Dispelling some myths about nutrition
One of the ways in which one should not get in shape after the holidays is certainly to resort to extreme diets motivated by guilt. Fasting and the arbitrary exclusion of certain foods are, however, common expedients resorted to by those who want to lose weight quickly.
Sugar, but also complex carbohydrates are often the big suspects for those who want to lose weight: correctly, a single gram of refined sugar (sucrose) is almost equivalent to 4 Kcal. But what would many people think if we said that sugar and carbohydrates are not the nutrients to be excluded?
Carbohydrates are the main part of a healthy diet
The Ministry of Health guidelines do not indicate the exclusion of any macronutrient. All nutrients contribute to a healthy diet, according to balances appropriate to the physical activity being performed and the food availability of a geographical area. Grains and vegetables are an abundant source of energy, ecologically sustainable and less hazardous to health because free of those potentially carcinogenic by-products derived from cooking meat, for example.
The trend in some slimming diets, such as the ketogenic diet, involves a diet low in carbohydrates and richer in fats. While these diets may be effective in the short to medium term, they risk fostering many misconceptions about food.
Carbohydrates are not a danger and it is not true that ‘flours convert to sugar’ (see next picture).
The secret is the energy balance
What determines whether we gain or lose weight is the energy balance (over the medium term, a week for example) if we consume more calories than we take in. Carbohydrates are not the largest source of calories, as much as fat.
- Fats 9Kcal/gram
- Protein 4 Kcal/gram
- Carbohydrates 4Kcal/gram
The difference is the feeling of satisfaction, which is less when eating carbohydrates, and the fact that they are always ‘seasoned’: bread with jam (sugars), pasta with sauce (of animal or vegetable fats) etc. Thus increasing the energy value of a single meal.
The metabolic value
Carbohydrates, with the exception of insoluble fibres (2 Kcal/gram), have a higher metabolic value than proteins, i.e. they are easier for the body to utilise and can easily constitute an excess. Proteins, on the other hand, play more of a functional than energetic role for the body and are therefore preferred by bodybuilders and athletes who value muscle tone. Studies confirm that a high protein intake improves body composition.
Nevertheless, glucose derived from carbohydrates (that famous sugar allegedly hidden in flour) is the body’s preferred energy source, especially the brain, and we cannot do without it or hope to train or work at the same intensity without it.
Diet supplements
For those seeking to control their macronutrient intake, nutritional supplements – ‘clean’ sources such as protein concentrates, maltodextrin gels, etc. – are therefore helpful. They help us assess the amount and type of energy delivered to our bodies, in an economical way (a kilo of milk protein costs less than the equivalent in steak and has less fat).
In addition, specific supplements can help us take micronutrients during a diet that has been low in vitamins or minerals or certain amino acids (for a short period).