FAO provides information on 27 indicators of food security on the SDG-2030 (FAO, 2019a); according to other criteria of the Agenda for the period until 2030, the system of indicators is under development. Therefore, an assessment of the state of food security at the global level and FAO and scientists make due to the indicators proposed by FAO in theprocessntation of the new Sustainable Development Goals (SDGs-2).

FAO is the custodian UN agency for 21 SDG indicators and is a contributing agency for a further 4. In this capacity, FAO is supporting countries’ efforts in monitoring the 2030 Agenda (FAO, 2019b).

Proposals of national scientists regarding the methodology for assessing food security at the global level are practically absent. Some of them are borrowed from individual indicators developed by FAO for use in the national system for monitoring food security.

At the state level, the assessment of food security is carried out following the Methodology for determining the main indicators of food security, approved by the Cabinet of Ministers of Ukraine Resolution “Some issues of food security” No. 1379 dated December 5, 2007 (Cabinet of Ministers of Ukraine, 2007) (Table 1).

Proposals of national scientists regarding the improvement of this Methodology for defining the main indicators of food security are different. However, some of them require a radical change of methodology for calculating the indicator, and chage the value of the margin, and deeper analysis (calculation of additional indicators) in interpreting the results. So, Nud (2013) “believes that the 60% threshold for the indicator of economic availability of products is too high”.

Another normative document, which defines food security indicators, cannot be overlooked – The Law of Ukraine “On Food Security of Ukraine” (Verkhovna Rada of Ukraine, 2007a). Currently, this document has the status of a project, and therefore official food security reports are based on the indicators contained in the Methodology for defining key indicators for food security.

We partially agree with several comments on food security indicators in the Conclusion on the draft Law of Ukraine “On Food Security of Ukraine” (Verkhovna Rada of Ukraine, 2007b).

Such an indicator of food security, determined in clause 3 of Part 1 in article 7, as “provision of grain stockse food resources, defined as the ratio between the volumes of food grains in such resources and the volume of national consumption of bread and grain products in the calculation of grain”. It is expedient, in our opinion, to supplement it with additional Corrective indicator – “grain production per person per year, tons”. Such indicator is provided by the Methodical recommendations for calculating the level of economic security of Ukraine (Ministry of Economic Development and Trade of Ukraine, 2013). Secondly, it reduces the impact on the calculation of the marginal indicator of the adequacy of grain supplies in public food resources of such factors as the level of solvent demand (Verkhovna Rada of Ukraine, 2007a).

Grishova and Kryukova (2014) defined seven indicators and their corresponding normative values as the main indicators of food security. The authors also suggested a generalization of the system of indicators of the level of food security of the country using the integral coefficient.

The authors ranked the most significant integral indicators taking part in the formation of the integral index of food security level: the volume of grain production per capita, which forms the potential fund of population consumption; the level of economic availability of food; the share of food imports in the structure of consumption of the domestic market; the average wage as one of the main sources of household income.

In our opinion, this approach is appropriate in determining changes in the long-term dynamics or ranking of regions of Ukraine. The list of indicators is too large, and the method of their calculations is complicated.

It is possible to avoid these errors, in our opinion, if when developing a system of food security assessment indicators, take into account the criteria for the functioning of the system.

Banakh (2016) defines five basic food security criteria and their respective indicators for statistical analysis: physical accessibility; economic availability; social accessibility; food independence; ecological factor. Stezhko (2014) forms a system of indicators of the state of food security, based on three criteria (although the author calls them the direction of evaluation, and as criteria defines different indicators): physical availability of food; economic availability of food; food for consumption.

It should be noted that both Banakh (2016) and Stezhko (2014) proposed to add the indicators to the system. These are soil fertility indices (environmental factor, Banakh (2016)) and overweight population (food security for consumption, Stezhko (2014)). The first indicator is one that characterizes the degree of sustainability of agricultural development – a criterion that domestic scientists practically do not take into account. At the same time, sustainable development of agriculture is an integral part of SDG2, along with food security. The second indicator is also ignored by academics since it is believed that food security is the lack of calories, and not over their daily norm, which also leads to overweight. At the same time, in other equal terms, such an indicator simply indicates the lack of economic access to food and the replacement of quality products with cheap ones, which in turn contain so-called “empty” calories, which do not allow to satisfy the need for the necessary minerals and vitamins but overload the body with carbohydrates, starch, and others.

Another important aspect for scientists is the question of the possibilities and limits of the use of food security assessment methodology in other countries. Of course, some indicators or methodologies, or methodological approaches can be borrowed, but their use in the national system for assessing food security should be justified and appropriate. Otherwise, in the end, we will have a large block of indicators, which will be difficult to interpret. There is another problem related to the methodology of collecting and processing statistical information, which has differences in each country. On January 10, 2003, Ukraine officially became the 52^nd country (the first among the countries of the Commonwealth of Independent States), which joined the International Monetary Fund's Special Data Dissemination Standard. However, the list containing the IMF Special Data Dissemination Standard includes a limited list of indicators, most of which do not even indirectly reflect the state of food security. Volchenko (2013) introduced such indicator systems in the Russian Federation and Belarus as examples of foreign experience in the formation of the country's food security system. At the same time, we should pay attention to the fact that the data of the systems of indicators of food security assessment of the countries are based on the criteria laid down in the approved Doctrine (RF) and the Concept (Belarus), which are aimed at achieving the goals that do not coincide with the goals that Ukraine sets itself.

We can accept may the experience of foreign researchers who propose establishing an optimal level of indicators for food security. So, Bekenov (2003)Error! Reference source not found., Ilyna and Kondratenko (2007) determine the levels of optimality of food security indicators, but in the first and second cases it is only one indicator.

Russian explorer Ogluzdin (2010) proposes applying a five-point system of assessments of the state of food security. At the same time, it should be noted that it is not clear how to determine some of the proposed scientific indicators, because they sound, rather, as criteria-tasks than specific indicators. Secondly, not all indicators have limit levels defined, and therefore assign them to one of the five groups is not so easy. Thirdly, the list of indicators is too large and involves, in practice, the calculation of most of the indicators of economic, and not just food security. Instead, there are no specific indicators that determine the level of food security in the system.

We support the opinion of scientists who believe that the methodology for assessing food security indicators involves identifying their optimal, threshold and marginal levels, where the optimal level of food security indicators represents the range of values within which the most favorable conditions for reproductive processes in the national agro-industrial production are created; the threshold level is determined by the value of quantitative values, the violation of which causes unfavorable tendencies; marginal level – the limit violation of which causes threatening processes and trends in the system.

Research shows that the overwhelming majority of scientists define only the threshold levels of indicators. Some researchers' suggestions relate only to individual indicators. Thus, according to the classification proposed by Kochetkov and Markov (2002), there are seven levels of food security of the population in Ukraine, which is determined by the indicator of the daily energy value of a human diet.

Kundeeva (2013) recommends to determine “the indicator of the overall physical availability of food”, according to the criterion for assessing the level of food security, to assess the state of food security (levels of food security), and also, it is based on the actual state of the country's economy (unbalanced agricultural development and significant property stratification of the population) and the availability of statistical data.

The idea of evaluating food security on one indicator is attractive, but it is suitable for determining changes in the long-term dynamics or ranking of regions of Ukraine, that is, as part of a more complete monitoring of the state of food security.

Artimonova (2016) Error! Reference source not found.argues that “the goal and direction of food security are different for each level, but there are several characteristics of food security that are acceptable for assessing food security at all levels: ensuring food security; food security is ensured; unsafe food security; food disaster”.

In our opinion, some of these characteristics are controversial regarding the levels of food security of the household and the individual. In particular, for the consumer, the country of production is not important if the price and quality of the product meet the requirements of the individual. The same applies to the characteristic features identified by the author as “secure food security” for a particular person, the level of consumption above the minimum necessary for physiological activity cannot be a determining indicator, since an important indicator is not the number of calories, but their quality. If consumer demand for food is met mainly through own production, this means certain restrictions for a particular person concerning her personal preferences. Every country has certain restrictions in the range of production of food products, as well as the formed food stocks, which take into account a specific list of basic products, but they do not provide the personal needs of each individual.

At the same time, we agree with the author's statement that “only the integral functioning of all levels of food security – the food security at the individual, national and international levels – will allow achieving positive qualitative changes in the provision of food products to people from all over the world, region, city and the individual person.” (Artimonova, 2016).

Most scientists propose to assess food security at the regional level in the same manner as at the state level (Error! Reference source not found. According to the results that we substantiated, the necessity of taking into account the stability criterion of the food system of the region is determined, which requires a deeper investigation of this issue.

Piskunova and Osipova (2015) believe that “the indicator of the level and structure of per capita consumption of food can be the most informative and general indicator of the state of food security of the region.”

Another group of authors (Error! Reference source not found.) propose to define an “integral indicator of food security in the regions of Ukraine”: this indicator is based on the original approach, because there are less differentiation and closer interactions between the studied objects. For example, the grain stock is not taken into account, because at the regional level, the urgent transportation of grain in extreme situations is much less costly, both material and time. Consequently, only the stock of national reserves is of key importance.

The issue of food security at the household level became relevant when it was found that adequacy at the aggregated level could not ensure adequate nutrition at households or individual level. That is why the United Nations Special Committee proposed the definition of food security through the availability of food for households. Food security is provided when households have access to safe food in the amount necessary to ensure a healthy lifestyle for all its members (adequate in terms of quality, quantity, and cultural traditions) and when there is no excess risk of loss of such access (Error! Reference source not found.). Error! Reference source not found.

To establish the degree of satisfaction of personal needs through surveys, but the results will be reliable only for a certain period. On the other hand, it is fair to assert that, in other equal conditions, in the modern world, the level of income determines the level of access of a person to any material goods, including food.

Golikova (2014) believes that “food security at the household level is linked to the income of individuals.” Error! Reference source not found.The low-income level of the population leads to the fact that price fluctuations directly affect the food situation of the poorest layers not only in the city but also in the countryside. In several countries, owners of small plots of land are frequent buyers of food, they do not provide themselves with products at the expense of their plots.

However, judging from the list of goods and services that are included in the calculations in determining the subsistence minimum, in many countries, under this term, they understood no longer the minimum need. As Sokol (2012) noticed, “this is no longer the subsistence minimum in its original treatment as the poverty line, but the income reflecting the minimum rates of consumption of the employee in a given period, taking into account the state of the economy.” Error! Reference source not found.

Indicators of economic accessibility and differentiation of the cost of food by social groups become more important at the levels of the household and the individual. However, the analysis and interpretation of these indicators should be made more thoroughly according to the proposed Methodology for defining key indicators for food security. In Japan, a poor household is considered to be a family whose share of food expenditure exceeds 35% (Nud, 2013). Error! Reference source not found.By comparing the data with such threshold values, the researcher will always have false data about the actual state of affairs. Analysis of the indicator of the differentiation of the cost of food by social groups following the Methodology for defining the main indicators of food security in the “general mass” will not allow to establish dependencies and identify the problematic aspects of household nutrition. Such an approach does not take into account the culture of food and the needs of the family, depending on their place of residence.

In our opinion, from a methodological point of view, the construction of a system of food security indicators should take place through the definition of the criteria for the functioning of the system. Such an approach ensures the interconnection and interdependence between the nature, objectives, and monitoring of food security at any level.

In general, the system of indicators, approved by the Methodology for determining the main indicators of food security, meets the dimensions and criteria for food security.

At the same time, the defined system does not fully assess the criterion of implementation of effective agricultural trade policy of the state, which is the determining determinant of the national level. To ensure the objectivity of monitoring and interpretation of the obtained results, it is expedient:

Taking into account the above mentioned, there is a need for monitoring and assessment of food security at the regional level by carrying out calculations of the regional rating (ranking) of each indicator and calculating the overall rating in general for all indicatfollowingwith the Methodology for monitoring and evaluating the effectiveness of the implementation of the state regional policy (Error! Reference source not found.).

The ranking is conducted by comparing the deviation of the values of the indicators for each specific region from their best values by region for the corresponding (reporting) period and the corresponding ranking of regions from 1st to 24^th place. The rating assessment is based on the calculation of relative deviations of the indicators of each region from the maximum and minimum values of such indicators of other regions by the formula:

(1) R j = ∑ i − 1 n x m a x i − x i j x m a x i − x m i n i + ∑ i − 1 n x i j − x m i n i x m a x i − x m i n i ,

Where: R_j – amount of the rating estimates for a particular region for each of the indicators that characterize a particular year; x_ij – a value of the i-th indicator in the j-th region; x_maxi – maximum value of the ith indicator; x_mini – minimum value of the i-th indicator.

The second part of the formula is used to evaluate the indicators, which increase positively (for example, the volume of realized industrial output per capita), the first part – to assess the indicators, which increase the negative value (for example, the amount of unpaid wages).

Determination of the average arithmetic value of the sum of rating assessments of a specific region for all indicators of the annual evaluation, which characterize a separate line of activity, is carried out by the formula:

(2) R c p   j = R j n ,

Where: R_cpj – an average arithmetic sum of ratings of a specific region for all indicators of a particular year; n – the number of indicators used for the calculation for a particular direction.

Due to the results of calculations, the integral rating is determined as the average arithmetic mean of the sum of rating estimates of a particular region for all years by the formula:

(3) I j = ∑ 1 m R c p   j , m

Where: I_j – an average arithmetic sum of ratings of a specific region for all years; m – number of years for which the calculation was made.

The criterion of stability of the food system of the region is characterized by indices of production and consumption of the main types of foodstuffs, branching out of the retail chain, as well as a system for reducing, processing and subsequent use of food waste.

Official statistics do not provide information according to the latest criterion, to perform calculations of the ranking of regions with levels of food security, we propose the use of the 9 indicators (Figure 3).

In general, the scheme for researching at the regional level will include six stages (Figure 4).

In our opinion, it is advisable to apply the approaches proposed by Golikova K.P. (Error! Reference source not found.) Error! Reference source not found.to assess the food security at the household level, and Mostenska T.G. (Error! Reference source not found.). Error! Reference source not found.

The first approach ensures the objectivity of the analysis of the economic availability of products by comparing: the actual consumption of food with a consumer basket and rational standards; ratio and share of food costs in total costs and subsistence minimum. The second approach allows us to establish dependencies and identify the nutritional aspects of households depending on their place of residence.

In respect that neither the first nor the second approaches make it possible to characterize the health of household members as the main criterion for food security at the household level, therefore, in our opinion, to carry out a comprehensive assessment of food security at the household level, it is expedient to analyze the indicators of the expected life expectancy at birth (years) and the rate of infant mortality (deaths of children under one year per 1,000 live births). Even more problems, regarding the assessment of food security at the level of the individual, occur as follows: on the one hand, the main criterion for achieving it is the degree of satisfaction of personal needs; and on the other hand, it is necessary to comply with the principle of state administration of personal interests' subordination to the national ones, after all, eventually, only such an approach can ensure the rights and freedoms of everyone.

The hypothesis of the study is the assumption that there is a significant overproportion in the level of consumption of food products by different categories of households as well as an impact of the economic availability of products upon this misbalance. Based on this thesis, it is proposed to evaluate the level of food security of households in terms of by households' categories, based on the main indicators of food economic availability and consumption (Figure 5).

There are discussions around the issue of food security indicators. In general, the proposals of domestic scientists regarding the improvement of the food security assessment system are based on the official Methodology for defining the main indicators of food security (Error! Reference source not found.) and are mainly concentrated in five areas:

The world's scientific community also does not offer the unified indicators' system for food security monitoring at various levels, only for global one, whose indicators' system was developed by FAO (2019a).

The proposed system solves a range of problems that currently exist: firstly, in the domestic monitoring system, there are developed indicators only at the national level; however, we proposed system that covers all levels; and secondly, the criteria underlying the national food security monitoring system do not meet the SDGs; instead, our proposed system of indicators is based on the need to achieve the SDGs2.

The developed system of indicators and margins of food security ensures monitoring and evaluation of the achievement of the criteria of the respective levels (global, national, regional, households, and individuals) based on the actual official information provision of the processes of food security according to the SDGs2.

The proposed system of indicators allows monitoring of food security in a systematical and integrated way, at various hierarchical levels, which enables the quality management of food security taking into account specific features and needs at each level (Figure 6).

Further research will be aimed at making the strategic framework and mechanism for ensuring food security at various hierarchical levels, taking into account the monitoring results of the proposed methodology.