Precision Nutrition System

Precision Nutrition System
Healthy Eating For Fat Loss

Tuesday, September 20, 2005

How many calories should I eat

How many calories should I eat if I want to lose weight?


Unfortunately, there's no magic number of calories we should all eat each day. You'll need to assess your own caloric needs based on several factors.

First you'll need to figure out how many calories you can eat to stay the weight you're at right now.

To estimate how many calories you should consume in order to maintain your weight, you'll need to do a little math. By using a simple formula called the Harris-Benedict principle, you can assess your basal metabolic rate -- also known as your BMR.

(Then, to lose weight, you'll need to cut calories or burn extra calories and shoot for a level lower than the results you get with this formula.)

Your BMR is the amount of energy your body needs to function.

We use about 60 percent of the calories we consume each day for basic bodily functions such as breathing.

Other factors that influence your BMR are height, weight, age and sex.

Step one is to calculate your BMR with the following formula:

Women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years)

Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in years)

Step two: In order to incorporate activity into your daily caloric needs, do the following calculation:

If you are sedentary : BMR x 1.2

If you are lightly active: BMR x 1.375

If you are moderately active (You exercise most days a week.): BMR x 1.55

If you are very active (You exercise daily.): BMR x 1.725

If you are extra active (You do hard labor or are in athletic training.): BMR x 1.9

In order to lose weight, you must create a calorie deficit. It is easier and healthier to cut back your calorie intake a little bit at a time. Every 3,500 calories is equivalent to 1 pound.

If you cut back 500 calories a day, you will lose 1 pound per week. If you exercise to burn off 500 calories a day you will also lose 1 pound per week.

Ideally, you should do a combination of both, (e.g. cut back 250 calories; burn an extra 250 calories).

A healthy weight loss goal is to lose .5 to 2 pounds per week. Losing more than 2 pounds per week will mean the weight is less likely to stay off permanently. Never cut back to fewer than 1,200 daily calories without medical supervision.

To find out how you are spending your current calorie intake, keep a detailed food diary for at least one week. You can check the calorie content of most foods at Web sites like

With careful review, you will find ways to cut back those 250 calories a day: the milk in your cereal ... the can of soda you drink daily ... the butter on your toast.

Making little changes like these will really add up in the long run.

Becoming more active will knock the remaining 250 calories out. For example, a 180 pound person who walks at a brisk 3 miles-per-hour will burn just over 250 calories in 45 minutes.

Be sure to check with your doctor before significantly changing your diet or starting a new exercise regime.

No comments: