Caloric Intake to Lose Weight

The amount of energy your body needs to function is measured in calories. If you consume more calories than your body needs, you will gain weight. Take in fewer calories than your body's energy requirement and you will lose weight. Reaching and maintaining your ideal body weight begins by performing a few math calculations based on your current weight, height, age and activity levels. These calculations will help you determine the right number of calories you need for optimum health and well being.

Calculating your BMR

A single pound of stored body fat contains approximately 3,500 calories. To lose one pound of fat a week, you would need to take in 500 fewer calories a day.

Begin by determining how many calories a day you need to maintain your current weight. To do this, you will need to calculate your BMR (basal metabolic rate). BMR measures the minimum caloric intake requirement to keep your body alive while resting and is responsible for about 70 percent of daily calorie expenditure. Functions such as blood circulation and respiration are examples of activity burning calories measured by BMR.

Calculate your BMR manually by using the Harris-Benedict formula: Men: BMR = 66 + (6.23 x weight in pounds) + (12.7 x height in inches) - (6.8 x age in years); women: BMR = 655 + (4.35 x weight in pounds) + (4.7 x height in inches) - (4.7 x age in years). The BMR for a 48-year-old, 5 foot, 165-pound woman is: 655 + (4.35 x 165) + (4.7 x 60) -- (4.7 x 48) = 655 + (717.75) + (282) -- (225.6) = 1429.15 The formula may not give individuals who are very muscular or extremely overweight an exact measurement. You can also use an online BMR calculator.

The next step involves using your BMR to determine how many calories a day you need to maintain your current weight using the Harris Benedict Equation:
Sedentary = BMR X 1.2 (little or no exercise)
Lightly active = BMR X 1.375 (light exercise)
Moderately active = BMR X 1.55 (moderate exercise/ 3-5 days/wk)
Very active = BMR X 1.725 (hard exercise/ 6-7 days/wk)
Extremely active = BMR X 1.9 (hard daily exercise)

The 48-year-old woman given in the example above who is moderately active would need to consume 2143 calories a day (1429.15 x 1.55) to maintain her current weight.

Rev Up the Weight Loss

Losing weight is as simple as burning more calories than you consume. You can achieve this goal in two ways: 1) consume fewer calories per day, and 2) increase daily activity. Most experts recommend using both methods for safe weight loss.

To lose one pound of fat a week by exercise you will need to burn 500 calories a day. This is not hard to do. Based on a 165-pound woman, cleaning house for 30 minutes a day burns 108 calories; taking a 30-minute walk at 2 miles per hour burns 103 calories; driving for 30 minutes burns 79 calories; and a 30-minute low impact aerobic workout burns 227 calories.