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Determining Caloric Needs For Any Transformation

calorie intake

The most important factor determining success when it comes to weight loss is the amount of calories you consume. Undoubtedly, you’ve heard this over and over before, but it’s imperative that you understand the implications of such a claim.

If you think about weight loss in the context of what our bodies are and what weight loss means, it begins to make sense. We are a compilation of different tissues, which all have caloric values. It then stands to reason that an effective way of reducing the amount of calories we carry around each day is to first, burn off existing calories and second, limit the amount of calories being reintroduced.

Understanding this allows you to know that it’s not just the types of foods you’re eating, but rather, the amount of calories you’re ingesting through that food. You can then adjust, based on your goals.

Here are a few ways that you can determine your own needs for your best body.

Different Methods Of Finding Calorie Requirements

The most convenient and fastest way to determine your caloric needs is to use a verified formula. Many times, these formulas, which can be found throughout the Internet, take many factors into account when providing you with your daily caloric needs.

When choosing a formula to use, you need to determine the level of complexity you desire. You have the ability to simply use your bodyweight and activity as a metric, or you can get more intricate using formulas that require height, age, gender, activity level and desired goal.

Mifflin St. Jeor

The Mifflin St. Jeor formula is considered to be the gold standard of formulas for determining resting metabolic rate and then the overall requirements you need to account for activity. Essentially, you determine your resting metabolic rate, or the number of calories required for your body to survive, and then adjust based on how active you are (1).

Men: 10 x weight (kg) + 6.25 x height (cm) – 5 x age + 5

Women: 10 x weight (kg) + 6.25 x height (cm) – 5 x age -161

Using an example female that weighs 160 lbs., 5 feet, 5 inches tall & 40 years old:

  • 10 x 70 kg = 700
  • 25 x 165 cm = 1031.25
  • 5 x 40 = 200 – 161 = 39

700 + 1031.25 – 39 = 1692.25 calories (RMR) 

What this number means is that for a 160lb. female, who is 5 feet, 5 inches tall and 40 years old, is estimated to require 1692.25 calories daily to survive and maintain her body. But you need to go a step further to account for activity level. Upon finding the above number for your situation, you then need to multiply the end number by one of the following:

  • Sedentary / Desk job: 1.2
  • Standing Work / Up Regularly: 1.4
  • Active through work or exercise: 1.6
  • Very Active / Exercise 6 + times per week: 1.8+ (2).

For instance, with the above example, if this person is active through work or exercise, they might choose around 1.5. When added to the equation, we find the following number: 

1692.25 x 1.5 = 2538 calories 

This number then provides an estimate of your maintenance calories. This is the amount of calories you can consume each day and expect that your bodyweight will neither increase nor decrease.

Track Intake & Bodyweight Changes (Recommended)

The second option you have, while a bit more difficult and intrusive, is a much more accurate depiction of your true maintenance.

To achieve this, you’ll need to track both your calorie intake as well as your bodyweight changes for a period of 5 to 7 days. By doing this, you not only gain an understanding of just how much you’re eating, but also an accurate depiction of how your calorie intake influences your body.

What this means in reality is that you can have 1 of 3 bodyweight changes as a result of tracking, which then points you in a definitive direction, based on your goals.

  1. Bodyweight stayed similar, within 1 pound: You’ve found your maintenance.
  2. Bodyweight increased by more than 1 pound: You consumed more than your maintenance.
  3. Bodyweight reduced by more than 1 pound: You consumed fewer calories than normal.

As you can see, by tracking, you gain a more realistic understanding of how much you’re eating and how that compares to your normal intake. By simply observing body weight changes and acting as normal, you gain an understanding of what you really need.

calorie intake

Adjusting After You’ve Found Your Caloric Needs

Finally, once you’ve determined within reason your typical caloric needs, you can then adjust this number based on your goals.


If you’re hoping to simply maintain your current bodyweight or even hope to improve muscle and performance, sticking with your normal maintenance calories is a good idea. Doing so allows for enough energy for recovery and for your workouts, but you don’t risk accidentally overconsuming and gaining weight.

Muscle Growth Or Increase

If you want to put on muscle or increase your bodyweight, try increasing your maintenance calories anywhere from 5-10%. Anything more than this and you risk gaining unwanted body fat. Using the example above:

2538 calories x .05 = 127 calories: 2538 +127 = 2665 calories 

Weight Loss

To lose weight you need to reduce calories. A good starting point is a 15-20% decrease from maintenance. 

2538 calories x .15 = 381 calories: 2538 – 381 = 2157 calories

calorie intake

Remember Requirements Change

Lastly, remember that, over time, your requirements will change. If your goal is weight loss, eventually your body will adapt and require that you reduce calories further. The same goes for maintenance and muscle growth.

Consider re-doing this process every once in a while to ensure consistent and efficient progress.



  1. Mifflin, M. D., St Jeor, S. T., Hill, L. A., Scott, B. J., Daugherty, S. A., & Koh, Y. O. (1990). A new predictive equation for resting energy expenditure in healthy individuals. The American journal of clinical nutrition51(2), 241-247.
  2. Black, A. E., Coward, W. A., Cole, T. J., & Prentice, A. M. (1996). Human energy expenditure in affluent societies: an analysis of 574 doubly-labelled water measurements. European journal of clinical nutrition50(2), 72-92.



About the author

Rudy Mawer, MSc, CISSN

Rudy has a 1st class BSc in Exercise, Nutrition & Health and a Masters in Exercise & Nutrition Science from the University of Tampa. Rudy currently works as a Human Performance Researcher, Sports Nutritionist and Physique Coach. Over 7 years he has helped over 500 people around the world achieve long last physique transformations.

He now works closely with a variety of professional athletes and teams, including the NBA, USA Athletics, World Triathlon Gold Medalists, Hollywood Celebrities and IFBB Pro Bodybuilders. If you would like to get in contact or work with Rudy please contact him on social media.

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