Calories (kcal) are provided by 3 types of nutrients in food: carbohydrates, fats and proteins. Carbohydrates have to supply 50 to 55% of daily energy, proteins 10 to 15% and fats 30 to 35%.
These macronutrients are essential every day. Another nutrient provides energy: alcohol, but unlike the other 3, it's not essential to the body. That's why it isn't part of the recommendations.
In addition to the 3 main macronutrients, the body needs micronutrients every day, nutritional elements that don't provide energy but which are essential for correct function of the body: these are vitamins, minerals and water.
CarbohydratesThese nutrients should represent 50 to 55% of the daily energy in a balanced diet.
We distinguish foods rich in complex carbohydrates (starchy foods) from those rich in simple carbohydrates (sugar, fruit, sweets, etc.).
In a balanced diet, foods rich in complex carbohydrates should form the larger part of the daily diet.
Carbohydrates contain glucose, which is the preferred fuel of muscle as the energy supply ; energy derived from glucose is the easiest for the muscle to use. The body can store a certain amount of glucose, in the form of glycogen in the muscles and liver. The body's glycogen reserves are low (250 to 400 g) and practically exhausted at the end of 30 to 90 minutes of exercise, depending on its intensity.
The glycaemic index (GI) of a food is a measure of its relative ability to raise glycaemia (the blood sugar level). The lower the GI of a food, the slower but more prolonged the availability of the glucose over time; and inversely, the higher the GI, the more rapidly but more transiently the glucose is available.
Knowing the GI of a food is important for good management of the carbohydrate reserve before, during and after exercise.
- low GI (<40) : dried vegetables (lentils, etc.), fruits such as apples or oranges, milk, yoghurt, fructose, dried apricot, etc.
- moderate/average GI (40 to 70) : pasta al dente, rice, bread, fruits such as bananas or grapes, most vegetables, chocolate, ice cream, potatoes, cereal bars, raisins, etc.
- high GI (> 70) : glucose, sweeter vegetables such as carrots or beetroot, honey, sweetened cereals for breakfast, waffles, etc. 1a/ Fibre
FibreFibre plays functional roles in the body and do not contribute to energy intake, but they are classified as carbohydrates because, by virtue of their biochemical structure, they are carbohydrate molecules.
- have the same nutritional benefit for sportsmen and women as for the population in general. They should preferably be eaten outside periods of competition and in the same quantities as recommended for the population in general (at least 15g/day, ideally 25 to 35 g/day). Causes of constipation are common: stress, unbalanced (excess of "processed" foods) or restricted diet , travelling. Other than the choice of so-called "laxative" water. Increasing and monitoring fibre intake is justified.
- have a role in gastro-intestinal emptying.
These nutrients should represent 30 to 35% of the daily energy in a balanced diet. Foods with the most fats are fatty substances (oils, butter, margarine, etc.), but fats are also found in some other foods (cooked meats, fatty meats, fatty cheese, fried food, pastries, etc.).
Fatty acids (constituents of fats) can also be used by the body to supply energy ; the fatty acids used usually come from the adipose tissue, however they cannot be used by the muscle during intense exercise.
Some extreme sports (trekking in cold countries, trips into the high mountains, etc.) can lead to an increase in fats consumption. Foods rich in fats can help to respond to these situations.
ProteinsThese nutrients should represent 10 to 15% of the daily energy in a balanced diet. Proteins are essential constituents of the body, especially the muscles. The foods with the most protein are meat and its equivalents (fish, eggs, etc.), dairy products, dried vegetables and soya.
For sports requiring a loss of body fat and/or an increase in muscle volume, proteins play a major role in creating muscular mass, but also in compensating for muscle loss and repairing damaged muscles after exercise.
Generally speaking, the daily diet is enough to deal with an increase in protein needs (normal intake of 1 g of protein /kg body weight /day, which can be increased to 1.5 g or 2 g of protein/kg/day for long duration sports. But for some sports such as body-building, power sports, etc. that can require 2-2.5 g of protein/kg/day, protein supplements can be considered.
Increasing protein consumption to gain muscular mass must in any case last a maximum of 6 months and must not exceed 3 g of protein/kg/day (to avoid liver and kidney problems). To be effective, this increase in protein consumption must obviously be associated with specific training, without resorting to anabolic products.