Using the Harris Benedict Equation for Weight loss

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How Many Calories Should I Have a Day to Lose Weight?

A good way to get into the science behind your weight loss is to figure out how many calories you need to be  consuming to lose weight. Doing this will give you more accurate expectations and results! Remember that the number one rule with weight loss is you need to be burning more calories than you are taking in. In other words, weight loss requires you to be in a calorie deficit. One pound of weight adds up to about 3,500 calories. This means if you wanted to lose 1lb every week, you would want a calorie deficit of 500 calories a day. Generally a safe range of weight loss is 1-2 lbs a week. This kind of gives you an idea of why weight loss can be so difficult.

To figure out how many calories you should be consuming to lose weight, you first should probably figure out how many you should be consuming to MAINTAIN your weight. As simple as it may seem, the 2,000 calorie diet is a very robust and vague estimate of calories the “average person” should be eating.

To figure out YOUR ideal caloric intake for maintaining your weight,  use the Harris Benedict Equation. First you are going to want to calculate your BMR, or basal metabolic rate. This will require a little math, so pull out your calculator.

Men BMR = 66 + (6.23 x weight in lbs) + (12.7 x height in inches) – ( 6.76 x age)

Women BMR = 655 + (4.35 x weight in lbs) + (4.7 x height in inches) – (4.7 x age)

For Metric Units:

Men  BMR = 66 + (13.7 x weight in kg) + (5 x height in cm) – (6.76 x age)

Women : BMR = 655 + (9.6 x weight in kg) + (1.8 x height in cm) – ( 4.7 x age)

Of course if you are feeling super lazy, you can use this BMR calculator.
Then you will take your BMR and multiply it by a certain number depending on your activity level.

Sedentary (little to no exercise):  BMR x 1.2
Lightly Active (light exercise 1-3x a week): BMR x 1.375
Moderately Active (moderate exercise 3-5x a week): BMR x 1.55
Very Active(hard exercise 6-7x a week): BMR x 1.725
Extra Active(very hard exercise or twice a day):  BMR x 1.9

This Harris Benedict equation gives you a pretty accurate idea of how many calories you should be consuming daily to maintain your weight. For example, I weigh 183 lbs currently. I am 5’ 9” and am 22 years old. This gives me a BMR of 1677. Since I haven’t been going the gym lately, I would say my caregiving job keeps me lightly active, giving me a daily caloric need of 2305 calories. To lose 1-2 lbs a week, I will need to consume between 1300-1800 calories a day or increase my exercise.

Weight Loss Guidelines to Keep in Mind…reminder-8042507

  • Generally,  reducing the caloric intake by 500-1000 calories, is where most people will fall. A deficit bigger than 1,000 calories should be discussed with your doctor.
  •  If you are trying to lose 10lbs or less, a deficit of 1000 calories is generally too much. (500-800 is more reasonable)
  •  American College of Sports Medicine (ACSM) recommends that calorie levels never drop below 1200 calories a day for women or 1800 calories a day for men.

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