Nevertheless, for the digestion of fruits the body needs much more calories than to contain itself. The reason is that the process of extracting calories from these foods is more complex and, consequently, the body is wasting more energy than necessary. You should not, of course, eat only these foods, because this will lead to the lack of essential nutrients that are conducive to health.
Low-calorie fruits include: apples, raspberries, cherries, grapes, kiwi, peach, strawberry, melon, apricot, mandarin, orange, lemon, grapefruit. Caloric fruits - banana, pear, pineapple, melon, quince and others.
The content of calories in some fruits (calculation per 100g.):
Lemon - 19 cal .;
Orange - 37 calories;
Cherry - 54 cal .;
Green apple - 41 calories;
Grapes - 60 cal .;
Mango - 57 cal .;
Peach - 45 cal .;
Malina - 37 cal .;
Bilberry - 57 cal .;
Apricots - 49 cal.
When is it better to eat fruit - before or after eating?
When you consume fruits in the morning before eating, they saturate the body with a large amount of fast carbohydrates, vitamins, minerals, organic acids and normalizes the pH balance. We deliver with their help in the body water and fiber, activating the "lazy" intestines, clearing it of any residues and debris. If you eat fruit after eating - the content of glycogen sugars in them will restore the balance of glucose in the body. The liquid will help them to recover energy costs. To minimize the risk of obesity - it is better to eat fruit in the morning, in the period until 12 noon.
Many people give up fruit, because the content of fructose in them scares a quick set of excess weight. Of course, a lot of fructose can cause an excess of glycogen in the liver and be deposited as fat. On the other hand, fiber and other nutrients in fruits give more benefit than any other food product. And in the obtaining of substances useful for the activity of the organism, the goal is to consume the products! Fructose is the main source of carbohydrates in vegetables and fruits. Most of it is contained in nectar flowers, plant seeds and bee honey.
What is fructose?
Carbohydrates can be divided into three groups: monosaccharides, oligosaccharides and polysaccharides. All carbohydrates are in a solid state and have the same qualities. Their molecules consist of three elements: carbon, hydrogen and oxygen. Monosaccharides (glucose and fructose) are colorless crystalline substances, readily soluble in water and sweet in taste. Sweetness arises from the accumulation of a large number of hydroxyl groups in their molecules. When heated, they melt, burn and eventually become the cause of charring with the release of water vapor.
In the physical reference, fructose is characterized as a substance that has a sweet taste and is soluble in alcohol. Fructose has the same qualitative and quantitative composition and molecular weight as glucose. Fructose and glucose can be fermented by various enzymes. Depending on the type of fermentation can produce more lactic acid, acetic acid, alcohol. Fructose is twice as sweet as glucose. She is absorbed better, even by people with diabetes. Therefore, it is prescribed for such patients.
How does fructose work in the body?
Fructose creates a false sense of hunger, which leads to overeating and weight gain, respectively. Its sweetness is 1.4 times higher than sugar, but it is not suitable for carbohydrate load. In the human body, fructose is easier to digest than white sugar, because it is a simple chemical compound. Fructose is absorbed more slowly than glucose in the digestive tract. A large part of it is converted in the liver into glycogen. Fructose is more efficiently incorporated into the conversion process and does not require insulin for cell uptake. It is a dietary product and is important in the body, for the most part, because of its sweetness. In small amounts of fructose, you can sweeten foods and drinks, lowering the intake of carbohydrates. The glycemic index of fructose is about 30, and is therefore particularly suitable for people suffering from diabetes.
Studies have shown that fructose reduces insulin sensitivity in the body, affects the metabolism of fats in it. These changes increase the risk of cardiovascular disease. It was found that the consumption of fructose promotes the accumulation of fat mainly around the internal organs and to a lesser extent affects the subcutaneous layers. Doctors say that a huge amount of fructose in combination with a high fat content can lead to resistance to leptin, so it will be difficult to maintain a balance between food intake and the energy needs of the body. According to some experts, fructose during consumption of fruits and vegetables can cause resistance to leptin in healthy people, regardless of the amount of fruit eaten.
Fructose is a natural substitute for sugar. Absorbed by the body completely and, like ordinary sugar, gives energy. In general it is considered safe, but, unfortunately - calories.
Advantages of fructose
- 30% less calories than sugar;
- It has less effect on blood sugar, which is acceptable for some patients with diabetes mellitus;
- Fructose is one of the few sweeteners that do not contain preservatives and, therefore, is used to prepare diabetic jams and jams. If the usual sugar is replaced by fructose, then the baking lasts longer is soft and fluffy.
- Accelerates the breakdown of alcohol in the blood.
Disadvantages of fructose
- In large quantities can increase the risk of cardiovascular diseases (safe dose - no more than 30-40 g per day);
- Creates a false sense of hunger, which contributes to the emergence of excess weight;
- Accelerates the aging process - according to a study by Israeli scientists in mice.
- High intake of fructose can lead to impaired glucose tolerance and impaired insulin resistance. Both these metabolic disorders are associated with the absorption of insulin and can affect the development of the disease.
- Fructose can cause a strong allergy - intolerance to fruit sugar. With this disease a person can not eat fruits and vegetables at all, as well as drink drinks on their basis.
Having learned how much sugar contains fruits, you can create your own healthy diet.
How much fructose in various fruits (for fruits of medium size)
Pear - 11 g;
Orange - 6 g;
Bunch of cherries - 8 g;
Apple - 7 g;
A bunch of grapes (250 g.) - 7 g;
Slice of watermelon - 12 g;
Peach - 5 g;
A handful of raspberries (250 g.) - 3 g;
A handful of blueberries (250 g.) - 7 g;
A cup of finely chopped pineapple (250 g.) - 7 g;
Nectarine - 5 g;
Kiwi - 3 g;
Melon (about 1 kg.) - 22 g;
A handful of strawberries (250 g.) - 4 g;
Banana - 9 gr.
The main part of fructose is responsible for the metabolism in the liver. There it is converted into glucose derivatives and stored in the form of glycogen. The ability of the liver to convert fructose is severely restricted, and this is good because when it starts to convert in high doses, it can be converted to fat. This is typical for people with high lipid levels in the blood or with a high degree of insulin resistance.
The level of fructose in the blood does not directly depend on the hormonal balance. Its content does not cause a rapid increase in blood sugar levels. And this is a big plus, especially for diabetics. But on the other hand, a large amount of fructose can lead to the accumulation of excess fat. There are problems associated with high intake of fructose. One of them is the possibility of ending its disintegration. It still accumulates in the intestines, but it is not digested. Hence - a bulging belly, flatulence, stomach upset. It is believed that 30-40% of people have such problems. There are also more sensitive people who can not absorb fruit sugar (fructose) in general. Excessive consumption of fruit can lead to spasms in the abdomen, pain and diarrhea.
Fructose does not cause the release of insulin and leptin - hormones that help suppress appetite, and does not inhibit the formation of hormones that stimulate hunger. Therefore, we say that its uncontrolled consumption contributes to weight gain.
It is wrong to think that we should stop eating fruits and vegetables. Everything said here about the damage to fructose makes sense only if it is in large quantities. The use of fruits every day in large portions can even cause an energy imbalance, and may cause so-called "fructose intolerance".
We all know how common sugar is harmful to health, which (not without reason) is often called "white death." However, scientists warn that fructose is often not only not safe, but can even cause much more harm to the body. Because in practice, most of us consume food only with sugar substitutes, such "fashionable" lately. Thus, the level of fructose in the blood is off scale, the liver does not cope with the processing of fructose and the body begins to refuse. Over the past 30 years, manufacturers are gradually replacing conventional sugar and sugar substitutes - fructose, adding to the production of corn syrup, which is made from cornstarch as a result of many industrial processes. Its ability to increase the strength and sweetness of products is used in the industrial production of very large companies whose products consumed around the world in large quantities. In addition, corn syrup improves the quality and flavor of bakery products and is therefore used in the preparation of cakes, pastries, cookies, breakfast cereals. In addition, corn syrup is much cheaper than the production of other sweeteners, and therefore preferable. In a word - fructose, which is sold in stores - it's far from sugar, obtained from fruits. It is obtained by complex technological processing of potatoes or cornstarch and additional chemical treatments. In the end, it turns out the same "fruit" sugar, which is used in many foods and drinks.
The question is often asked: "If I want to lose weight, do I have to give up fruit?" Nutritionists and fitness enthusiasts firmly stand in the position of protecting the consumption of fruit as a product with zero fat content. Others use these products very rarely. There is no exact formula for the regular consumption of fruit. Conclusion: it is useful to eat fruits and vegetables, as they contain easily digestible and valuable fruit sugar, but they need to be used moderately, while observing the appropriate dietary and sporting regimen.