Energy Costs, Energy Balance
Energy costs consist of human-regulated energy expenditure and unregulated energy costs. The unregulated types of energy costs include energy expenditure for a specific dynamic action( SDA) and basic exchange. The basal metabolism level for a person with a body weight of 70 kg averages 4.1868 kJ per kg per hour, or 7117.56 kJ / day( 1 kcal is 4.1868 kJ).The size of the basal metabolism depends on the age and sex of the person. The main exchange in a person decreases with age. In men, the basal metabolic rate is 5-10% higher than in women.
Thanks to the intake of food, which causes an increase in oxidative processes in the body, the energy expenditure of a person is increased. The main metabolism increases with a mixed diet of 10-15% per day. The greatest increase in metabolism( by 30-40%) is caused by the intake of proteins, with the intake of fats, the metabolism increases by 4-14%, and when carbohydrates are taken 4-7%.
Regulated energy costs are determined by its consumption in the performance of muscular work.
The energy consumption of a person for the work done during the day depends on the nature of the production activity, the amount of homework, the mode of work and rest, as well as the peculiarities of using the time off from work. Physical stress is accompanied by a greater increase in energy expenditure compared to mental work. Numerous studies were carried out involving large contingents of subjects, as a result, the average values of energy expenditure were determined for various types of physical and mental activity. Based on the conducted studies, special tables of energy consumption were compiled for various types of human activity.
To calculate the energy expenditure, you first need to carry out the timekeeping of the daily activity of a person with a clear fixed time, which is expended on one or another type of work. And then the energy expenditure table is used for various activities.
To determine the requirement for basic nutrients and energy, the accuracy of the recommended level of energy consumption is necessary, and the possibility of disparities between levels of energy intake and food consumption is necessarily eliminated. The possibility of such a disproportion is associated with a systematic reduction in the energy intensity of labor activity and energy consumption in everyday life, which outstrip changes in the existing image of nutrition and are the cause of the widespread redundancy of body weight. The energy needs calculation data should show the quantities that are needed to maintain the desired body weight and to ensure an optimal level of social and physical activity, and therefore a healthy lifestyle.
In the modern literature hygienic standards of daily energy costs for people with different professions are presented.
I group - workers of intellectual work .These include: enterprise managers, teachers, scientists, physicians( other than surgeons), writers, journalists, print workers, students. The daily energy consumption is 2550-2800 kcal for men, 2200-2400 kcal for women, ie an average of 40 kcal / kg of body weight.
II group - workers of light physical labor .These include: workers of automated lines, sewing machines, veterinarians, agronomists, nurses, sellers of manufactured goods, instructors in physical culture, coaches. The daily energy consumption is 3000-3200 kcal for men and 2550-2700 kcal for women, i.e.an average of 43 kcal / kg of body weight.
III group - workers of average severity .These include: surgeons, drivers, food industry workers, water transport workers, food vendors. Daily energy consumption is 3200-3650 kcal for men and 2600-2800 calories for women, an average of 1 kg of weight 46 kcal / kg of body weight.
IV group - workers of heavy physical labor .They include: builders, metallurgists, machine operators, agricultural workers, athletes. The daily energy consumption is 3700-4250 kcal for men and 3150-2900 kcal for a woman, an average of 53 kcal / kg of mass.
V group - the person of especially heavy physical labor .These include: steelworkers, miners, loggers, loaders. The daily energy consumption is 3900-4300 kcal for men, an average of 61 kcal / kg. For women, this expenditure is not standardized.
The above energy costs are calculated for men( 70 kg) and women( 60 kg) of medium weight. In each of the above groups, three age categories must be observed: 18-29 years, 30-39 years and 40-59 years. For people aged 60-74, the average daily energy consumption for men is 2300 kcal, for women - 2100 kcal. For people over 75 years, the average daily energy consumption for men is 2000 kcal and for women - 1900 kcal. For working people of the retirement age, energy consumption is increased by 5-10%.The recommended average daily energy consumption should be adjusted, adjusted for the area of residence:
north - plus 10-15%;
south - minus 5%.
In addition, to determine the energy expenditure, according to the recommendations of the World Health Organization, an objective physiological criterion is introduced and used, which determines the adequate amount of energy for specific groups. Such a criterion was the ratio of total energy expenditure to all types of vital activity with the value of the basic exchange, i.e.energy consumption at rest. Energy consumption at rest depends on sex, body weight and age. The value of the coefficient of physical activity is determined by the ratio of total energy expenditure to the value of the basal metabolism. For example: if the energy expenditure on all types of vital activity is twice the amount of the basic exchange for the corresponding group by age and sex, this means that for a given group the coefficient of physical activity is two.
Materials used:
Shilov VN, Mits'yo VP"Healthy Nutrition"