Personal Calorie Lab

Personal Calorie Lab

How to Calculate Your Daily Calorie Needs
Harris-Benedict Formula

A more accurate way to calculate your daily calorie needs is to determine basal metabolic rate (BMR) using multiple factors, including height, weight, age and gender, then multiply the BMR by an activity factor to determine your total daily energy expenditure (calories). One calculation method is the Harris Benedict formula.

The Harris-Benedict Formula

The Harris Benedict equation is a calorie formula using the variables of height, weight, age, and gender to calculate basal metabolic rate (BMR). This is more accurate than calculating calorie needs based on total body weight alone. The only factor it omits is lean body mass and thus the ratio of muscle-to-fat a body has. Remember, leaner bodies need more calories than less leaner ones. Therefore, this equation will be very accurate in all but the very muscular (Harris-Benedict will under-estimate calorie needs) and the very fat (Harris-Benedict will over-estimate calorie needs).

Two Steps to Determine Daily Calorie Needs

• First, determine your BMR.
• Second, apply the Activity Multiplier.

Harris Benedict Formula for Women - STEP 1

BMR = 655 + (9.6 X weight in kilos) (divide weight in lbs. by 2.2 to convert to kg) + (1.8 X height in cm) - (4.7 X age in years).

Notes:
1 inch = 2.54 cm.
1 kilogram = 2.2 lbs.

Example of BMR
You are 32 years old
You are 5 feet 4 inches tall (162.5 cm)
Your weight is 185 pounds (84 kilos)
Your BMR is 655 + (806) + (291) - (150) = 1602 calories

Harris Benedict Formula for Women - STEP 2

To determine your total daily calorie needs, now multiply your BMR by the appropriate activity factor, as follows:

• If you are Sedentary - little or no exercise
  Calorie-Calculation = BMR X 1.2
• If you are Lightly Active (light exercise/sports 1-3 days/week)
  Calorie-Calculation = BMR X 1.375
• If you are Moderately Active (moderate exercise/sports 3-5 days/week)
  Calorie-Calculation = BMR X 1.55
• If you are Very Active = BMR X 1.725 (hard exercise/sports 6-7 days/week)
  Calorie-Calculation = BMR X 1.725
• If you are Extra Active (very hard daily exercise/sports & physical job or 2X day training)
  Calorie-Calculation = BMR X 1.9

Total Calorie Needs Example

If you are sedentary, multiply your BMR (1602) by 1.2 = 1922
Your total daily calorie requirement is therefore 1922 calories.
This is the total number of calories you need in order to MAINTAIN your current weight.

Harris Benedict Formula for Men

BMR = 66 + (13.7 X weight in kilos) + (5 X height in cm) - (6.8 X age in years)

Notes:
1 inch = 2.54 cm.
1 kilogram = 2.2 lbs.

Example of BMR
You are 25 years old
You are 6 feet tall
Your weight is 220 pounds
Your BMR is 66 + (1370) + (914) - (170) = 2180 calories

Harris Benedict Formula for Men - STEP 2

To determine your total daily calorie needs, now multiply your BMR by the appropriate activity factor, as follows:

• If you are Sedentary - little or no exercise
  Calorie-Calculation = BMR X 1.2
• If you are Lightly Active (light exercise/sports 1-3 days/week)
  Calorie-Calculation = BMR X 1.375
• If you are Moderately Active (moderate exercise/sports 3-5 days/week)
  Calorie-Calculation = BMR X 1.55
• If you are Very Active = BMR X 1.725 (hard exercise/sports 6-7 days/week)
  Calorie-Calculation = BMR X 1.725
• If you are Extra Active (very hard daily exercise/sports & physical job or 2X day training)
  Calorie-Calculation = BMR X 1.9

Total Calorie Needs Example

If you are lightly active, multiply your BMR (2180) by 1.375 = 2997
Your total daily calorie requirement is therefore 2997 calories.
This is the total number of calories you need in order to MAINTAIN your current weight.

How Many Calories Do You Need to Lose Weight or Gain Weight

Now you know what your calorie-needs are, find out how many calories you need each day in order to lose or gain weight.

Data Table: Only do the data table for your gender.

For Women

For Men

Questions:

1. Why do you think there are two tables for men and women?

1. Why is the age factor for women only 4.7 while for men it is 6.8?

1. Why is the weight factor different for men and women?

1. The height factor for women is only 1.8; whereas, for men it’s a 5. Why is this?

1. The biggest difference is the BMR number for men and women. The women’s number is ten times greater than that of the men. Why do you think this is true?

1. Can you think of two or three factors that are not accounted for in this calculation?

1. The total number (after you have added all the numbers together) is equal to the amount of calories you need to ______your body weight. If you want to lose weight, your total amount of calories must be ______than this number. If you desire to gain weight, you must eat ______than this number of calories.
2. A calorie measures an amount of ______.

1. What is the difference between a Calorie and a calorie?

1. Now take the fast food sheets and remembering your last meal (breakfast, lunch, or dinner) at a fast food restaurant (choose either McDonalds, Burger King, Wendy’s, Taco Bell, KFC, or Subway) add up the total number of calories in that last meal you ate there. If it has been so long that you cannot remember your last meal, choose items off the menu that you usually purchase when eating at your favorite fast food restaurant.

Data Table 2: My last meal at ______(name of fast food restaurant)

1. Take your total number of calories from this fast food meal and divide it by the total number of calories you need in order to maintain your weight and multiply by 100 to find out how much of your caloric intake was used up by just one fast food meal.

Calories of fast food meal ____ / calories per day for current wgt. ____ x 100 = ______

Now let’s look at FAT! Recommended Daily Fat Intake

1. Percent daily values on nutrition facts labels are based on a 2,000 calorie diet. Values for 2,000 and 2,500 calories are rounded to the nearest 5 grams to be consistent with the nutrition facts label.

Source: Dietary Guidelines for Americans, 2005. Web: .

1. Calories are only part of a healthy diet. We must also look at other parts of nutrition as well. Now look at your fast food meal and find the number of grams of fat.
2. For McDonalds, Subway, KFC, Wendy’s and Taco Bell see the nutritional guides on reserve with your teacher.
3. BK in an easier to read format can be found at

1. Using the chart above, how many grams of fat are you supposed to have as a maximum per day? (Note you may have to round your calories to get a usable number from the table above. Use common rules of rounding—5 and higher round up; 4 and under round down.)

1. Now figure your percentage of fat consumed in that fast food meal compared to the total grams of fat you are supposed to have per day.

Formula: Number of grams for meal ______/ number of fat grams per day x 100 = ___% fat used in one fast food meal

1. Now compare your calorie and fat percentages that you just figured and compare that to the percentages for other nutrients as given on the tables.

* values on table which are based on 2,000 calorie diet which may be more or less than your daily caloric intake

1. Which percent is highest of these nutritional components?

1. What conclusion have you come to concerning your nutritional choices at fast food restaurants?

1. If you had to eat at fast food, what menu items could you choose so that you got approximately one-third (assuming this is one out of three meals you are eating daily) of your calories, fat, Vitamins A and C, Ca, and Fe?

Design the meal here (Don’t forget the beverage):

At what fast food restaurant are you eating? ______