We’ve all heard the saying: “Workout More. Eat Less.” While that can be an effective way to see results for improved health and weight loss, a lot of people have no idea what eating less means; very frequently a person has no idea how many calories they need to eat on a daily basis.
Did you know that at the core of your body’s functions, you need calories to keep it running? Yes, you actually need calories to keep your heart beating, your digestive system functioning and your brain to keep on thinking and monitoring what you are actually doing! This is called your Basal Metabolic Rate or BMR.
When you do not get enough calories or you eat below your BMR, you will start to see some issues occur, like an inability to concentrate, issues with your digestive system or constantly feeling fatigued. In the long run, you will develop a lot more serious problems all the way up to losing function of some basic life-supporting systems. Not eating enough can actually kill you over time!
So how do you figure out how many calories your body needs to keep functioning on a daily basis? Here’s an equation to use to figure out your BMR:
For Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) – (6.8 x age in years)
For Women: BMR = 665 + (4.35 x weight in pounds) + (4.7 x height in inches) – (4.7 x age in years)
Every activity you do while awake adds to your need for overall calories on a daily basis. Even sitting at a desk and typing burns calories, though not a lot of calories! (More than when you are asleep though!) Simple Activities of Daily Living or ADL’s add to the calories you need for the day. Here is a simple way to compute that total caloric amount to maintain your weight:
| Activity Level | Examples of Activity/Exercise | Equation |
| Sedentary | Sitting, Watching TV, Reading, Driving, Cooking, Ironing, Typing, Playing Cards | BMR x 1.2 |
| Lightly Active 2-3 days/week | Cleaning, Golf, Yoga, Gardening, Walking 2.5-3.0 mph, leisurely biking | BMR x 1.375 |
| Moderately Active 3-5 days/week | Cycling, Tennis, Dancing, Weight Lifting, Baseball, Raking, Walking 3.5-4 mph, hiking | BMR x 1.55 |
| Very Active 6-7 days/week | Basketball, Soccer, Climbing, Hiking with a load, High Intensity Interval Training (HIIT) | BMR x 1.725 |
| Extra Active | Physically demanding job, Working out 2x/day or more at higher intensities | BMR x 1.9 |
Example: BMR X moderately active
1303 x 1.55 = 2,019 calories/day to maintain weight
For a simpler way to calculate both BMR and your overall recommended daily caloric intake, please visit ExRx.net’s Estimated Calorie Requirements Calculator.
On this website, you will enter your weight, height and age, as well as what you do for every hour of the 24 hour day. The best way to do this is to start with how long you are asleep, then walk yourself through a typical day, listing what you do for every single hour you are awake. Use the descriptions on the page to divide up your day. Once you hit calculate, your BMR, Activity and Total Calories will be computed for you.
The American College of Sports Medicine recommends that the minimum amount of calories a day that a person should eat is 1200 calories for a woman and 1800 calories for a man. Any less than this amount is very hazardous to your health. Dropping about 500 calories, less than your recommended intake to maintain your weight will result in about a healthy 1-pound loss per week. If you are sedentary, it will be significantly more difficult to lose weight since you must still eat enough calories to keep your body functioning. Adding in activity on a daily basis can help ensure that you are able to decrease your caloric intake within a safe level.
By Pamela G. Huenink, MS, EP-C, W.I.T.S. Faculty