The calorie restricted diet is the traditional diet that most people adopt when they want to lose weight. In essence, they believe that if you restrict the intake of food, and thereby indirectly restrict calories, then the inevitable will happen namely you will lose weight. Regrettably this belief is wrong - the concept that obesity is simply caused by too many calories is an absurd oversimplification. It is far more complex than this.
Therefore, simply eating less and moving more does not result in long term weight loss, and whilst the calorie restricted diet, like all other diets designed to help us lose weight, work in the short term, in the long term they fail and in fact people regain all of the weight that they have lost and a significant number will put on even more. There are two significant reasons why the calorie-restricted diet fails – the first one relates to insulin resistance and the second to BMR.
Let’s firstly look at insulin resistance. The development of obesity and an excess of insulin leading to insulin resistance go hand-in-hand. And to deal with obesity in the long term requires a return to normal insulin sensitivity. The latter can only happen if insulin levels are reduced to zero on a fairly persistent basis and this can only happen with intermittent fasting. It certainly cannot happen with a calorie-restricted diet which traditionally serves up several small meals a day.
So long as food is being taken in, albeit in small quantities, insulin levels will always be elevated and insulin resistance is always maintained. At some point the individual will start to eating the standard meal size again and the adipose tissue will be redeposited and all the weight that has been lost will be regained – and more.
Now on to BMR. As detailed in the presentation entitled daily energy requirements, the average human has fairly fixed energy needs in the form of basal metabolic rate. This accounts for approximately 95% of total daily energy expenditure and for males this is about 2500 Calories per day and for females in the region of 2000 Calories.
For a calorie restricted diet to work the amount of energy being expended, ie calories out, would need to be largely independent of energy coming into the body in the form of food ie calories in. We now know that this is far from the truth and in fact calories out is very much dependant upon calories in.
So, the first thing that happens when calories in are restricted is that there is an initial weight loss of a view kilograms. However, the body very quickly senses that calories are restricted and accordingly adjusts calories out, largely in the form of BMR, to match calories in.
And this is exactly what one would expect from a body that has homeostatic mechanisms which have evolved over millions of years. If it was unable to conserve energy in the face of restricted food intake then it would very rapidly deplete its reserves resulting in elimination of the species over a short period of time.
From a practical perspective dropping BMR equates to shutting down selectively various body functions – so the individual feels cold, tired, lethargic, irritable, hungry and generally miserable.
The next stage is that calories-out (effectively BMR) drops to match calories-in. So, if calories-in is reduced to 1500 calories per day then that is exactly what the BMR reduces to. The net result of this is that weight loss very quickly plateaus and the individual knows almost immediately that there is no further weight loss. So, we are now in a situation where the individual is no longer losing weight and at the same time feels miserable.
And the automatic response to this is to start eating again as a form of comfort. Because calories-in have now increased beyond calories-out the excess energy gets converted to stored body fat and the weight goes back on.
And the really crucial thing is that BMR does not return as quickly as anticipated so in fact the individuals weight rebounds beyond the weight they started at and as a result the individual ends up in a worse state than before. This is called the yo-yo effect and is a well-recognised phenomenon with calorie restricted diets.
Unfortunately, it does not stop individuals from widely adopting the diet, and this is largely based upon ignorance. More concerning is the fact that it also doesn’t stop so called experts such as doctors and dietitians from continuing to promote the notion that it is still the best way to lose weight. Nothing could be further from the truth.
It is important to grasp the concept that with the Nysteia Formula, and in particular with the intermittent fasting element, there is no attempt at calorie restriction. It is extremely important in adopting the Formula that a normal calorie intake is maintained. It is also essential that a normal BMR is maintained and in fact it is very helpful if calories out is increased and this is the rational of point 2 of the Nysteia Formula namely daily cardiovascular exercise for at least 30 minutes.