Chemical composition and energy value of products

2024 Author: Isabella Gilson | [email protected]. Last modified: 2024-01-18 00:50

In a he althy diet, one of the main criteria for nutritionists is the energy value of products, which reflects the level of usefulness of each type. It is measured in calories. These units are the amount of energy that a person receives from food. A sufficient amount of calories helps to restore good spirits and maintain peace of mind during the working day.

Different degrees of usefulness of certain dishes allows you to create a daily diet in such a way that the body not only gains a sufficient amount of necessary calories, but also receives a full amount of vitamins and minerals. Nutrition experts advise when choosing products in the store, at the same time pay attention to their energy value and chemical composition.

For what purposes does the body spend energy

Most people tend to think that we need calories only for mobile activities. However, scientists have found that approximately 65-70% of allThe amount of energy obtained from food helps the body maintain the normal course of physiological processes: thermoregulation, sleep, digestion of food, the work of the heart and blood vessels, skin regeneration, the formation of new cells, the growth of nails and hair, and many others. In addition to providing the basic energy requirement necessary for the full functioning of the organs, we need calories for:

• Maintaining habitual body movements during daily activities.
• Intensive exercise - for physical labor or strength training.

Knowing the total energy value of foods eaten per day, you can calculate how much the body spends on natural needs, and how many calories it needs to burn for weight loss, in order to eventually get a negative balance.

Specialists in sports nutrition have found that our contemporary consumes approximately 25-30% of the energy consumed from food for physical activity. To maintain he alth and an ideal figure, nutritionists recommend increasing this parameter to 40%. Kilocalories that a person has not spent during the day are deposited in the fat depot at the waist, on the sides and other problem areas.

What are calories and kilocalories

Food calories represent a certain amount of energy released by the body from food during digestion and assimilation. The calorie content of meals or individual products is the potential energy charge that a person receives if the food is completely digested.

Calories are units used to measure the energy content of food. It is known that a food calorie, in contrast to the unit of heat of the same name used in a scientific context, contains 1000 times more energy. That is why nutritionists and adherents of a he althy lifestyle, when mentioning kilocalories, often omit the prefix “kilo”, talking about the effectiveness of a particular food product. In European countries, a kilocalorie is denoted as Kcal, in the USA it is customary to reflect the unit of energy value of food products by the term calories, or abbreviated as cal.

How to determine the energy potential of food and calorie consumption in humans

Scientists, examining the caloric content (energy value) of food, burn food in a calorimeter and count the amount of heat released into the water bath surrounding the device. They found that one calorie is enough to heat 1 liter of liquid by 1 °C. For example, the energy equivalent of a pie (150 cal) allows you to heat 150 liters of water by 1 degree or bring 1.5 liters of liquid to a boil. In another measuring system, the amount of energy value of food is calculated in kilojoules. It is believed that 1 kilocalorie and 4.184 kJ are identical values, as well as 1 kilojoule (1kJ) and 0.238846 cal:

Food Ingredients	For 1g product
	Kcal	KJ
Proteins (proteins)	4, 10	17, 1
Fats	9, 30	39
Carbohydrates	4, 10	20, 1
Fiber	1, 9-2, 0	8, 10
Alcohol	7, 2	26, 1
Sweeteners	2, 5	10, 2
Citric acid	2, 25	9, 1

To determine the intensity of a person's metabolism, he is placed in a ventilated chamber with reliable thermal insulation. A constant temperature is maintained inside the room, and the heated air is pumped through pipes into a reservoir of cold water due to the heat generated by the body of the test subject. So it was found that the daily energy requirement of a person whose work is associated with a sedentary lifestyle is approximately 2000 kcal.

Daily calorie intake of food consumed

A person's daily need for calories, according to the norms adopted in European countries, for a man of average build varies within 2500 units, for a woman - 2000 units. In addition to gender differences, it depends on the weight, age, height, metabolic rate and lifestyle of the person. In 1919, scientists from the Carnegie Institution in Washington derived the optimal formula, named after the authors - Harris and Benedict. With its help, the calculation of the level of basic metabolism for men and women was performed based on biometric data:

The results of this calculation show how many calories per day a person needs to receive fromfood or what should be the total energy value of foods to meet their basic needs.

Correction of a person's daily energy requirement

Depending on the type of work performed, the amount of calories needed for a person (per 1 kg of body weight) also varies:

• Mind work: 30-50 kcal.
• Light work: 30-40 kcal.
• Hard manual labor or strength training: 40-50 kcal.

Using the coefficients of physical activity, you can most accurately determine the individual daily energy requirement:

Physical activity (per week)

Coefficient	Volume
1, 2	Minimal or no load
1, 38	3 medium load trainings
1, 46	5 medium load trainings
1, 55	5 intensive workouts
1, 64	Daily loads
1, 73	Intensive training seven days a week or twice a day
1, 9	Professional sports or heavy physical labor

For those who wish to lose weight

Nutritionists warn that the ratio of calories consumed daily from food and spent in the processvitality must be zero or negative. Otherwise, when the first prevails over the second, metabolic processes are disturbed in the body and the person gains weight. Those who want to lose weight need to reduce the calorie content of the daily diet by 300-500 kcal. In order to burn 1000 g of fat, you need to spend at least 7700 cal. Nutritionists consider getting rid of 2-4 kilograms within a month as optimal weight loss (this mass does not include the amount of water removed from the body during training). To speed up the process of thermolipolysis and spend calories at the expense of fat reserves, it is necessary to reduce the calorie content of the daily diet.

To do this, when visiting supermarkets, you should pay attention to the energy value of products and composition. It must be taken into account that fats can cover only 30% of a person's energy needs, while 58% of the vitality is provided by carbohydrates. Products rich in these organic substances are very high in calories: dried fruits successfully compete with fatty meats in terms of energy value. At the same time, it must be remembered that the diet of a modern person is usually oversaturated with fats and hidden sugars, so the proportion of foods rich in fats should be reduced, redistributing it in favor of fresh vegetables and fruits, mushrooms, legumes, and other vegetable products containing complex carbohydrates..

Energy and nutritional value of products

The nutritional value of each product includes the full range of its useful properties: energy, biological,organoleptic, physiological, as well as good quality and digestibility. Calorie content is directly related to the amount of certain nutrients contained in food: fats, proteins, carbohydrates and organic acids.

Nutritionists have calculated that with thermolipolysis, or the breakdown of fats (1 g), the body receives 9.3 cal, with the catabolism of carbohydrates and proteins - 4.1 cal each. When calculating the energy value of food, whole numbers are usually used, rounding them up:

Proteins	17 kJ	4 cal
Fats	37 kJ	9 cal
Carbohydrates	17 kJ	4 cal
Fiber (plant fibers)	8 kJ	2 cal
Organic acids	13 kJ	3 cal
Ethyl alcohol	29 kJ	7 cal
Polyols (polyols)	10 kJ	2, 5 cal

The amount of BJU, as well as other ingredients contained in 100 g of the product, can be found on the store label or taken from the table indicating its composition and calorie content. Multiplying these figures by the amount of energy obtained from 1 g of the food component, we find the energy value of each nutrient in 100 g of the product. But at the same time, it should be borne in mind that the human body is not able to absorb food by 100%. He digests:

• 84, 5% protein;
• 94% fat
• 95, 6% carbs.

So thatto find out the exact amount of energy that can be extracted from a particular product, you need to use the amount of nutrients absorbed by the body.

Tables of calorie content and chemical composition of products - one of the main assistants in losing weight

To keep yourself in great shape, it is very important to calculate the energy value of the foods consumed every day, as well as control the amount of calories received and expended. In the future, it is worth a lot of work to force the body to use up excess energy. Without getting a boost of energy from food, the human body in a panic begins to slow down the metabolism. This allows you to save body fat as a saving reserve from possible hunger in the future, but thereby prevents weight loss. Using ready-made data on BJU (proteins, fats and carbohydrates) from the tables, by multiplying them by the energy value of 1 g of the nutrient, we get the calorie content of each of them in 100 grams of the product. For example, kefir with a fat content of 2.5% contains per 100 ml of the product, respectively:

• 2.5 g fat (2.5 g x 9 units)=22.5 cal;
• 3g protein (3g x 4u)=12 cal;
• 4 g carbs (4 g x 4 units)=16 cal.

Summing up the results, we get the energy value of 100 g of kefir, which is 50.5 units or approximately 51 kcal, as indicated on the label.

Calorie content of the finished dish

If calculating the energy value of foods is a fairly simple process, then identifying the calorie content of cooked dishes is painstaking work.

It is necessary to weigh all the ingredients of a particular dish on a kitchen scale, taking into account not only the main components, but also additional ones. Foods such as butter (butter or vegetable), sour cream, mayonnaise especially increase the energy value of food.

Replacing sour cream, ketchup or the same mayonnaise (including "lean" or "light" types) with natural yogurt or kefir with a fat content of 1-2.5% in a salad significantly reduces the amount of calories consumed. Knowing the weight, chemical composition and energy value of breakfast foods, you can calculate its total calorie content:

• Bun toast (50 g)=149 kcal.
• Turkey 20 g=19 kcal.
• Cheese 20 g=80 kcal.
• Tomato (Medium)=25 kcal.
• A cup of coffee (130 ml)=0 kcal, adding milk 2.5% (10 ml), plus 5 kcal, and adding sugar 5 g (1 tsp), we increase the calorie content of food by another 20 kcal.

The calculated values of the energy value of individual food components are added up and we get the total number of calories consumed in the morning: 149 units + 19 units + 80 units + 25 units + 25 units=298 kcal. If you want to spread butter (5 g) on toast, you will have to increase the result by 75 cal. In this case, breakfast can give the body 373 cal.

To determine the energy value of the finished dish, taking into account additional ingredients and losses during heat treatment, you will need: a list of products according to the recipe and the weight of all ingredients ingrams. For example, 100 g of raw chicken contains proteins - 18 g, fat - 18.5 g, carbohydrates - 0.8 g. 150 grams of chicken contain: 27 g of protein, 28 g of fat and 1 g of carbohydrates. Theoretically, the energy value of 150 g of chicken is 364 kcal, of which:

• Proteins 27 g x 4 kcal=108 kcal.
• Fat 28 g x 9 kcal=252 kcal.
• Carbs 1 g x 4 kcal=4 kcal.

When boiled in water, the calorie content of which is 0 kcal, the energy value of this product will not change. After the dietary piece of boiled chicken is eaten and digested, taking into account the digestibility of various nutrients, its calorie content will be 329 kcal:

• Proteins 108 cal x 84.5%=91 cal.
• Fats 252 cal x 94%=237 cal.
• Carbohydrates 1 cal x 95.6%=0.96 cal.

Why are mono-diets bad?

When choosing a diet, it is necessary to monitor not only its calorie content, but also to ensure that it contains all categories of substances necessary for life support: BJU, vitamins, minerals.

The chemical composition and energy value of foods are important factors that have a significant impact on the quality of human life. Eating a depleted diet, which is based on a single product, you can get a short-term stunning result of losing weight, but at the same time significantly undermine your he alth.

The body with this diet works for wear and tear. According to he althy lifestyle adherents, counting calories is easy. Beginners in two weeks by eyedetermine the calorie content of familiar dishes, paying attention only to foods that are consumed for the first time. At the same time, this method well helps to lose weight without harm to he alth and consolidate the achieved result for a long time.