The number of calories you should consume each day depends on your age, size, height, sex and lifestyle. A 6ft 2in male, 22 years of age requires more calories than a 5ft 2in woman in her 70s.

What are calories?

Calories are a measure of how much energy food or drink contains. The amount of energy you need will depend on:

• Your age: for example, growing children and teenagers may need more energy
• Your lifestyle: for example, how active you are
• Your size: your height and weight can affect how quickly you use energy.

Maintaining healthy weight

To maintain a healthy weight, you need to balance the amount of calories you consume through food and drink with the amount of calories you burn through physical activity. The healthy way to lose weight is by using more energy than you consume, eating a healthy diet with less calories and` increasing daily activity.

Gaining Weight

If you’re underweight (your BMI is less than 18.5), you should get advice from your General Practitioner. To gain weight, you need to eat more calories than your body uses each day.

Calories needed to lose weight

Calculating the number of calories you need to lose weight is a relatively simple, three-step process. The Harris-Benedict equation is the most widely used method of calculating your calorie needs (and thus your calorie needs for weight loss). Here is the Harris-Benedict equation for men & women:

Men : BMR = 66.4730 + (13.7516 x weight in kg) + (5.0033 x height in cm) – (6.7550 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)

You just need to plug in your age, height, and weight. The resulting number is the recommended daily kilocalorie intake to maintain current body weight.