The calorie deficit - What is it? How to use it?
It's a very simple, fundamental concept - if you eat fewer calories than you burn via exercise, your body will need to burn fat to make up the difference. The calorie deficit is the difference between the calories in your food and calories burnt, which includes the calories need to maintain your body at rest, and calories burnt through exercise. The basic energy needs of your body when resting, is your Resting Metabolic Rate (RMR). This is your basal metabolic rate (BMR) plus the extra energy needs for your basic activities throughout the day. Your BMR is the total number of calories your body requires for its routine bodily functions, generally measured when the subject is lying down (excludes any activities). This includes maintaining your body temperature, breathing, keeping your heart beating, processing food and waste, and all the other processes your body needs to maintain itself. There are many websites you can visit to work out your BMR. Similarly your Resting Metabolic Rate is worked out using a simple multiplier depending on how active you are for your normal activities - sedentary, moderately active, highly active, etc. On top of this is extra calories you consume each day through the extra exercise you undertake - a walk, jog, swim, work out at the gym, etc. The calorie deficit is the total calories burnt (RMR + exercise) minus the calories eaten in your food. It is a deficit because you are expending more calories than you are eating. The extra calories have to come from burning fat!
It is clear that you can produce a calorie deficit by eating less, exercising more or a combination of both. How much of deficit do you need to lose weight? There are about 3450 calories in a pound (500g) of stored body fat. Therefore, if you generate a 3450-calorie deficit by dieting or exercising, you will lose one pound (500g) of body weight. If you create a 14000 calorie deficit you will generally expect to shed about three pounds or 1.5kg and so on.
This is a general guide only and your actual weight loss will depend on various things including water retention, changes in your resting activity, etc. Also your RMR and calories burnt in exercise depend on weight and so both will fall as your weight falls. There are various suggestions on what sort of target you should aim for, mostly 10-25 deficit which is equivalent to 560 calories (2800/5). You could do this by eating 560 calories less in your food, or by undertaking extra exercise to burn the extra 560 calories, or so combination of both.
Given that the calorie deficit is such a fundamental key to developing and following a weight loss program, it is very surprising that very few monitoring programs estimate it directly and show it in your daily or weekly records. You should look for software or an online system that allows you to enter your calories eaten and burnt, and one that calculates and records your calorie deficit in a diary. Likewise the package should record your daily weight and your daily weight target (weekly if you prefer). Ideally the package should (like Desizeme. com) plot these values on chart so that you can see the relationship between the calorie deficit (as a percentage) and your weight loss progress. If you have all these values in a diary you can see what is working and how much you need to adjust your program to keep the weight falling off. If your weight loss plateaus, you will need to eat less and/or exercise more and a good tool will show you what works.
The final piece of advice is to adjust your calorie deficit gradually and observe your bodyweight and body fat percentage to see how you respond. If you don't see the results you expect, then you can adjust your food intake and exercise levels accordingly. The combined approach is generally better.
The Calorie Deficient - Generate it; Maintain it and you will lose weight!