I’m a nutrition coach and it never ceases to amaze me how little people understand energy balance. I have explained this in some previous blogs like this one (HERE) or this one (HERE). I have also done numerous videos on this topic, one of which you can see lower down this article. So, to help you stop pissing in the wind here is a brief introduction to how Calories work and how to estimate and track your Calories.
24-hour energy balance.
Calories are merely a measurement of energy, like millimetres are a measurement of length. So, let’s not get all hung up on the minor details here. Calories, or kcals, measure the amount of energy you get from the food you eat and how much energy you burn during daily activity and exercise.
We measure this over the 24-hour period, not one meal at a time or one workout at a time. But, we also need to look at this mechanism over the week. So, it doesn’t necessarily matter if you go over on your kcals one day, so long as you are under for the rest of the week (assuming fat loss is your goal). In fact, you can look at energy balance over a month, treat it like a bank balance, all the deposits and withdrawals you make will determine how much money (Calories) you have left at the end of the month.
As pointed out on those previous blogs I mentioned there is a compelling body of evidence that shows us Calories in vs Calories out matters – A LOT – it doesn’t matter what a nutritional therapist, holistic lifestyle coach or naturopath tells you, physics DOES matter. All diets work because they are designed to create an energy deficit. The methods they use are a set of rules that control the volume of food you consume. Some of these methods are healthy and sustainable and some aren’t. Special mention to Slimming World here. Food is food, it’s not a sin (or syn) please stop teaching people to have a disordered attitude to food.
The Calorie Equation
Just before I show you a simple predicative equation to estimate your kcals let me just say that this isn’t an exact science, the clue is in the name – PREDICTIVE – these equations will estimate your energy balance based on a number of factors. These factors are largely averages so your actual kcals may vary by about 5 to 15% either side of that number, so don’t be too rigid in your thinking here. Track your body composition and weight over a couple of weeks, but also track your exercise performance, your sleep and your overall sense of wellbeing. If everything looks and feels good then there’s no need to change, if things aren’t going according to plan you may have to increase or decrease by around 5% or so and then reassess until you get things right.
Yep, it could take a little while to get it right but it’s worth it in the end. To work out your resting metabolic rate use the following equation:
Bodyweight in kg x24 (or lbs x11) for a male or 22 (or lbs x10) for a female.
Then multiply by a physical activity ratio (PAR).
- Sedentary x1.2 (very little movement or exercise)
- Light activity x1.375 (maybe 6-8,000 steps per day or 1-2 exercise sessions per week)
- Moderate activity x1.55 (8-10,000 steps per day plus 3-4 exercise sessions per week or have a very active job)
- Heavy activity x1.725 (Very active job plus 3-4 workouts per week or 10k+ steps and 5+ weekly workouts)
At this point I should mention that most people will instinctively over estimate the amount of activity they do, and this might be where your kcal prediction falls down, your RMR is probably pretty spot on, and I have come to find that part mostly reliable when doing similar equations on my clients. But almost everyone is less active than they think and trains well within themselves.
Using myself as an example the calculation will look like this:
76kg x 24 = 1,824 kcals RMR – this is my resting metabolism, all the kcals I need to function at the most basic level; breathing, circulation, hormone secretion, gene express, etc.
Because I train 5 days per week with 3 hard days and 2 lighter mobility-based days and get around 8,000 steps per day I am going to say I am moderately active. Therefore, I multiply my RMR by 1.55.
1,824 x 1.55 = 2,827 kcals
This is my predicted maintenance Calories or total daily energy expenditure (TDEE). If I ate 2,800kcals per day for the rest of my life, assuming my activity didn’t change, I shouldn’t gain any fat. But, if I wanted to lose some fat I would need to create an energy deficit.
(I know from experience that this estimated number is pretty close and I have previously ate as much as 2,600 kcals per day while still losing fat)
I like to use percentages with my clients to create the deficit.
- -5-10% for active people with only a small amount of fat to lose
- -15-20% (or 500kcals) for less active people or anyone with more than a few lbs of fat to lose
- -25-30% for very obese individuals who need to lose weight more rapidly
It’s worth noting that the bigger the deficit, the faster the weight loss and the more of that weight will be from water and lean body mass which isn’t ideal. You want to maintain as much lean mass as possible while dieting. There are three things you can do to ameliorate this process.
- A smaller deficit with slower fat loss
- Eat significant amounts of protein (1.6-2.2g per kg)
- Do resistance training with the aim of ‘building’ muscle
Again, the two articles I linked to at the beginning explain this in more detail and with more references to back up the rationale.
Watch this video to see me explain the calorie equations in a bit more depth.
For weight management it’s important to understand how energy balance works and it’s important to track this consistently. Eventually you may come away from meticulously tracking kcals all the time and adopt a more intuitive approach to eating. You don’t even HAVE to count Calories so long as you control portion sizes, it’s just that counting Calories is more measurable and more accurate. It’s important to learn how to weigh and track everything you eat if you are to avoid under reporting. Anyone who thinks they are eating 1,000kcals and NOT losing weight is 100% eating a LOT more than 1,000kcals per day.
I’ll let this infographic that I made with my remedial levels of Canva design expertise sum it all up for you.
Let me just finish by saying, trust the numbers, they aren’t far off and if you think it’s too much but you are overweight you can guarantee that you have been pretty consistently eating over that for some time already, so it’s not the numbers that are wrong, it’s your perception of the energy value of the food you eat. Don’t forget that liquid Calories count too, especially alcohol… Sorry about that.
Lastly, if you have been struggling to achieve your fitness goals don’t get frustrated, that’s why coaches like myself exist so if you want help reach out to an expert to help you, just like you would if your car breaks down on the M1.
If you are a man over 35 and you want to get a kick up the arse to get your nutrition, training and mindset back on track I have a FREE 7-day e-course for just that purpose ==>CLICK HERE