I’ve been asked a few times about calorie restrictions. Does it work? Does it not?
My answer to both of those questions is ‘Yes – but it depends’
Let’s look at it from the point of an overweight person who eats a very calorie dense ‘diet’ with calories coming from highly processed junk foods. By the sheer act of removing the junk food and having them eat a very nutrient dense (not calorie dense) ‘diet’, from as many single ingredient, whole foods as possible, this person would naturally be eating less calories then they had previously.
They would start to lose some fat, and some stored water weight.
In this instance, calorie restriction would work, in the way I mentioned above, for the brief period of time it would take for the body to naturally adapt to the change in calorie intake; at which point any loss of weight/measurements would start to slow down.
To then improve fat loss, an increase of calories may be required to improve thyroid function (metabolism) as restricting calories for an extended period can have a negative impact on this, and actually slow your metabolism down.
This takes me on to my next point:
A person who has been on a calorie restrictive ‘diet’ for months/years. I’m going to throw a bit of maths at you here, I’ll be as basic as I can.
Before restricting calories, let’s say this person had a Base Metabolic Rate of 2000kcal per day (which basically means that this person’s body requires 2000kcal per day just for basic functions like breathing, digestion, brain function, movement etc).
Now let’s say they find a generic fitness app, input a few arbitrary details (height, weight, how active they are daily) and out pops this new number of let’s say 1500Kcal needed, per day, to lose ‘weight’.
So down go this person’s calories.
They now consume 1500kcal per day
Yet they need 2000kcal per day just to function properly
But they are consuming 1500kcal per day
Yet they need 2000kcal per day just to function properly (I felt I needed to repeat that for clarity)
So what happens, after they have lost a little water weight and a little fat?
Their body MUST slow down, because it’s not able to function properly on just 1500kcal. So metabolism is slowed in response.
And fat loss slows, and stops.
Your metabolism now requires 1500kcal to function (and not very well).
And so calories get lowered, body slows, and so on and so on until you’re miserable, and angry that you’re not losing any more weight, never mind fat.
In this instance, calorie restriction would not be recommended.
In conclusion, if you’re going to reduce calories down to lose weight, do it through exercise and not food restriction.