Calculating your Energy Needs to Meet Your Goals

I can almost guarantee that if you’re reading this you’ve either a) used MyFitnessPal or a similar app or b) have heard of it. I want to start out by saying that this post is not about bashing MyFitnessPal. In all honesty, I’m a huge advocate for using some form of food and exercise log to be mindful of what you put into your body and how much you move.

For myself, my food log shows that I LOVE to snack and tend to eat smaller meals throughout the day to accommodate my habit (this girl loves her popcorn and dark chocolate). For somebody else, a food log might reveal late night eating habits or their regular skipped breakfast that is causing them to overeat later in the day and thwarting their efforts to lose weight or reach their goals. For this reason, food logs of any kind (written, electronic, etc.) are great for identifying individual eating patterns.

The challenge with MyFitnessPal is that calorie estimates are set for you upon creating an account that offer limited guidance to help you evaluate whether that estimate is appropriate for you and your goals. Remember this screen?

Want to know how MyFitnessPal spits out their calorie estimates? Essentially, they take your gender, height, current weight, weekly weight loss/gain/maintenance goal and activity level and put it into an algorithm. The concern I have with MyFitnessPal is when a 5’10” young woman is encouraged to eat 1200 calories a day. For almost every adult, male or female, there is no need to eat fewer than 1200 calories a day. Period.

Enter the dietitian’s secret weapon – energy requirement equations. These equations (yes, we are doing math today) are going to consider similar information as MyFitnessPal including your gender, age, etc. but have been proven through research to be an accurate estimate of energy needs in healthy adults. If you want to learn how to calculate your energy needs keep reading!

The equation by itself calculates what we call your resting metabolic rate or RMR. This is just a fancy way of saying the energy your body needs at rest to do things like breathe, break down food and keep your body at 98.6 degrees. And in case I forgot to clarify, energy = calories.

The second step of calculating your energy needs involves multiplying your RMR by an activity factor to get what we call your total energy expenditure (TEE). An activity factor accounts for how active you are day to day.


Lets walk through, step-by-step, how you can calculate your energy needs to better meet your goals!

STEP 1 – Calculate your RMR

Men = 4.55 * (weight in pounds) + 15.875 * (height in inches) – 5 * (age) + 5

Women = 4.55 * (weight in pounds) + 15.875 * (height in inches) – 5 * (age) -161

STEP 2 – Pick your activity factor (AF)

  • Sedentary (little to no activity) = 1-1.39
  • Low Active (exercise 2-3x/week) = 1.4 – 1.59
  • Active (exercise 4-5x/week) = 1.6-1.89
  • Very Active (athletes, intense exercise 6-7x/week) = 1.9-2.5

STEP 3 – Calculate your calorie needs

  • Take your RMR from Step 1 and multiply it by your activity factor (AF) from Step 2

Here’s an example you can follow along with- Female, 5′ 7″ (67 inches),  150 lb, 25 years old;  walks 2x/week

Step 1 = 4.55 (150) + 15.875 (67) – 5 (25) – 161 = ~1460 calories

Step 2 = Activity factor = 1.4 – 1.59

Step 3 = Calculate the lower range = 1460 * 1.4 = 2044 calories

Step 3 = Calculate the upper range = 1460 * 1.59 = 2321 calories

STEP 4 (optional) – Calculate energy needs for weight loss and weight gain

  • Weight loss = Subtract ~500 calories from number in Step 3
  • Ex. 2044 – 500 = 1544 calories for a 1 lb/week weight loss
  • Weight gain = Add ~500 calories to number in Step 3
    Ex. 2044 + 500 = 2544 calories for a 1 lb/week weight gai
    n

Conclusion – To maintain her weight, this women would need to eat between 2044 and 2321 calories each day. To lose weight she would need to eat between 1544 and 1821 calories each day.


IMPORTANT – These values are estimates and that’s why they fall within a range. Keep in mind that these numbers should be used as a guide and are not the end all be all. If you are struggling to lose/gain weight, it might be worthwhile to calculate your energy needs to see how your current intake compares to the equation.

On the flip side, if you’re already using something like MyFitnessPal and you find yourself developing obsessive or restrictive behaviors because of logging your meals, it may be worthwhile to speak with a medical provider or dietitian about this as it may indicate that this tool is more harmful than helpful for you. Need a referral to a dietitian in your area? Shoot me an email here.

These equations also are intended for healthy individuals. Meaning, that if you have an underlying health condition like Crohn’s, Cystic Fibrosis, etc. these may not be appropriate and you should speak with a dietitian in person to figure out what the best option is for you. If you want to talk about meal planning, your exercise regimen, or specific goal setting, it might be worthwhile to sit down with a dietitian in your area. Need help finding one? Shoot me an email here and I’d be happy to refer you.

Disclaimer – This post contains general information related to determining your energy needs. It should not be used in place of a advice or expertise from a medical provider. If you have questions, talk with your provider.