How to set the right calories for weight loss? We know more or less that, if we want to lose about half a kilo a week, we have to cut 500 calories to lose weight: either from the diet, therefore making a low-calorie diet of less than five hundred calories from our normal (i.e. norm-calorie) diet, or from activity, therefore burning 500 calories a day, or both, or setting a lower calorie deficit from the diet and doing physical activity (for example, if to stay in my weight I have to introduce 1800 calories a day I do 1600 calories of diet and I train every day to cut another 300 on average).
But these are calculations, and the risk of using only calculations is that if we make a mistake we are faced with two scenarios: 
–we do not lose weight , because we have overestimated the calories consumed or were not precise in cutting the right calories from the diet. We use apps badly, we don’t dose the ingredients well, we think we burn 100 calories and we burn 10, etc.
– we do not lose weight because we have cut too many calories, and after an initial weight loss, we no longer lose weight. In this case, we keep a diet that is too rigid for us, with the result that the metabolism is lowered and we no longer lose weight despite the good will.
The problem in both scenarios is underlying. I can know how many calories I have to cut to lose weight, but I have to start with the whole cake to be able to cut a slice, that is, I need to know exactly what my daily calorie requirement is. To find out, you need to do two things. 
The first : use the Mifflin-St formula. Jeor, which according to this study is the most accurate, using this online calculator (in English) and selecting Metrics as the unit of measurement. In my case it tells me that to maintain my weight I have to eat 1876 calories. Right? No, because I eat two thousand and I tend to lose weight or at least stay within my weight. The reason? If I also selectmy activity level and I say I train three to four times a week, the formula can’t tell what kind of physical activity I do. This is why, once we have obtained a data, we must necessarily do a second thing.

The second thing: the subjective data. To know if the estimated calories are right, we must follow a diet that is those calories to the letter. For example, in order to know that I lose weight by eating 1876 calories a day, I have to do this diet of 1876 calories a day for two or three weeks. I lost weight? Then I have to adjust the figure by increasing the calories. Did I gain weight? Then maybe I need fewer calories. Only this thing can take us even for a month and obviously EVERYTHING depends on my metabolic state. If I’ve been on a perennial diet up until that point and then eat the calories my body needs, I’m likely to get fat. This is the risk of those who are always on a diet.

What to do: The best thing is to rely on a nutritionist or dietician to do the homework for us , but for this to work, we must tell the doctor the truth . If we have done our own thing and have consumed a thousand calories a day and are stalled, we cannot fail to say. Our dietary history matters to understand how healthy we are. If we have a slowed metabolism from too many diets, the nutritionist must know, otherwise it’s like stopping at point one. It is based on an estimate, but in practice the patient’s state of health matters.
At that point the professional has the tools to evaluate our metabolic state with some more in-depth examination: for example a DEXA, blood tests, body temperature assessment, etc.
Which are things he should propose to us anyway, but it is better to be clear about our state of health.
If, on the other hand, we tell him that we are overweight and want to lose weight without mentioning how we behaved before, it is as if we told him that we have eaten too much up to that point. Maybe it isn’t.
But before we say that the dietician’s or nutritionist’s diet doesn’t work, let’s start with us: were we honest?
Or hasn’t our desire to lose weight at all costs made us mention all of our previous failures?
Only by combining the data with our specific case can we understand how to set the right calories to lose weight.