If you have decided to go on a calorie counting diet then you need to determine how many calories your body needs to survive each day. After you determine how many calories you need you can get continue on to figure out a nutrition plan to help you lose those extra pounds. There is a number of ways people can calculate TDEE (total daily energy expenditure) ranging from using a simple body mass multiplier to more calculated ways that include having to know the amount of lean muscle mass you currently have.
On average a man needs between 2700-2900 calories a day whereas a woman would be looking to fall ideally between 2000-2100 calories. Falling between those calories ranges would for an average person allow them to maintain their current weight. Theoretically Age calculator speaking then if you were to consume fewer calories than the average you would lose weight and if you were to go over you would gain weight. There are other key factors however that must be considered. One of those factors being lean muscle mass. A person that has large amounts of muscle mass requires more energy to function then those will little muscle mass, hence raising the amount of calories they’re bodies need day to day.
The most commonly used way of calculating your BMR is to use the Harris Benedict Formula. The Harris Benedict formula uses your weight, sex, age and height to determine your TDEE. While it does not include your lean body mass which is also a factor in how many calories your body needs to live it is still pretty accurate for those who do not know the amount of lean muscle mass they have.
Men: 66 + (13.7 x weight in kg) + (5 x height in cm) – (6.8 x age in years)
Women: 655 + (9.6 x weight in kg) + (1.8 x height in cm) – (4.7 x age in years)
Using the Harris Benedict formula you have determined what your personal calories should be and so you are ready to go out and lose some weight. Approximately 3500 calories = 1 pound of fat so for some people you’re first thought may be to just starve yourself and the pounds will fall off right? Not exactly. Peoples’ bodies are designed to survive. As soon as you cut your calorie intake too low your body automatically panics and slows its metabolic rate. The slower your metabolic rate the fewer calories your body needs before it starts to store fat.
Ideally it is recommended that you decrease your calories so that they fall 500 calories or slightly more below your TDEE for healthy weight loss. If you cut your calories more than 1000 per day your body will kick into survival mode and slowing your metabolic rate. To make matters even worse once you give up on the diet and start eating normally again your body, still in starvation mode, will continue to store fat which causes the dreaded regain of everything you lost and then some.