By the strictest of definitions a calorie deficit means ‘any amount of calories that falls short of the amount of calories needed to fuel the energy needs of your body’. Or, put another way: A calorie deficit is any amount of calories that is unable to maintain a persons body mass.
A calorie deficit is ANY amount of food that results in loss of body mass.
By this definition you cannot be in a deficit if you are not losing body mass. You can be eating less, a little, not much, and not lose body mass since these are all subjective descriptions of an amount of food, but if you are eating less food than is required to provide the energy you need to power your daily activities then a loss of mass must occur. The loss may be small, barely noticeable except by the most advanced of scientific equipment, but it needs to be there.. and if it is there, then you were eating less calories than you needed.
It does not matter if you were eating 700 calories or 7,000 Calories of some special super-scientific diet… If a loss of body mass occurred you were in a deficit, if it didn’t then you were not in a deficit.
This is where experts and gurus prey on people – by playing with the meanings of words. A deficit is NOT a number less than what a calculator told you to eat. And a deficit is certainly NOT any amount of calories less than what you are used to eating. The amount of calories it takes to be in a deficit is also NOT fixed – it changes from day-to-day and month-to-month, depending on a number of factors including your activity level, body composition, age, and a whole host of other factors. It is a moving goal post that is and always will be defined by a loss of body mass.
If you eat a prescribed number of calories from some diet given to you by some weight loss coach and you do not lose body mass, you are NOT BROKEN, the diet was.
Now here’s a trick, you may have noticed I keep saying ‘body mass’ instead of ‘weight’. This is because for a true deficit it must actually be part of your body that is used as fuel to make up the deficit – so an actual loss in body mass. This loss may be masked by fluctuations in body weight caused by water or the weight of the food in your digestive track – Things that can make your body WEIGHT go up or down by as much as 20 pounds in the most severe of cases… so don’t let people try and trick you by using the semantics of the term ‘weight’, and make no mistake, it is the loss of body mass that defines the deficit, not eating under and estimated amount of needed calories.
The Loss of Mass defines a Deficit
Put this way, you can see why people get so confused about calories and weight loss. It is absurd to say that you can lose body mass without being in a deficit. They are inseparable. It’s like saying you can be in a deficit without being in a deficit, or you can lose body mass without losing body mass.
Loss of mass is the ONLY evidence of a deficit. If you ate 1,400 calories and lost body mass you were in a deficit. If you ate 7,000 Calories of all fat and protein and somehow lost body mass then you were also in a deficit.
This does not mean that fluctuations cannot occur WITHIN that body mass. If you gain 5 pounds of muscle and lose 10 pounds of fat, you have still lost body mass. But doing the reverse, gaining 10 pounds of muscle and losing 5 pounds of fat would require a surplus of calories, since total body mass has gone up.
In the end the amount of calories you eat is irrelevant, as is the type of body mass you lost (THESE are the issues that people can argue make one diet or exercise program better than another), but they do not change the meaning of a calorie deficit – you must be losing body mass in order to say you are eating at a calorie deficit, and you must be in a deficit to say you are losing body mass.
So ALL diets reduce body mass in the same manner – by creating a rolling calorie deficit. It’s how Eat Stop Eat works, and it’s how every other diet works too. How sustainable that deficit is, and it’s affects on the different components of body mass (fat, muscle etc) can change from one diet to another but the main principle behind what is driving your loss of mass (hopefully fat mass) is the same.
BP
