A balanced diet is one that provides all the nutrients one needs, in the right proportion, in order to:

•   Prevent deficiencies
•   Maintain optimal physiological functions
•   Promote health
•   Prevent diseases
•   Prevent toxicity

The primary requirement of a living being is energy, which we get from calories. Generally the first question that arises in an individual's mind is "How many calories do I need?" This is a rather difficult question to answer. The number of calories an average person requires is the number that will allow him or her to maintain an appropriate body weight.

So, the next question follows, "What is an appropriate body weight for my age?" At one time, it was believed that it was acceptable to put on some amount of weight, as one grows older. However, research now clearly indicates that even a modest weight gain of 20 pounds in adulthood is associated with an increased risk of developing life threatening diseases.

A rule of thumb that is often used to calculate appropriate weight is as follows:

For Women: 100 pounds for a height of 5 feet, plus 5 pounds for every additional inch +10%. Therefore, a female who has a height of 5 feet 2 inches should weigh about 110-115 pounds +10%. The normal weight range would be 94-126 pounds depending upon the individual's body build.

For Men: 106 pounds for 5 feet plus 6 pounds for every additional inch +10%. Therefore, a male who has a height of 5 feet 8 inches should weigh about 154 pounds +10%. The normal weight range would be 139-169 pounds depending upon the individual's body build.

Once you have calculated your appropriate body weight, to calculate your calorie requirement, multiply your body weight by 13 if you have a sedentary life style. If you exercise for at least 30 minutes, five times per week, multiply your appropriate body weight by 15-17%, depending on the intensity of the exercise you do.

A female whose body weight is 100 pounds and walks briskly for 30 minutes, 5 times per week would have a calorie requirement of 115 x 15, equaling 1725 calories.

The drawback of depending upon this approach of calculating calorie requirements is that every individual differs in the rate at which they utilize energy. Two people who are of the same size and do the same amount of work may still have rather different caloric needs due to their innate metabolism.

If you are able to calculate how many calories you need, it is often difficult to calculate how many calories you are consuming since we have very little data on the caloric content of Pakistani food. So, if you are able to maintain an appropriate body weight, irrespective of the amount of food you consume, then you are doing fine.