Table of Contents
Ideal body weight and active lifestyle
Eating healthy means first and foremost meet your needs energetic and nutritional.
Our body weight keeps constant when we are in one state of energy balance in which the calories we enter through food are equivalent to the calories we spend. The energy intake derives from the so-called macronutrients, or nutritional elements that must be introduced in large quantities (hence the definition of “macro”) because they represent the most important energy source for the organism. The macronutrients are:
- proteins;
- carbohydrates;
- the fats.
L’food intake it is regulated by various factors (psychological, social and environmental) which interact with each other in a complex way. The energy expenditure instead it represents the energy used for the maintenance of physiological and biochemical activities: in conditions of rest, the amount of energy expended by our body is given the name of basal metabolism.
To know ours total daily energy expenditure (Total Daily Energy Expenditure), the energy expended must be added to the basal metabolic rate:
- during the digestion and absorption processes food (diet-induced thermogenesis);
- for regulate body temperature (adaptive thermogenesis);
- for carrying out all physical activities (thermogenesis induced by physical activity).
A healthy diet, therefore, is able to guarantee the maintenance of a energy balance.
In the face of a calorie excess, the body weight inevitably increases and the expansion of adipose tissue leads to a greater risk of suffering from chronic-degenerative diseases (diabetes, cardiovascular diseases, neurodegenerative diseases, oncological diseases). Conversely, a energy deficit leads to a reduction in body weight with loss of muscle mass and deterioration of the state of health as is typical of states of malnutrition.
If we are in an overweight condition it will be necessary reduce energy input at the same time increase energy expenditure through daily physical activity. One of the most effective approaches is based on a dual strategy:
- reduce consumption of foods dense in energy but poor in nutritional value, such as industrially derived foods that abound in saturated fats and simple sugars but fail to provide adequate amounts of vitamins and antioxidants;
- prefer the consumption of food low energy, such as those of vegetable origin characterized by a high fiber content and rich in vitamins, antioxidants and mineral salts.
More fruit and vegetables
Eating healthy means consuming more portions of fruit and vegetables throughout the day. Fruits and vegetables have the characteristic of having a low energy density. This means that they provide few calories per unit of weight and volume.
Let’s see the main components of these foods and the beneficial effects of consuming fruit and vegetables for the body.
Fibers
By eating fruit and vegetables we can reach the earlier sense of satiety, a factor linked to the high content of soluble and insoluble fibers. Since we do not have the enzymes capable of breaking down dietary fiber into simple sugars, the fibrous component of fruit and vegetables it arrives unaltered at the level of the last section of the intestine and here it becomes nourishment for colonic bacteria: these microorganisms are capable of converting dietary fibers into molecules known as short-chain fatty acids, components that interact with specific receptors present at the level of the intestinal mucosa inducing a sense of satiety.
Dietary fibers can be divided into soluble and insoluble:
- cellulose, hemicellulose and lignin are water insoluble fibers and act mainly on the functioning of the gastrointestinal tract promoting intestinal transit and stool evacuation. These fibers, therefore, counteract the phenomenon of constipation;
- the soluble fibers are pectins, gums and mucilages. These swell when they come into contact with water and form a gel which, in addition to increasing the volume of stool, it also limits the absorption of simple sugars and dietary fats. With this mechanism, soluble fibers help keep blood sugar and cholesterol levels low.
Vitamins, minerals and antioxidants
We must not overlook the fact that fruits and vegetables are an important source of vitamins:
In addition to providing vitamins, fruits and vegetables are also important sources of mineral salts.
The healthful effects of an adequate consumption of fruit and vegetables are also linked to the presence of antioxidant molecules, such as resveratrol in grapes, epigallocatechin gallate in green tea, quercetin in fruit, allicin in garlic. These are molecules capable of counteracting the action of free radicals.
Benefits
Numerous epidemiological studies document that a diet rich in fruit and vegetables, low in saturated fats and simple sugars, is able to prevent the onset cardiovascular diseases, diabetes, diseases of the digestive system and tumors. Based on what has been said so far, eating healthy means guaranteeing oneself adequate intake of dietary fiber, vitamins and antioxidants. This goal can be accomplished by hiring at least 5 servings a day between fruit and vegetables (Five-a-Day).
Under the guidelines for healthy eating (Ministry of Health, 2019) the five recommended portions have been divided into two portions of vegetables which we could associate with the two main meals (lunch and dinner) and in three portions of fruit. It is important, however, to underline the fact that the five portions must be understood as minimum quantity.
The other important indication is that of work as little as possible fruit and vegetables in order to maintain the nutritional qualities unaltered. The advice regarding fruit is to eat it as it is, avoiding the consumption of fruit juices as much as possible. In general, the transformation processes lead to a reduction in the content of some nutrients. Certainly the nutrient that is most affected by the transformation processes is dietary fiber. There reduced amount of fiber typical of refined foods and industrial products, it reduces the satiating power. If we eat an orange, we feel a certain sense of satiety. If we drink a juice, the effect on satiety will be far less.
More whole grains and legumes
Cereals and legumes represent a cornerstone of the Mediterranean Diet. I’m an important one source of nutrients and energy. Many of the traditional Italian food recipes are based on a combination of cereals and legumes (see for example pasta and beans, pasta and chickpeas, rice and peas).
Between cereals most in use we remember rice, corn, barley, sorghum, millet, oats, rye and spelled. Pseudo-cereals (which do not belong to the family of grasses but because they produce seeds that can be used like those of grasses, they are referred to with the term of pseudo-cereals) are instead buckwheat, quinoa, amaranth. Like cereals, pseudo-cereals are also sources of carbohydrates, proteins and fibers, unsaturated fats, B vitamins and mineral salts.
THE legumes they provide starch, dietary fiber, proteins of moderate biological value, vitamins and mineral salts, substances with antioxidant action. They may be available fresh or dehydrated. They are beans, chickpeas, lentils, cicerchia, peas and broad beans. Green beans are also legumes but are assimilated to fresh vegetables since the seeds are in an early state of ripeness and, unlike other legumes, green beans have a significantly lower content in proteins and energy and a high content in water. In other words, they have characteristics more similar to those of fresh vegetables.
Legumes are one good source of protein but it should be specified that the proteins of vegetable origin have a lower quality than those of animal origin. In particular, sulfur amino acids and specifically methionine and cysteine are less represented in legumes. Due to the presence of molecules with anti-nutritional activity the legume proteins are rather resistant to the digestive action of enzymes.
The recipes that involve the use of cereals and legumes, typical of the Mediterranean Diet, have a higher protein quality than that of legumes alone or cereals only due to an effect linked to the complementarity of the amino acid composition. In fact, legumes are deficient in methionine and cysteine but are abundant in lysine. On the contrary, cereals are rich in methionine and low in lysine.
In order to achieve a varied and balanced diet it is recommended to take three to five portions of legumes per week.
Saturated and polyunsaturated fats
Together with carbohydrates and proteins, fats represent one of the three macronutrients. The main function of fats is that of accumulate energy: one gram of fat, in fact, provides 9 kcal. The fats present in the meal we consume, allow theabsorption of fat-soluble vitamins (vitamin A, vitamin D, vitamin E, vitamin K) and carotenoids. Plus, they make our food tastier since amalgamate the aromatic substances able to give smell and taste.
Triglycerides and fatty acids
Fats are chemically complex substances: the most common in foods are triglycerides, consisting of a glycerol molecule and …
