NUTRITION and DIETARY PRINCIPLES

Everyone of us has a basic knowledge of nutrition. But it is not easy to process all the information you need for a healthy diet. At the same time, we all have a certain amount of basic knowledge about healthy eating.

The concept of a diet is generally understood to be a specially designed way of eating which is followed for a certain length of times. This demonstrates the most serious disadvantage of a diet: the energy and nutritional content are often not suited to cover the long-term needs of the human organism, so that whenever a diet comes to an end, the eating habits that were in place before the diet generally take over. Even if a loss of body weight is achieved by a strict diet, most diet do not give any information about how to continue with sensible eating in the future.

To understand that a reduction in body weight of about one pound a day, as achieved by a crash diet, does not mean a loss of fat only, we need to make the following calculation: one gram of fatty food liberates 9 kcals on combustion, whereas by comparison, one gram of body fat produces 7 kcals. The energy content of body fat is lower since the body tissues contain, for example, connection tissue which contributes nothing to its fuel energy. At best, one pound of body fat therefore releases 500 x 7 kcal = 3500 kcal on combustion.

The daily intake recommended by many nutrition institutes for a 25 to 51 year old man is 2400 kcals and for a woman of the same age, 2000 kcals, assuming moderate physical activity.

There are certain eating patterns which have neither the balance of the usual nutritional recommendations nor the short-term nature of a diet. These are described as alternative ways of eating. Among them we include vegetarianism, macrobiotics and the Hays Diet.

Theories on Appetite

What drives the human body to ingest food? There are various theories about this, all of them with a greater or lesser scientific base. The most thoroughly researched of them is the relationship between the feeling of hunger and the blood sugar level. The further the blood sugar level falls, the stronger the feeling of hunger. But the degree of expansion of the stomach is also considered to be a stimulus for food intake. The set-point theory provides another point of view: it holds that stored in each individual's genes is a specific ideal weight and therefore a specific level for fatty tissue. If the stored weight is under or over achieved to any marked degree, the brain manages food intake so as to achieve it. It is also assumed that there is a relationship between food intake and the levels of amino acids stored in the body.

While internal stimuli control food intake (lack of energy and malnutrition), a feeling of hunger occurs to compensate for this lack. On the other hand, external stimuli may lead to uncontrolled food intake.

It is presumably a combination of the focus factors (stomach content, blood sugar and amino acids levels plus the set-point) which control the internal stimulus to ingest food. By chewing for long enough it is possible, through a reverse mechanism in the brain, to achieve a feeling of repletion. However, this only occurs after about twenty minutes of chewing.

If you think about your favorite food, it becomes clear that ingesting food is not controlled only by your body's needs for nourishment. There is also a multitude of external influences such as appetite, enjoyment, boredom, frustration, solitude, irritation, sociability, etc. If all these external influences did not exist food science would be superfluous, as the human organism, controlled by internal stimuli, would ingest only the best combination of food. If all the food we needed were available, food intake would be halted when the internal stimulus cut out. Without social and psychological influences, availability of all the necessary foodstuffs would mean that both under and over eating would be impossible.

TEN RULES FOR HEALTHY EATING

The nutrition wheel shows the various food groups that should fulfill your daily energy needs.

The individual segments indicate the recommended energy value of each group.

By "good food" most people mean taste and enjoyment, by "good diet" they mean health and a good figure. However, food and diet are by no means opposites, and health and a good figure can very easily be combined with taste and enjoyment.

1) VARIETY - BUT NOT TOO MUCH

As there are no foods containing an optimum combination of the required nutrients such as fat, protein, minerals, vitamins, water and fiber, the diet must include the required quantities of the various nutrient groups in order to guarantee optimal provision. The wheel of nutrition provides an easily understandable overview, which combines all the information about the quantities of each foodstuff which should be consumed to achieve a balanced diet. Naturally each group contains some foodstuffs which have a higher rating from the point of view of physiological nourishment and others which have a lower rating. So, in the groups showing cereals and cereal products, we have a slice of toasted bread made from milled white flour.

2) LESS FAT AND FATTY FOODS

Pay special attention to the so-called hidden fat. This includes for example fat in meat, delicatessen meats, cheese, eggs, nuts, cakes, chocolate, etc. Make sure that this hidden fat amounts to no more than 30 to 40 grams a day. To get a feeling for how much fat is hidden, we recommend that you carry out checks to assess this over a few days. This way, you will have information not just on how high your daily energy intake is and how high your fat consumption is, you will also learn whether the combination of the main nutrients meets the recommendations.

3) SPICY BUT NOT SALTY

Your sense of taste will very quickly get used to salty food. If you start eating very salty food for a few days you will then find food with a normal amount of salt very tasteless. At the moment many populations use on average twice as much salt as recommended, that is, ten grams of cooking salt instead of five grams per day. There are now questions about whether some people are more susceptible to increased blood pressure and therefore increased. risk of heart attacks, possibly as an undesirable side-effect of this high intake of cooking salt. Most cheeses, preserves, prepared dishes, snacks, delicatessen meats, cooking aids such as stock cubes, mustard and concentrates are particularly salty. On the other hand, there is very little salt in milk, yogurt, fresh vegetables, meat and herbs. Use fresh herbs for taste. Only add salt after tasting : there is an iodine deficiency, the use of iodine salt is recommended since this can help to prevent iodine deficiency. In any case, our sense of taste changes after a few weeks of low-salt diet, so that we will then experience low-salt foods as pleasantly spicy.

4) NOT MUCH SWEET FOOD

Just as we can form a certain threshold of acceptability for salty food, so too can we for sweet food. A certain dependency on sweet things can develop in this way. While they have a relatively high energy content, sweets have a relatively low nutritional value. Simple sugars and refined sugars are frequently combined with saturated fats. Especially sticky sweets, such as candy, etc., threaten dental health by forming caries. Anyone who eats sweets regularly is absorbing too much energy and is giving up nutritious foods in exchange for sweets with little nutritional value. This, of course, means that the body will be provided with fewer of the nutrients it needs to survive. In addition, sweets offer absolutely no way out of this situation. Even if they contain no energy themselves, they are first of all contributing to raising the level of the sweetness threshold for the sense of taste, and secondly they cannot satisfy the hunger for carbohydrates, because they do not contain any. This is how, when people are hungry and when the blood sugar level is low they often consume more sweet foods that they actually need for their energy requirement. So if you feel like eating something sweet, you should have some fresh or dried fruit.

5) MORE WHOLEMEAL PRODUCT

The consumption of products manufactured from milled white flour mainly reduces the quantities of fiber, vitamins and minerals consumed. These elements, contained in the external layers of whole wheat, are mostly lost when it is milled. As the fiber intake of many people is less than the recommended 30 grams, and as the provision of the B - vitamins and certain minerals is not always guaranteed, we should not do without the benefit of whole meal products in our diets.

6)  A WEALTH OF VEGETABLES, POTATOES AND FRUIT

Fruit and vegetables contain mainly carbohydrates, which are supposed to supply more than half of the energy we consume everyday. In addition to this, fruit and vegetables provide the body with fiber, vitamins, minerals and water. The high water and fiber content mean they have a relatively low energy content. Pulses - like potatoes - have, in addition to their particularly high fiber content, a very high protein content, the value of which is enhanced when combined with cereal or milk products. Even deep-frozen fruit and vegetables can be recommended if, as is now common practice, they are quick-frozen immediately after harvesting. This process preserves vitamins which are often lacking in fresh fruit and vegetables which have generally spent a few days in storage, which causes volatile vitamins to be lost on their way to the store.

7) LESS ANIMAL PROTEIN

Even though animal protein generally has a higher biological rating than vegetable protein, that is, it is more easily utilized by the human organism, sources of animal protein do not only bring benefits. Apart from providing highly rated protein, meat, delicatessen meats and eggs also given us unwanted by-products such as saturated fats, cholesterol, (which can cause gout in high enough concentrations) and salt. This is why meat consumption should be restricted to two or three small portions (maximum 150 grams) per week. Even delicatessen meats (maximum 50 grams) and eggs should not be eaten more than two or three times a week. Instead of eating meat frequently, have saltwater fish twice a week. In addition to having a high protein content, this gives you large amounts of iodine, provided by hardly any other foods. If, addition to this, you combine your vegetable protein sources with other protein rich foods such as milk, milk products or cereals in your diet, you need not fear deficiencies in your protein supply, especially if you are involved in strength training.

8) ENLIGHTENED DRINKING

Drinking can provide the fastest energy replacement without any related feeling of satiation. As this energy has no parallel nutritional value, especially when it comes from lemonades and even alcoholic drinks, it is recommended to cut down on this type of drink as much as possible. In particular, alcohol, which in its pure form supplies about 7 kcals per gram, should never be used to quench your thirst. Not only do large quantities of alcohol have a negative effect on the reflexes and coordination, but if taken regularly, leads in the worst cases to an addiction and then also damages the internal organs such as the liver, kidneys, stomach and intestines, as well as the brain. Since about 1.5 liters of your liquied requirement should come from drinks, the ideal is to meet this need with mineral water and fruit teas. Even though they provide no energy, coffee and black tea can only cover the liquid requirement to a limited extent, as they contain stimulants in the form of caffeine and tea bromides, which can lead to a certain dependency. Fruit and vegetable juices should be watered down, where possible (at least 1:1). In this way, you will not save a lot of energy: juices fruit like this are more easily absorbed by the body.

9) SMALLER MEALS MORE OFTEN

Five smallish meals will not only crank up your metabolism, this will also mean that energy dips during the course of the day have a lesser effect on you (figure 1). So have a second breakfast and an afternoon snack. But as a result, make your main meals smaller than usual so that your total energy intake does not exceed the required level. If your body weight is normal, you could even allow yourself a little late snack after supper.

10) MAKE TASTY AND NUTRITIOUS FOOD

Cook for as short a time as possible and with little water or fat, to preserve the nutrients and flavor of the food. Vitamins are partially soluble in water and are sensitive to heat, oxygen and light. To preserve them, store your vegetables and fruit in a cool, dark place, use them as quickly as possible and never keep them warm for long. In addition, you should wash them before chopping and chop them coarsely so that the surfaces, which can lose nutrients, cover only a limited area. Minerals are also lost in water. Careful preparation not only attains positive results for the nutritional content; it also considerably improves the flavor.

VITAMINS AND MINERALS

Nowadays people are much more familiar with vitamins and minerals as special preparations rather than in their natural form in fruit and vegetables or milk and milk products. Neither vitamins nor minerals supply energy - unlike carbohydrates, fats and protein. Nevertheless, they are included among the essential nutrients, that is, food that keep you alive. As the body itself cannot produce them, they have to be provided in food we consume. Their main task is to regulate a wide range of metabolic processes. In addition to this, some minerals are used by the body as building blocks.

FUNCTIONS AND PROVENANCE OF THE MAIN MINERALS

MINERAL

Sodium

Potassium

Magnesium

Calcium

Phosphorous

Chloride

Iron

Iodine

Zinc

Fluoride

Copper

Selenium

Manganese

Cobalt

FUNCTIONS AND PROVENANCE OF THE VITAMINS

VITAMINS

Vitamin A

Vitamin D

Vitamin E

Vitamin K

Vitamin B1

Vitamin B2

Vitamin B6

Vitamin B12

Vitamin C

Nacin