How To Determine Your Daily Calorie And Macronutrient Intake Levels

Stop guessing and start calculating. This guide to calorie requirements features numerous BMR equations, and advice on macronutrient breakdown.

The goal of this article is to provide you with guidelines that will help you determine not only how much food to eat per day, but also how to portion your macronutrients:

General terms and their definitions will be covered, along with formulas that can help you get on the right path. Before we hit that information, I want to advise taking a week or two to study your current eating habits. Write down everything you eat, and find out how many calories, and grams of protein, carbs and fats you are eating each day.

This will take some work but you must do it. If you don't understand portions, calories and macronutrient compositions of the foods you are eating, the information contained in the rest of this article won't matter or help.

Calorie Expenditure - From BMR to TDEE

Weight LifterBMR - BMR, or basal metabolic rate, is basically the amount of calories you would require on a daily basis if you didn't move at all and expended the minimal amount of energy. To calculate your BMW, check out the BMR calculator on M&S.

BMR is commonly mistaken for the amount of calories you should eat each day. This is not the case, unless you are bedridden. It is a base level if you have zero activity on a daily basis, and nothing more.

NEAT - NEAT, or non-exercise activity thermogenesis (sometimes referred to as non-exercise associated thermogenesis), is the amount of calories you expend on a daily basis from non-planned movement or exercise. Non-activity calorie expenditure could include walking during work, talking, going to the store or doing household chores. Again, NEAT does NOT include planned gym cardio, conditioning and weight training sessions.

You typically have control over the incidental expended calories that are excluded in NEAT. You can choose to not go to the store, or to not clean your house, etc.

EAT - EAT, or exercise associated thermogenesis, refers to daily expended calories that come from planned exercise sessions. So for EAT, incidental exercise, such as going to the store or walking during work, is not included. Only your cardio, resistance training, Zumba, p90x, etc. sessions are totaled.

TEF - TEF, or thermal effect of feeding, is the amount of energy burned directly related to food intake and digestion. TEF will vary based on a meal's fiber and macronutrient composition.

TEF is measured as a percentage of a meal's overall calories. A typical meal's TEF is around 15%. An all protein meal might have a TEF as high as 25%, while the TEF of fat is typically below 5%. Carbs fall somewhere in the middle, and can land anywhere between 5 to 25% TEF. Fiber also has a high TEF.

TDEE - TDEE, or total daily energy expenditure, is the combination of your BMR, NEAT, EAT and TEF. It is the complete amount of calories you burn on any given day.


Factors That Impact BMR and TDEE

Here are some of the major or important factors that impact your TDEE, or total daily energy expenditure.

  • Testosterone Levels - Long term (as opposed to abrupt) decreasing changes in testosterone levels can lower your BMR.
  • Sex - Men general have higher BMRs than women.
  • Health - If you are sick or injured you typically are not moving around as much.
  • Puberty - If you are growing at a rapid pace then you are probably expending more energy than normal.
  • Pregnancy - Pregnancy will increase your energy expenditure.
  • Weight - The heavier you are, the more energy you will expend sustaining this weight.
  • Muscle Tissue - Extra muscle tissue increases the amount of energy you expend on a daily basis.
  • Job - Sedentary job, or always on your feet and moving?
  • Exercise - Exercises impacts TDEE, obviously.
  • Diet Composition - Diet composition impacts your TEF, which can increase or decrease daily expended energy.
  • Non-Planned Exercise Activity - Are you a busy body or do you lop in front of the TV at night?
  • Body Temperature - The higher your temp, the more energy you burn.
  • Thyroid Hormone Levels - High levels increase BMR.
  • Caffeine and Tobacco - Using these can increase your BMR.
  • Climate - Working or sleeping in an environment that is a little hotter or cooler than normal will lead to greater energy expenditure.
  • Stress - If you are stressed out you will typical see an increase in your energy expenditure.

Bodyfat Reading

Estimating Your BMR

Listen below are several methods used to determine daily calorie requirements.

Katch-McArdle BMR Formula​

The Katch-McArdle method is considered a reliable method of estimating your daily BMR if you are fairly lean and have a reasonably accurate estimation of your body fat percentage. The equation is:

BMR = 370 + (21.6 x LBM)

LBM is your lean body mass in kgs (not pounds), or total weight minus your fat weight.

Cunningham Formula For BMR

Another formula that hinges on having an accurate body fat percentage reading.

BMR = 500 + (22 x LBM)

LBM is your lean body mass in kgs (not pounds), or total weight minus your fat weight.

Mifflin St Jeor BMR Equation

This equation was considered the best BMR calculator until around 1990 or so. It does not taken into consideration body composition.

Mifflin St Jeor BMR Equation

The variable "s" is +5 for men and -161 for women.

"m" equals weight in kilograms.

"h" equals height in centimeters.

"a" equals age in years.

Original Harris-Benedict BMR Equation​

The original Harris-Benedict equation was create in 1919. It contains 2 different formulas, one for men and one for women. For men:

Harris Benedict for Men

For women:

Harris Benedict for Women

"m" equals weight in kilograms.

"h" equals height in centimeters.

"a" equals age in years.

Revised Harris-Benedict BMR Equation​

In 1984 the Harris-Benedict equation was reworked to include modern data. the revised equation for men is:

Revised Harris-Benedict for Men

For women:

Revised Harris-Benedict for Women

Activity Multiplier - Calculating Your TDEE​

BuiltNow that you have estimated your BMR, you will want to multiply it by one of the following factors based on your activity level.

  • Sedentary - BMR x 1.2: Don't get much exercise at work - desk job. You them come come at "veg" in front of the TV.
  • Lightly Active - BMR x 1.375: Some daily activity, plus you exercise or perform a sport 1-3 days per week.
  • Moderately Active - BMR x 1.55: A fair amount of daily activity, plus you exercise or perform a sport 3-5 days per week.
  • Very Active - BMR x 1.725: Very active, and you exercise or play sports 6-7 days per week.
  • Highly Active - BMR x 1.9: Extremely active, including up to twice a day training and/or a very physical job.

Understand that these numbers are designed to give you a rough estimation. The first 2 weeks at a new calorie level can result in abnormal weight gain or weight loss as your body accumulates or flushes water weight due to changing sodium and carb intake levels. Do not worry about weight gained or lost during the first 2 weeks of a cut or bulk unless it is unusual.

After this 2 week period you will want to monitor your weight and make slight adjustments based on goals.

Macronutrient Intake Levels​

Now that you know how many calories you will be eating per day, it's time to determine the macronutrient makeup of your diet. Once again, macronutrients are: proteins, fats and carbs.

  • Protein - Contains 4 calories per gram
  • Fats - Contain 9 calories per gram
  • Carbs - Contains 4 calories per gram

Fat Intake​

Fat does not make you fat. Your body needs a reasonable amount of fat intake for general health. Fat intake should comprise 20-35% of your overall daily calorie needs.

If you feel you function better on high carbs, then a 20-25% daily fat intake might be an option. If you have problems eating enough food, or you are carb-sensitive, then a higher fat content is recommended.

Protein Intake

Protein intake can be a controversial topic. Some folks claim you should never eat over 150 grams per day. While the effectiveness of eating over 150 grams per day for muscle building is debatable, there are certainly dietary reasons for eating more than 150 grams.

Extra protein intake is perfectly safe unless you have a pre-existing kidney function issue. If you are underweight, or on a bulk and building muscle at a rapid pace, then I recommend 200 to 250 grams of protein per day depending on your calorie requirements.

If you are eating a ton of calories per day, push your protein intake to around 250 grams. If your calorie intake is around 3000, then 200-220 daily grams might be a good option. I will also add that if you have already built a quality amount of muscle mass, or you are on a cutting diet, then it might be worth your time to eat a little more protein than normal.

For lifters who are gaining at a moderate pace and on somewhat of a slow and clean bulk, then 180 to 220 grams of daily protein is a good choice. Again, align your intake based on you calories needs and or dietary preferences.

Women should consider eating 100-120 grams of protein per day. If you are a younger woman and/or highly active, eat 120 grams per day.

Carb Intake

Now that you know your daily protein and fat intake levels, you can easily determine your carb requirements.

Keep in mind that you can adjust these numbers and levels as needed, based on what your body is telling you. I functioned better on higher carbs when I was younger, and better on higher fats in my 40s.

Listening to your body is very important. Remember to make small, gradual changes so you can assess future needs more easily.