You know, at Christmas it is not allowed to REFUSE a large meal! This habit, once aberrated by the community of nutrition professionals, is now considered an integral part of diet therapy and a fundamental step in nutrition education.
"Gain" weight at Christmas
Water retention after the binge: following large binges, the concentration of nutrients in the blood (especially glucose and sodium) tends to increase dramatically, favoring the increase in osmotic pressure and the relative increase in plasma volume to maintain homeostatic equilibrium: ergo. ..
the volume of blood plasma and, consequently, that of interstitial fluids tends to increase significantly following large meals consumed at Christmas.
It is also logical that, assuming the restoration of a balanced diet, the faster the excess water is considered, the more quickly it should be disposed of; on the other hand (as often happens) if large meals were CONSECUTIVE, the body would tend to preserve the "sponge" effect until the "normal" daily habits and the desirable physical-sporting activity are restored (a further element favoring the recovery of physiological homeostasis).
Fullness of the digestive tract: obviously it is not simply a question of gastric "totality", which persists only up to 3-5 hours after a hearty Christmas meal. In the adult, the digestive tract (esophagus and pharynx excluded) is about 6.5m long (of which only 25cm belongs to the stomach) and several CONSECUTIVE large meals can fill it more than normal. This means that, by measuring body weight during or in the immediate post-Christmas term, there is the risk of adding the visceral content to the deposit fat.
Fat accumulation: To be honest, fat accumulation also plays an important role in weight gain during Christmas and, contrary to water retention and digestive tract fullness, it is NOT simply a temporary factor; therefore, the restoration of the physiological condition prior to the holidays also includes a certain weight loss (more or less important according to the amount of the deposit).
It is not possible to establish what are the relative percentages of importance in "weight gain during the Christmas holidays (since bioimpedance analysis is also a method of indirect body mass assessment)", however, it is possible to state that variations in some total kilograms (based on the number of days and meals).
"Lose" weight after Christmas
As anticipated, after having "given in" for the Christmas holidays, it is very important to be able to restore the right body weight.
First of all, for methodological correctness, it is essential to evaluate the adipose increase after a few days of normal nutrition to avoid overestimates caused by water retention and the fullness of the digestive tract; in this way it is possible to organize the weight loss more precisely without risking to exceed the calorie reduction.
Let's suppose that a subject weighing 70 kilograms (kg), after a festive "stop" from physical activity associated with overeating induced by Christmas lunches and dinners, has gained 3 kg of real fat (measured after 15 days of normalization and restoration of habits) and that he must lose weight until he regains his initial body composition. To achieve the goal, it is first of all necessary to remember that "optimal weight loss" never exceeds the threshold of 3kg per month but, on the other hand, to be motivating, it should not drop below the 2kg threshold every 30 days, so doing a couple of calculations ...
1) Subject of 70kg → 2) Christmas holidays December 24th: January 1st → 3) weight gain up to 73kg displayed on January 15th → 4) weight loss of 3kg scheduled by February 15th or the end of the same.
Last but not least, the estimate of the amount of energy to be subtracted from the normal one to obtain a weight loss of about 3kg in 30 days (days): if it is true that one kg of fat, not being made up entirely of lipids but also of water and other molecules, is equivalent to about 7000 kilocalories (kcal), in the programmed period it will be necessary to subtract:
7000kcal * 3kg = 21000kcal TOT
...That is to say...
21000kcal: 30 days = 700kcal / day
In conclusion, if the 70-73kg subject has an overall daily energy expenditure (basal metabolism + physical activity and desirable) of 2500kcal TOT (purely hypothetical), it would be necessary to eat no more than:
2500kcal / day TOT - 700kcal / day = 1800kcal / day TOT
NB. Another valid method to calculate the energy requirement useful for weight loss of about 3kg per month is to consume 70% of the energy necessary to maintain a normal weight; using the hypothetical parameter indicated above
2500kcal / day TOT * 70% = 1750kcal / day TOT
Bibliography:
- Levels of Recommended Nutrient Intake for the Italian population (LARN) - Italian Society of Human Nutrition (SINU) -.
