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Calories - What's the Right Amount for Me?

In this blog, I'll discuss why calories are important, energy balance, how to accurately estimate and adjust caloric intake for you goals and tools you can use along the way

Contrary to what some might have you believe, calories are not little monsters that live in your wardrobe and sew your clothes a little tighter every night. In fact, there’s nothing scary about them at all!

The scientific definition of a calorie is “the energy needed to raise the temperature of 1 gram of water by 1 °C”. To put it simply calories are just units of energy. They provide the energy the body requires for growth, metabolism and other bodily functions. This occurs via complex metabolic processes involving various enzymes and hormones. Foods that contain calories are required in large amounts and so are called “Macronutrients” (carbohydrates, fat, protein and alcohol), we'll learn more about those in another blog coming soon 


Why are calories important?

Nutrition can be a very confusing topic. For every expert that preaches the benefits of a high protein, low fat diet with high intake of fruit between the hours of 9 and 4 there is another who believes the opposite. Those who do not understand the basic principles of nutrition may find selecting a dietary approach very confusing. But there is one key factor that governs every single diet that we can all appreciate and it has the biggest influence on dietary success’s and failures and is highly specific to you. Energy Balance

If you learn one skill and understand how to implement it into your dietary intake through these blogs, make sure it's this one!


What is energy balance?

Energy balance occurs when your energy intake - food and drinks - perfectly matches your energy expenditure - physical activity and basal metabolism, essentially where you’re consuming just the right amount of energy for your expenditure

Energy balance has the biggest influence on dietary success and should be the number one priority when setting up a nutrition programme


What is energy intake and expenditure?

Energy intake refers to anything we consume that contains energy in the form of calories. This is influenced on a daily basis by intake of:

  • Food
  • Beverages (including alcohol)
  • Certain medicines

Energy expenditure refers to anything we do that expends energy in the form of calories. This is affected by some factors that can be easily altered such as physical activity and some that cannot be altered with ease such as thermal regulation and basal metabolism


What is negative energy balance?

Negative energy balance occurs when energy intake is lower than energy expenditure

This may be a result from restricted intake, increased physical activity or a combination of both and in practice the latter appears the most effective

The result is an energy deficit that the body must overcome in order to function. The body utilizes stored energy in the form of glycogen, fat & muscle tissue to supply the required energy.

The breakdown of bodily tissue in this manner results in weight loss and in healthy individuals negative energy balance ALWAYS results in weight loss!

What is positive energy balance?

Positive energy balance occurs when energy intake is higher than energy expenditure

This may result from increased intake or decreased physical activity. More often than not it is a combination of both. This creates an energy surplus with the excess energy being stored as fat, muscle or glycogen

This increases body tissue mass and so results in weight gain.  In healthy individuals positive energy balance ALWAYS results in weight gain!


How can you estimate your energy balance?

Consuming the correct energy requirements for you and your goals is an essential component of any diet. Whilst it is very difficult to definitively calculate your energy requirements there are a number of tools available to make an accurate estimate including 

  • The Mifflin-St Joer Equation 
  • Bodystat Testing

There are other methods available, but these two are my favourites and LED members have access to both of the these

The Mifflin-St Joer Equation

So okay its a scarey kinda name and is a little tricky initally to get your head around - but bear with me - its worth it!

The equation is a relatively simple method to estimate the energy intake required to achieve energy balance and takes in to account both your basal metabolic rate and physical activity

Energy Requirements = BMR x Physical Activity

BMR - Basal Metabolic Rate

  • Male BMR: (10 * weight (kg)) + (6.25 * height (cm)) – (5 x age (years)) + 5
  • Female BMR: (10 * weight (kg)) + (6.25 * height (cm)) – (5 x age (years)) - 161

Physical Activity

  • Sedentary - BMR x 1.2
  • Lightly Active - light exercise or sports 1-3 days a week: BMR x 1.375
  • Moderately Active - moderate exercise or sports 3 - 5 days a week: BMR x 1.55
  • Very Active - hard exercise or sports 6 - 7 days a week: BMR x 1.725
  • Extremely Active - very hard exercise, sports or training twice a day: BMR x 1.9

So, let's use me as a working example - eeek!

Gender: Male

Weight: 87.2kg

Height: 180cm

Age: 23 years

My BMR = ((10 * 87.2) + (6.25 *180) – (5*23)) + 5

                = ((872) + (1125) – (115)) +5

                = (1882) + 5

                = 1887

So, acccording to the Mifflin-St Joer Equation my BMR is equivalent to 1887 calories. Now I need to adjust for my physical activity levels and this requires objective thinking to avoid under or over estimations, a member of gym team can help you with this. I've analysed my fitness routine and characterize myself as ‘Very Active’ and as a result I multiply my BMR by 1.725

Energy Requirements = BMR * Activity

                                    = 1887 * 1.725

                                    = 3255

Therefore the Mifflin-St Joer Equation estimates that in order to achieve energy balance I need to consume 3255 calories

The Bodystat Test

If you’re put off by all the numbers or maybe you don’t fancy getting a calculator out then fear not, Bodystat Testing is another means of estimating energy requirements that is very simple. LED Unlimited members can book a Bodystat test at any of our 10 LED gyms.  If you're not an LED Unlimited member  - goodness me why ever not? - then you're more than welcome to book and pay for a test for around £12

The Bodystat Test uses similar principles by calculating your BMR and also accounts for your physical activity levels. The Bodystat Test however, is able to go in to much more detail and can estimate body fat percentage and lean body mass. Since we know lean tissue or muscle is more metabolically active and requires more calories compared with body fat, we can be sure that estimates from a bodystat test are very accurate

The test can can take anywhere between 15 and 30 minutes.  It's advisable to make sure you don't eat, drink caffiene or sugary drinks and avoid exercise for at least two hours before the test.  You'll lie down and two small sticky pads are attached to one of your hands and feet and then you'll be connected up to the Bodystat machine for it to take your readings

The gym team will then be able to go through your results with you and give you a record to keep.  It's worth bering in mind that if you book in for a follow-up test to measure your progress that it's a good idea to have it done at a similar time of day


How do I adjust my energy balance to help my goals?

So far we have discussed how to estimate your energy requirements to achieve energy balance but we have not discussed the effect of such intake. If you were to achieve energy balance every day you would not gain any weight or lose any weight you would simply maintain your weight.

Whilst some of you may wish to maintain your current body weight and focusing on improving strength, cardiovascular performance or flexibility, the majority are likely to fall into one of two extremes.

The first is those who want to lose body fat and the second being those who want to increase their lean body mass. Below I will outline how to adjust your energy intake to lose 1lb a week and gain 1/2lb a week based on this principle

1lb of human body fat = ~3500 calories

3500 / 7 days = 500kcal

Energy balance for fat loss

Whilst aiming to lose 1lb a week may not seem significant, such an approach ensures any weight lost is fat and not lean mass compared with losing higher amounts

In order to lose 1lb of body fat a week we need to create an energy DEFICIT of 3,500 calories per week. As there are 7 days in a week we need to create a deficit of 500 calories on a daily basis

A simple way of creating this energy deficit is to subtract 500 calories from your estimated energy expenditure number, by increasing physical activity exclusively or combining the two

Energy balance to increase lean body mass

In order to gain 1/2lb a week we need to create an energy SURPLUS of 1750 calories per week

Aiming to gain more than this will likely result in excess fat accumulation not increased muscle

Since there are 7 days in a week we must create a surplus of 250 calories on a daily basis. The best method of achieving this is to add 250 calories to your estimated energy expenditure number.  Of course this could also be achieved by reducing physical activity but this would be counter-productive for those aiming to improve muscle size


So yes, this is a meaty blog - or a veggie one if that's more appropriate - but there has been a lot to cover off! Hopefully, after reading this you have a clearer idea of how to estimate your energy requirements and adjusting intake based on your goals. It's been a long read but as I have said your caloric intake has a HUGE influence on your dietary success and so it is crucial you consume the right amounts to achieve your goals

If you have any further questions or would like to book a nutrition consultation with one of the team please contact us on or feel free to call me on 01404 814317

Buen provecho!