How Many Calories Should I Eat To Lose Weight?

By: Lisa Gelbman

Break Studios Contributing Writer

How to determine the number of calories you should eat to lose weight is a common question asked by many young women, especially with the number of beautiful women in Hollywood with seemingly perfect bodies. Not to fret, a Ph.D. in nutrition and health is not required to find the perfect number of calories that works best for you. All the information you need to find your magic number is available with an honest look at yourself. Also, you should know that this magic number is not a daily number, but a weekly number. Vary the number of calories you eat per day so that you don't get stuck in a rut. Here is all of the information you will need to calculate the number of calories you should eat to lose weight:    

  • Your height
  • Your weight (no cheating!)
  • Your age (the number of calories your body burns each day change as you get older)
  • Your gender (female metabolisms have different metabolic rates than male metabolisms)

Now for the fun part, calculating your number! There are many formulas that claim to produce the perfect number, but in 2005 the Mifflin-St Jeor Formula was shown by the American Dietetic Association to be the most accurate and will be the one used here. The breakdown is as follows:

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

For those of you whose scales calculate your weight in lbs., simply divide this number by 2.2 to get your weight in kg. Also, to convert your height in inches, just multiply your height in inches by 2.54. However, keep in mind that we said that eating the same number of calories every day is not the most effective method. So, multiply this number by seven to get the number of calories you need to eat to lose weight. Then, we will figure out a way to divide this number unevenly throughout the week.

1396 x 7 = 9,772 calories per week. Now, to make your life easier and to make the process of counting calories less daunting, round this number to the nearest tenth. This makes the number of calories you need to eat to lose weight 9,770 calories per week.

For the next step, let's divide this number into seven days of varied caloric intake. Remember how we saw that your body will adjust to the number of calories you consume if it doesn't fluctuate, so this process will effectively "trick" your body, and keep that metabolism of yours running strong. For the sake of convenience, let's start with Monday:

  • Monday: 1400
  • Tuesday: 1270
  • Wednesday: 1600
  • Thursday: 1400
  • Friday: 1250
  • Saturday: 1500
  • Sunday: 1350

The easy thing about this last step is that there's no exact formula. Just make sure that there is a good degree of variation between each day so that your body can't predict how many calories it will getting. Also, whatever schedule you do layout is just a blueprint, and can be changed according to a changing schedule. For instance, if you go out with friends on Friday and eat more than you anticipated, just compensate with what you eat on Saturday and Sunday so that you still stay within your weekly limit.

 One last piece of parting advice: do not weigh yourself everyday! Body weight fluctuates due to water weight and other factors, and a daily weight check isn't helpful to determine how much weight you're actually loosing. Only weigh yourself once weekly. This will be a better indicate of actual pounds you are loosing. Good luck and happy eating!  

Resources:

Baylor College of Medicine

American Journal of Clinical Nutrition

Posted on: Feb. 28, 2010