If you are used to reading the nutritional tables of food products, you have already realized that, as regards calories, these are divided into calories per portion and calories per hundred grams . Serving is sometimes adjusted on the basis of the RDA , which is the recommended daily allowance. Alternatively on the GDA. And this often misleads the actual caloric value of what we consume. Let’s see why.

TABLE OF CALORIES IN PACKAGED FOODS
The problem of the recommended daily ration

Now I’ll explain why you should be wary of the calorie table conceived in this way, and the indication, often placed on the front of the package, of calories.

At the basis of the recommended daily dose, at least on the caloric side, for women you will find a ceiling of 2000 calories of daily requirement, for men of 2500, according to an estimate decided by the European Union on FAO data. Alternatively, however, there is often an indistinct ceiling of 2200 calories. 

And the problem of the portion or serving

In most of the nutritional tables of products, the table of calories is often conceived “per serving”, or per serving, while it is not always written how many calories a hundred grams of that product bring. And here the problems begin, if we were to consider only the serving or the portion.

Is the product too caloric? Then the portion is reduced to a minimum. So a serving can be a cookie, a teaspoon of peanut butter, 5 fries in the fries bag.

Then on the front of the product the words “only X calories (per serving)” are put, with a portion written in small or absent.

The buyer must then read the calorie tables on the back and make the various calculations .

The more the food is dense in calories, the more ila recommended portion is reduced, so even if it is a bomb we are convinced that we can make it part of our daily diet. Who buys Nutella to eat 15 grams of it?
Since Nutella is pasty, fifteen grams is just a not too full spoon.

It would be more correct to report calories per hundred grams as the main indication, and only thereafter per serving.
And so some 50 gram chocolate bars have written “125 Kcal” in large, then in small “per serving” and only on the back we discover that according to the company 50 grams correspond to two portions (that is, half a bar).
The calculation, which in the case of a 50 gram bar is simple (I’m ingesting 250 Kcal instead of 125 if I eat the whole bar), becomes a disaster in the case of biscuits and many baked goods. Here the portion is often indicated in grams. So we have a portion of 25 grams for example with 130 calories. But we don’t know how many grams the single biscuit corresponds to. So how many calories will there be per cookie?

When the portion changes depending on the country

In an article of Il Fatto Alimentare  , it is noted how the indication of the portion changes according to the country in which it is bought.
Why these differences?
Let’s go back to the biscuit case. It becomes difficult to figure out for yourself how many calories only a biscuit has, because the serving is often expressed in grams, so thirty grams of biscuits is a portion and the portions vary from country to country.
If we wanted to do the precise, we would have to count ALL the cookies in the package and divide them by the total weight of the package. Keeping in mind that people have other things to do in life, most of us confuse “serving” with the contents of the whole package (in the case of small things, like snacks) or even believe it to be one hundred grams, underestimating the calories that ingests. And gaining weight without realizing it.

See also: portion calculation, how much to eat to lose weight.