In order to maintain your body weight, energy intake with foods must match your individual needs, depending on age, sex and level of physical activity; calories exceeding needs accumulate in form of fat that will deposit in various parts of the body (typically in men, as in postmenopausal women, the accumulation area for excellence is abdomen).
An example: let’s assume an energy requirement of 2000 kcal with an intake of 2100 kcal. The extra 100 kcal could result from 30 g of pasta or 35 g of bread or a 25 g package of crackers or 120 g of potatoes or 10 g of oils from any source etc., not a particularly large amount of food. This modest calories surplus, if performed daily for one year leads us to take:
100 kcal x 365 days = 36500 kcal/year extra calories compared to needs.
Since a kilogram of body fat contains approximately 7000 kcal, if we assume that 36500 kcal in excess accumulate exclusively in form of fat (very plausible approximation), we obtain: 36500/7000 = about 5 kilogram of body fat.
So, even a modest daily calorie surplus, over a year, can lead to a substantial body weight gain in the form of fat mass.
This example shows the importance of estimating with accuracy our daily energy requirements.
Split daily caloric intake into multiple meals
Let’s assume that daily caloric requirement to maintain body weight is equal to 2000 kcal.
Is it the same thing if they are consumed in just two meals, maybe dividing them in half between lunch and dinner, or is it advisable to take three to five meals during a day?
In order to mantain body weight, the best choice is to divide calories into five meals: breakfast, lunch and dinner, the most abundant, plus two snacks, one on mid-morning and the other on mid-afternoon. Why? There are various reasons.
- Consuming only two meals during the day, lunch and dinner or breakfast and dinner, it is likely to approach both meals with a hunger difficult to control; we eat what we have on our plate already thinking about what else to eat, having the feeling of not being able to satisfy the hunger. We eat, but there is always room for more food. Among the reasons for this there are too many hours between meals. Two examples:
dinner at 8:00 p.m. and, the next day, lunch at 1:00 p.m.: the interval is 17 hours, more than 2/3 of a day;
breakfast at 7:00 a.m. and dinner to 8:00 p.m., 13 hours have passed, most of which are spent in working activities and therefore more energy-consuming than hours of sleep.
Then, drops in blood sugar levels (glycemia) can also occur: liver glycogen stores, essential for maintaining normal glycemia, with time intervals between meals previously seen, can easily reach values close to depletion.
Therefore, by splitting the daily caloric intake into two meals, it is most likely difficult to meet the target of assuming 2000 kcal (the suggested daily calorie intake).
- The concentration of too many calories in a single meal may promote the increase of plasma triglycerides, the excess of which is linked to the onset of cardiovascular disease.
- When accumulating almost all or all of the calories in just two meals we are likely to grow stout, have feelings of bloating and getting real digestive problems due to excess of ingested food, not to mention that could occur even a postprandial sleepiness or difficulties in getting asleep.
Physical activity has a central role both in maintaining the reached body weight and in the loss of fat mass.
Make physical activity on a regular basis has several advantages.
- If exercise is conducted on a regular basis and is structured in the proper way, is possible that, even without appreciable changes in weight, a redistribution of fat occurs between fat mass, which drops, and free fat mass, which, on the contrary, increases. Such a result can’t obviously be reached by simple walk; we need a specific training program, better if planned by a professional, and a proper diet, always of Mediterranean type.
- We protect muscle mass (and as suggested in point 1. we can also increase it).
- We maintain a high metabolism.
- Muscle burn energy during and especially after exercise.
- The body is toned.
- Appetite is controlled more easily.
- Making physical activity on a regular basis makes the prevention of weight gain easier, due to the inevitable “escapades” (indulging in a bit of chocolate, an ice cream etc..).
Giampietro M. L’alimentazione per l’esercizio fisico e lo sport. Il Pensiero Scientifico Editore. Prima edizione 2005
Haskell W.L., Lee I.M., Pate R.R., Powell K.E., Blair S.N., Franklin B.A., Macera C.A., Heath G.W., Thompson P.D., Bauman A..Physical activity and public health: updated recommendation for adults from the American College of Sports Medicine and the American Heart Association. Med Sci Sports Exerc 2007;39(8):1423-34. doi:10.1249/mss.0b013e3180616b27
Mahan L.K., Escott-Stump S.: “Krause’s foods, nutrition, and diet therapy” 10th ed. 2000
Shils M.E., Olson J.A., Shike M., Ross A.C.: “Modern nutrition in health and disease” 9th ed. 1999