Stewed lentils or spaghetti with tomato sauce are two examples of traditional dishes rich in carbohydrates. These nutrients so essential for the human body are also present in other pastas and legumes, bread, grains, vegetables, fruits, sugar and sweets. They also represent the body's main source of energy.

This energetic potential is precisely one of their handicaps, and the reason they have vanished from many dinner tables. Many recipes based on flour or legumes have been ditched because of the mistaken notion that, for example, bread or chick peas are fattening. Many nutritionists and endocrinologists are trying to rescue them for two powerful reasons: they are healthy and not all that fattening.

What are they?
Carbohydrates are chemical compounds formed by carbon, hydrogen and oxygen. They all share the same basic structure, but there are different kinds depending on the complexity of their chemical formula.
- Monosaccharides: these are the simplest ones, which include glucose, present in fruit and honey. Glucose is the compound into which complex carbohydrates are transformed. Monosaccharides also include fructose, which after being absorbed by the intestine goes into the kidney and is metabolized into glucose.

- Disaccharides: the result of the joining of two monosaccharides, an example being sucrose (common sugar) and lactose, the sugar contained in milk.

-�Polysaccharides: the result of the union of several monosaccharides. They are more complex to digest. One example is starch, the energy reserve of vegetables, found in grains, tubers and legumes.

-�Glucogen: Serves as the main carbohydrate reserve of the human body, and stored in the liver and muscles. Liver glucogen is used mainly to keep up levels of blood glucose. That of the muscles is an essential source of energy during physical exercise, especially if it intense and sustained.

The Fundacion Jimenez Diaz in Madrid says carbohydrates should make up between 50 and 60 percent of a person's caloric intake. Compared to proteins (meat and fish), the other main source of calories in our diet, carbohydrates cause fewer health problems.

Research has shown that proteins contribute more to obesity, hinder kidney function and can lead to calcium loss when consumed in excess. Not to mention the damage that animal fat causes to the heart and circulatory system. Furthermore, comparing the same amount of carbohydrates and fat, the former provide twice as much energy and also fiber (in the case of legumes and vegetables) and glucose, the only food that nourishes the brain.

They are not all that fattening
One of the most important studies on carbohydrates, the so-called Carmen Study,� focused on 400 overweight people who changed their diet for a 6-month period. They consumed the same amount of kilocalories. But while one group continued eating fats, another replaced them with complex carbohydrates and other with simple ones.

The result was that the ones who ate carbohydrates lost two kilos, while those who stuck with fat saw their weight rise or remain stable.

One of the reasons carbohydrates are less fattening than fat is that the body burns them up faster. When a person does significant physical exercise, the first things burned up are carbohydrates. So athletes regularly consume carbohydrates.

On the other hand, lipids are transformed much more easily into body fat. They are reserved for use only when there are no more carbohydrates to turn to. As if this were not enough, the body uses 12 percent of its energy to metabolize carbohydrates, whereas it uses 7 percent to do this with fats. Want another reason to consume carbohydrates as a weight-controlling food? They are more filling than lipids, so it takes longer to feel hungry again. Plus they are a source of fiber and relieve constipation and the bloated sensation it causes.

Diabetes and good mood
Some people say that carbohydrates, especially simply ones, such as sugar, cause diabetes. Not only is this false, but diabetics can consume carbohydrates as long as they keep an eye on the rest of their diet. The big problem for diabetics is obesity, often associated with this illness. Controlling it depends on moderate consumption of fat.

Many studies show that a diet rich in carbohydrates has a sedative effect and can help fight disorders such as insomnia. This happens because carbohydrates raise levels of serotonin in the brain. This chemical regulates sleep and mood (people with depression suffer from abnormal levels of� serotonin). Serotonin is also at the root of some experts' recommendation that women with premenstrual syndrome increase their consumption of foods rich in carbohydrates, both before and after their period. It helps fight against symptoms of sadness and irritability, which are common during their stage of the female menstrual cycle.