The breakdown of the diet is a fundamental step in the drafting of any dietary therapy.
After calculating the basal caloric requirement (basal metabolism or MB) and the specific caloric requirement (hypo, normal or hyper caloric), it is necessary to divide it in two different ways:
- Breakdown into nutrients
- Energy breakdown of meals
The breakdown into nutrients is an indispensable procedure for the accuracy of the diet; its purpose is to establish the right nutritional balance of the macro-molecules: proteins, lipids and carbohydrates. Obviously, these three nutritional principles have very different characteristics, therefore, the calculation of the nutritional distribution must take into account:
- Recommendations for a correct and balanced diet
- The specific and subjective nutritional needs in relation to physical activity
- Possible presence of metabolic pathologies
A CORRECT diet boasts the following energy percentages:
- Protein: on average 12-13% of calories or better 0,75-1,5g per kilogram of desirable physiological body weight (which includes NORMAL body mass percentages). Proteins must be calculated with reference to age and the level of sporting activity, moreover, it would be advisable for at least 1/3 of the protein intake to be of animal origin to ensure a good overall biological value.
- Lipids: they range from 25 to 30% of calories; They MUST comprise 2,5% essential fats and should consist of 2/3 unsaturated lipids and 1/3 saturated lipids.
- Carbohydrates: represent the remaining calories (MAX 63%), that is: kcal of CHO = kcal TOT - kcal of Proteins - kcal of Lipids; NB only 10-12% of the total energy should derive from simple carbohydrates (glucose-fructose-galactose-sucrose-lactose-maltose)
With such a "starting point", the nutrition professional is able to SHAPE the nutritional distribution on the basis of specific and subjective needs; in the event that the level of physical activity is VERY high and is characterized by the practice of intense and frequent sport, it is possible (and desirable!) to manage the percentages and grams of macronutrients in the most congenial way. For example, a cross-country athlete who shows serious difficulties in maintaining muscle trophy due to the high volume of aerobic activity (for example from 6 to 10 hours per week), could use a DOUBLE protein coefficient compared to a sedentary subject, or : 1,5gxkg instead of 0,75gxkg of desirable physiological body weight.
The other fundamental aspect that should be taken into consideration is the possible presence of metabolic PATHOLOGIES or concerning the efficiency of the kidneys, liver, pancreas, stomach, intestine, etc. This means that, for example, when treating a diabetic subject it could be useful to keep the percentage of carbohydrates to a minimum (50-55%), in particular the simple ones (10%); the same could be applied to saturated or hydrogenated fats in reference to a hypercholesterolemic subject, or to proteins in some cases of renal insufficiency.
By energy breakdown of meals, on the other hand, we mean the overall caloric breakdown in the different meals of the day. We remind you that, although in practice the subjective needs are mainly taken into account (work habits and sporting activities), there is a general scheme that can be easily applied in most cases. It provides for an energy distribution of:
- 15% of calories at breakfast (not less than 12-13% and not more than 20%)
- 05% of the calories in the mid-morning snack (not less than 4% and not more than 8-10%)
- 40% of the calories in lunch (not less than 35% but absolutely not more than 40%)
- 05% of the calories in the mid-morning snack (not less than 4% and not more than 8-10%)
- 35% of the calories in dinner (not less than 30% but absolutely not more than 35-40%)
It should be noted that the nutritional organization of the sportsman, and above all of the elite athlete, leaves out most of these percentages; this happens because in the presence of very high energy needs (from 4000 to 6000kcal per day), the sportsman often manifests considerable digestive and organizational difficulties which it would be appropriate (and convenient!) to comply ALSO through the use of food supplements; the consumption of single meals which often reach 2000kcal is not easy to manage.
