much as possible ALL THE TIME. They want your money, they don’t care about your health. I’m not saying that you can’t allow yourself to ever enjoy an occasional treat, but if the majority of your diet comes from highly processed, calorie dense foods, and you also believe your body weight to be higher than you would like, then an easy place to begin your weight-loss journey would be cutting down on junk food, but more on that later in this book.
ESTIMATED ENERGY REQUIREMENTS (EER)
Consuming an appropriate amount of calories allows your body to meet its basic needs, support physical activity, and recover effectively without excessive energy storage. When calorie intake is aligned with lifestyle and activity levels, the body is better able to perform, adapt, and maintain a healthy bodyweight over time.
This concept is often described as an individuals Estimated Energy Requirements (EER).
EER refers to the approximate number of calories a person needs each day to support basic bodily functions, daily movement, and physical activity while maintaining bodyweight. Unlike BMR, which calculates energy needs at complete rest, EER accounts for lifestyle and activity levels, making it a more practical reference for everyday living.
EER is typically estimated by starting with an individual’s BMR and then adjusting for activity level. This is often done using activity multipliers that reflect how active a person is across the day and week. For example, someone with a physically demanding job or who trains intensely, multiple times per week will generally have higher energy requirements than someone who is mostly sedentary. While these calculations are not exact, they provide a useful starting point for understanding how much energy your body requires to function, perform, and recover effectively.
Below are a couple of links to calculate your own EER:
https://www.omnicalculator.com/health/eer-estimated-energy-requirement
https://calculator-online.net/eer-calculator/
It is important to view EER as a range, rather than a fixed number. Daily energy needs fluctuate based on training intensity, session duration, recovery demands, stress, and sleep. As a result, estimating EER is best used as a guide rather than a strict target. So remember not to get too caught up in these calculations of BMR and EER, and instead use them as very general ball-park estimations.
COUNTING CALORIES
Counting calories can be a useful tool when it is used with the right intention. Rather than viewing calorie tracking as something that must be done indefinitely, it can be helpful to approach it as a short-term learning exercise. Tracking food intake for a period of around two weeks allows you to gain a clearer understanding of your current eating habits and typical daily energy intake.
During this time, calorie tracking helps highlight how much energy is being consumed on an average day, rather than what is perceived to be eaten. Many people underestimate or overestimate their intake, particularly when eating out, snacking, or consuming calorie-dense foods. Logging intake provides objective feedback and helps bridge the gap between perception and reality.
Tracking calories also increases awareness of calorie density, which refers to the amount of energy a food provides, relative to its volume or weight. Some foods contain a large number of calories in a relatively small portion, while others provide fewer calories for a greater volume of food. Understanding this concept can help you make more informed food choices without needing to label foods as good or bad.
A short period of calorie tracking can also help identify patterns such as:
Large differences between weekday and weekend intake
Frequent high-calorie snacks or drinks
Meals that are low in protein or fibre and less satisfying
Portion sizes that may be larger or smaller than expected
For many people, extended tracking can become mentally fatiguing or interfere with the enjoyment of food. Once a clear understanding of intake and food choices has been established, you can begin to transition away from tracking and rely more on structured meals, portion awareness, and hunger cues.
When used briefly and purposefully, calorie tracking is a learning tool, not a measure of discipline or success. Its value lies in increasing awareness and understanding, allowing you to make adjustments that better support bodyweight management, energy levels, and physical performance without ongoing restriction or obsession.
The biggest piece of advice I have for you before you begin tracking your own calories is to not get caught up on restricting your calorie intake as much as you possibly can. That’s not the intention behind this exercise at all. The intention is to develop an understanding of the calorie density in the foods that you regularly consume, so that once you establish a range of calories you wish to commit to (in order to reach your body weight goals) you have a way better idea of what foods to eat depending on what your goal is (Gaining weight or losing weight).
The Calorie tracker that I have always used, which is also one of the most popular apps of its kind in the world, is called ‘My Fitness Pal’ which you can easily find in the App Store on Apple and Android devices. If you commit to tracking calories, it’s important to include absolutely everything that you swallow. Don’t leave out snacks, sauces, oil used for cooking, or anything else. You’ll be surprised how quickly calories add up! Here is a link to the app for any Apple users:
https://apps.apple.com/us/app/myfitnesspal-calorie-counter/id341232718
ADJUSTING CALORIES FOR WEIGHT CHANGE
Ok, so here’s where you can now actually decide to make changes to your diet to achieve your bodyweight goals. Once you have a reasonable estimate of your daily calorie intake that maintains bodyweight (EER), changes in bodyweight can be influenced by making small, consistent adjustments to that intake over time. The key word here is small. Large or extreme changes may produce rapid weight fluctuations, but they are far less reliable and often compromise health, performance, and long-term adherence.
LOSING WEIGHT
For healthy, sustainable weight loss, a moderate calorie reduction is almost always more effective than aggressive restriction, and this is mostly due to the individual having a way easier time adhering to the dietary changes. A reduction of approximately 300–500 calories per day from maintenance intake is considered to be the best place to start a weight loss phase for most individuals. This size of adjustment is typically sufficient to create gradual weight loss while still providing enough energy to support daily function, physical activity, and recovery, without having to endure horrible feelings of starvation and no energy.
Smaller calorie deficits also tend to:
Preserve lean muscle mass
Support training and performance
Reduce excessive hunger and fatigue
Improve long-term consistency
Weight loss at this pace is often slower, but it is more reliable and easier to maintain over time.
GAINING WEIGHT
For those aiming to gain weight or increase lean mass, a modest calorie increase is also recommended. An increase of approximately 200–400 calories per day above maintenance intake is often sufficient to support gradual weight gain without excessive fat accumulation.
Small increases in daily calorie consumption allow the body to:
Adapt to higher energy intake
Support training adaptations
Minimise unnecessary fat gain
Assist in building lean muscle mass
As with weight loss, faster is not better. Large calorie surpluses will lead to rapid weight gain, but much of this gain is often unwanted body fat rather than lean muscle tissue. So whatever your body weight goal is, remember that slow-and-steady is the way to go!
THE TAKE-AWAYS
Let’s quickly touch on the key take-aways surrounding calories and energy intake:
Bodyweight does not respond instantly to calorie changes. This is important to understand. If you eat a giant dinner you’re not going to wake up with 1kg of additional fat that’s been created through the night, even if the scales tell you that you’ve gained 1kg. And if you fast for 24 hours and see that the scales tell you that you’re 2kg lighter than the previous day, you haven’t magically incinerated 2kg of fat through the night either.
True change to body weight occurs through consistent patterns over weeks and months, not individual days. Small, steady adjustments that are adhered to are where the magic really happens. Smaller dietary and lifestyle changes are also easier to sustain, so it’s a win-win. You just have to get over the fact that reaching your desired bodyweight is probably going to take a bit longer than you want it to.
Another important side-note is to recognise that calorie needs are not static. Changes in training volume, daily movement, work demands, sleep, and stress can all influence energy requirements. If you’ve decided that you’re going to consume 2,300 calories per day but then happen to go surfing for 8 hours on a certain day, your body will require more energy to recover, due so much energy output. For this reason, calorie and dietary adjustments should be viewed as starting points, with further changes made gradually based on how your body responds over time and also taking into consideration days of intense energy output and days of less-than-usual movement.
A practical and reliable approach to weight management focuses less on precision and more on consistency. By making moderate adjustments to daily intake and allowing time for your body to respond, you are more likely to achieve changes in bodyweight while maintaining performance, health, and enjoyment of physical activity.
Calories, then, are neither good nor bad. They are simply energy. A resource that must be supplied in the right amount to support both health AND performance.
MY OUTLOOK ON CALORIES
The way I view calories personally, is that I have a budget (or allowance) of calories each day that I can spend on whatever foods I like, and the exact allowance that I set depends on my current bodyweight goals.
Once I have set a goal regarding my bodyweight (maybe I want to gain 2kg of muscle mass, or maybe I want to cut 1kg leading into Summer to look extra shredded) I Count calories for 2 weeks to get an idea of how much energy I’m consuming on a regular basis.
From there, having evidence of what my average daily calorie consumption is, I will choose my new ‘daily calorie budget’ to abide by. It’ll either be an additional 200-400cals per day if I wish to gain weight, or it’ll be a reduction of 300-500cals per day if I wish to lose weight
But there’s more to nutrition than just counting calories…
To understand how to manage calorie intake effectively, it is important to first understand where calories come from and how different types of food affect the body in different ways.
In the next chapters, we’ll break down the three macronutrients: protein, carbohydrates, and fats, and explore how each contributes to energy intake, recovery, bodyweight, and physical performance.
Thanks for reading Chapter 1 (of 10) from my Ebook! If you’re keen to read the rest of the book you can find it in my online store by clicking the link below. For anyone who purchases it, thank you! You’re support is is always appreciated.