Sally's estimated energy requirement, based upon her age, height, and weight, is approximately 2000 kcalories per day. What is the maximum number of kcalories per day that she can consume to lose 3 pounds per month?

The maximum number of calories per day that she can consume to lose 3 pounds per month is 1650 kcal.

Explanation:

Energy (expressed in calories) is required for the normal functioning of our body and the main energy sources are macronutrients such as carbohydrates, fats, and proteins in our food. The calories consumed through food are either converted to energy or stored within the body as fat.  In order to lose weight, a person should either burn more calories by increasing physical activities or reduce calorie intake. It is estimated that in order to lose 1 pound of weight, a person should burn 3,500 calories (one pound or 0.45 kilogram of fat = 3,500 calories).

In order to lose 3 pounds per month, the total calories Sally should burn per month is 3 × 3500 = 10,500 kcal.

Therefore, the calories she should burn per day is 10,500 ÷ 30 = 350 kcal (assuming, one month = 30 days).

Sally's daily energy requirement is estimated as approximately 2000 kcalories. Therefore, the maximum calories she can consume per day to lose 3 pounds per month is 2000 - 350 = 1650 kcal.