A calorie is a measure of energy, it is used to measure the energy you take in through food and the energy you expend through daily activities.
You body uses energy for keeping you alive, basic bodily functions such as pumping blood round your body, breathing, digesting food all require energy and that’s before you start standing up, walking around, working or even doing any exercise.
The basic principal of weight loss is that you must burn more calories than you consume, this is called creating a calorie deficit. The size of the calorie deficit is determined by Calories In minus Calories Out, to burn 1 lb of fat you need to create a calorie deficit of 3,500 calories.
A woman consumes 1,500 calories a day and expends 2,000 calories a day for 1 week
= (1,500 calories in – 2,000 calories out) X 7 days
= -500 calories per day
= -3,500 calories per week
= 1 lb of weight loss in a week
An average man requires 2,500 calories a day to maintain his weight while an average woman requires 2,000 calories a day. The amount of calories required a day to stay at the same weight depends on your weight, the heavier your body the more energy required to fuel it.
Unless under medical supervision you shouldn’t reduce your daily calorie intake to less than 1,200 calories for a woman or 1,800 for a man and do not aim at losing more than 2lbs per week. So don’t just stop eating or drastically cut back your calorie intake to much, this will not work, your body will just go into starvation mode and change the rate at which it burns calories.
The typical calorie deficit you need will be between 500 and 1000 calories per day which will result in you losing 1 to 2 pounds of weight per week.