Hatice Merve
Bayram
and
Arda
Ozturkcan
*
Istanbul Gelisim University, Faculty of Health Sciences, Department of Nutrition and Dietetics, Istanbul, Turkey. E-mail: turkcana@hotmail.com
First published on 8th December 2022
Due to the expected growth rate in world energy consumption in the near future, it is critical to estimate future energy consumption and associated environmental problems as precisely as possible. This study aims to describe total greenhouse gas emissions (GHGE) linked to different geographical diet profiles in Turkey, to map the environmental impacts that these generate. We used the last Address Based Population Registration System results to identify regions, populations, and some developmental parameters such as population density, the population growth rate, gross domestic product per capita, and socio-economic development scores, and the latest National Nutrition and Health Survey to determine the nutrient composition of Turkey's regional diets. The West Marmara diet had the highest GHGE levels, at 2983.79 g CO2-eq. per person per day, followed by the Istanbul diet and South-eastern Anatolia diet (2941.73 g CO2-eq. per person per day and 2935.08 g CO2-eq. per person per day) whereas the Mediterranean diet had the lowest, at 2623.90 g CO2-eq. per person per day. The contributions of beef and lamb to total diet weight (both were 0.98%) were lower than their contribution to total GHGE (21.65% and 21.04%). Our findings indicated that dietary changes could significantly help to reduce GHGE. Additionally, GHGE of diets might be associated with developmental parameters, but we did not find statistical differences. If the balance between natural resources and economic growth factors cannot be achieved in developing countries such as Turkey, which is a member of the United Nations, the environment will start to suffer and environmental sustainability will become a distant goal. Therefore, more studies are needed to confirm these results.
The world is under the threat of global warming, and greenhouse gas emissions (GHGE) have affected both the natural environment and humans. According to the last Intergovernmental Panel on Climate Change (IPCC) report (2013), the primary cause of global warming is human activities, 95% of which occurred since the middle of the twentieth century.4
Food systems play a key role in driving climate change including all processes in the production, aggregation, processing, distribution, consumption, and disposal of food products. Therefore, reduction of GHGE of food systems is required.5–7 Among all these processes involved in food systems, food consumption is one of the most important as a climate change mitigation option. It is recommended that consumption of more plant-based, organic and regional-based diets is important for reducing GHGE.8–10 In this line, IPCC estimates that dietary changes might decrease the total GHGE by 0.7–8 GtCO2-eq. per year by 2050.7
The developmental processes for a country mainly depend on economic growth. Natural resources serve as inputs into the production or development process. If the relationship between natural resources and development processes cannot be avoided, damage to the environment is inevitable.11 The prevalence of such problems is higher in developing countries such as Turkey, where economic growth and environmental sustainability are critically important. Also, the share of the Turkish industrial sector in gross domestic product was approximately 26% and thereby a key driver of the economic growth as in many other countries.12 Some studies have focused on the relationship between economic growth and GHGE with their possible influencing factors such as population and energy consumption,11,13–19 but there is no study about this subject in Turkey according to the last Turkish Greenhouse Gas Inventory Report (2021).20
Due to the expected growth rate in world energy consumption in the near future, it is critical to estimate future energy consumption and associated environmental problems as precisely as possible. Thus, the energy consumption structure can be correctly presented, the relationship between energy consumption and economic developmental parameters can be coordinated, and countermeasures can be determined against energy-related environmental problems (e.g. CO2 emissions).2 According to the last Turkish Greenhouse Gas Inventory Report (2021), total GHGE in 2019 decreased by 1.4% compared to 2018 emissions in Turkey, however, the total GHGE per individual is 6.4 tons of CO2 equivalents (CO2 eq.).20 Given the dramatic changes and the region's growing influences globally on many levels, each region has different diets and economic growth factors. This study aims to describe total GHGE linked to different geographical diet profiles in Turkey, to map the environmental impacts that these generate. Additionally, the relationship between GHGE linked to geographical diets and developmental parameters such as population, population growth rate, gross domestic product per capita, and socio-economic development scores of a country was analyzed. The first hypothesis was GHGE linked to geographical diet profiles is different. The second hypothesis was there is a relationship between GHGE linked to different regions' diets and developmental parameters.
ABPRS is a modern database where the information about the population of people according to their place of residence is kept up-to-date and population movements can be monitored at any time.23 In this study, we included all the regions from Turkey which are divided according to the nomenclature of territorial units for statistics (NUTS) due to these regions' use by the National Nutrition and Health Survey (NNHS).24 NUTS is a geocoding system that originated in the 1970s in Europe. The main purpose of these regional units is to collect statistics on a regional basis, conduct socio-economic analyses, and create the framework of regional policies for society.25
According to the NUTS classification, we calculated the total population size, population density, population growth rate, gross domestic product per capita, and socio-economic development scores for each region (Table 1).
NUTS regions | Number of urban extents | Population size | Population density | Population growth rate | Gross domestic product per capita | Socio-economic development scores |
---|---|---|---|---|---|---|
Istanbul | 1 | 15![]() ![]() |
2831 | 15![]() ![]() |
86![]() |
4.051 |
West Marmara | 5 | 3![]() ![]() |
84 | 3![]() ![]() |
109![]() |
3.129 |
Ege | 8 | 10![]() ![]() |
120 | 10![]() ![]() |
151![]() |
5.538 |
East Marmara | 8 | 8![]() ![]() |
169 | 7![]() ![]() |
123![]() |
7.454 |
West Anatolia | 3 | 8![]() ![]() |
109 | 7![]() ![]() |
112![]() |
3.563 |
Mediterranean | 8 | 10![]() ![]() |
120 | 10![]() ![]() |
128![]() |
2.417 |
Middle Anatolia | 8 | 4![]() ![]() |
45 | 3![]() ![]() |
75![]() |
−0.721 |
West Black Sea | 10 | 4![]() ![]() |
63 | 4![]() ![]() |
105![]() |
−0.561 |
East Black Sea | 6 | 2![]() ![]() |
105 | 2![]() ![]() |
35![]() |
−1.104 |
Northeast Anatolia | 7 | 2![]() ![]() |
31 | 2![]() ![]() |
57![]() |
−6.349 |
Middle-east Anatolia | 8 | 3![]() ![]() |
48 | 3![]() ![]() |
53![]() |
−7.923 |
South-eastern Anatolia | 9 | 9![]() ![]() |
120 | 8![]() ![]() |
80![]() |
−9.583 |
In the NNHS, trained dietitians collected food consumption data from individuals using 24 hour dietary recall and food frequency questionnaire methods.24 Both methods were carried out in two independent times separated by two weeks (10–14 days), as recommended by the European Food Safety Authority and dietary intake was expressed in grams consumed per person per day.26
Additionally, the meat consumption is given only as the total amount of meat and meat products such as red meat, poultry, and fish and their products in the NNHS. It is well known that the GHGE values of varieties of meat and meat products are extremely different from each other (ESI Table 1†). Therefore, to calculate the mean contributions to GHGE, total meat and meat product consumption were divided into four categories by 1/2 red types of meat like beef, lamb and 1/4 poultry, and 1/4 fish. The reason for this separation was that Turkey's overall food consumption is given by red meat, poultry, fish, and their products, but the food consumption of NUTS regions is given only by the main food groups. According to the data, consumption of red meats and products was higher than the others. Thus, we divided the total meat consumption: 1/2 red types of meat, 1/4 poultry, and fish.
The data from the NNHS has uncertainties in the composition of the diets. As shown in ESI Table 1,† the variables with uncertainties in this study are GHGE values.
A flowchart about the study is presented in Fig. 1.
Food type | Istanbul (n: 1811) | West Marmara (n: 673) | Ege (n: 2204) | East Marmara (n: 1315) | West Anatolia (n: 1143) | Mediterranean (n: 1734) | Middle Anatolia (n: 667) | West Black Sea (n: 828) | East Black Sea (n: 389) | Northeast Anatolia (n: 256) | Middle East Anatolia (n: 542) | South-eastern Anatolia (n: 891) | All regions (n: 12![]() |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|
a The values were calculated according to the total food consumption over the age of 15 and the GHGE values are expressed in g CO2-eq. per person per day. | |||||||||||||
Dairy products | 266.32 | 273.14 | 252.01 | 250.06 | 249.23 | 273.41 | 224.76 | 229.35 | 236.86 | 254.23 | 265.35 | 315.81 | 257.54 |
Beef | 679.62 | 672.15 | 623.65 | 600.69 | 611.31 | 497.37 | 619.35 | 603.56 | 688.80 | 609.88 | 605.57 | 654.36 | 622.22 |
Lamb | 660.67 | 653.42 | 606.27 | 583.95 | 594.27 | 483.51 | 602.08 | 586.74 | 669.60 | 592.88 | 588.69 | 636.12 | 604.87 |
Fish and seafoods | 104.43 | 103.28 | 95.83 | 92.30 | 93.93 | 76.43 | 95.17 | 92.74 | 105.84 | 93.71 | 93.05 | 100.55 | 95.61 |
Poultry | 97.56 | 96.49 | 89.53 | 86.23 | 87.76 | 71.40 | 88.91 | 86.64 | 98.88 | 87.55 | 86.93 | 93.94 | 89.32 |
Eggs | 119.33 | 114.58 | 102.38 | 123.74 | 108.82 | 104.75 | 106.79 | 97.97 | 102.38 | 111.19 | 87.80 | 86.78 | 105.53 |
Legumes | 16.56 | 20.61 | 14.22 | 16.83 | 14.49 | 13.14 | 15.93 | 17.37 | 14.04 | 13.95 | 13.05 | 12.51 | 15.23 |
Nuts | 61.36 | 50.96 | 44.72 | 52.00 | 50.44 | 52.00 | 57.72 | 58.76 | 73.32 | 42.12 | 36.92 | 34.84 | 51.27 |
Vegetables | 120.41 | 114.16 | 130.52 | 100.44 | 120.27 | 129.96 | 119.57 | 132.21 | 115.76 | 100.77 | 107.63 | 120.09 | 117.65 |
Fruits | 63.65 | 77.05 | 83.80 | 69.85 | 91.25 | 94.85 | 102.90 | 83.40 | 86.05 | 61.70 | 80.20 | 71.65 | 80.53 |
Bread, cereals and bakery products | 349.55 | 373.43 | 362.66 | 350.66 | 367.91 | 384.74 | 397.58 | 364.87 | 342.65 | 474.44 | 425.87 | 428.63 | 385.25 |
Oils and fats | 73.70 | 82.08 | 78.24 | 76.11 | 68.87 | 73.41 | 62.05 | 70.29 | 70.29 | 64.18 | 60.21 | 58.22 | 69.81 |
Sugar and sweeteners | 2.94 | 3.00 | 3.03 | 3.19 | 2.94 | 3.07 | 3.04 | 2.99 | 3.16 | 4.41 | 3.58 | 2.79 | 3.18 |
Soft drinks | 325.62 | 349.44 | 377.74 | 359.58 | 386.30 | 365.86 | 297.34 | 323.62 | 271.46 | 376.58 | 304.06 | 318.80 | 220.28 |
Total | 2941.73 | 2983.79 | 2864.59 | 2765.63 | 2847.79 | 2623.90 | 2793.18 | 2750.52 | 2879.09 | 2887.59 | 2758.91 | 2935.08 | 2718.29 |
![]() |
|||||||||||||
Energy and macronutrients | |||||||||||||
Grams per day | |||||||||||||
kcal per day | 1854.17 | 1968.75 | 1881.00 | 1841.03 | 1832.99 | 1877.28 | 1864.38 | 1840.03 | 1829.45 | 2032.95 | 1883.60 | 1875.29 | 1881.74 |
g of protein per day | 54.71 | 56.61 | 52.92 | 51.99 | 52.82 | 51.18 | 54.45 | 52.64 | 52.67 | 58.47 | 55.02 | 57.74 | 54.27 |
% of kcal | 11.80 | 11.50 | 11.25 | 11.30 | 11.53 | 10.91 | 11.68 | 11.44 | 11.52 | 11.50 | 11.68 | 12.32 | 11.54 |
g of fat per day | 82.14 | 86.89 | 81.71 | 80.92 | 75.49 | 76.67 | 70.99 | 76.40 | 80.01 | 71.53 | 67.75 | 68.31 | 76.57 |
% of kcal | 39.87 | 39.72 | 39.10 | 39.56 | 37.07 | 36.76 | 34.27 | 37.37 | 39.36 | 31.67 | 32.37 | 32.79 | 36.62 |
g of carbohydrate per day | 224.02 | 240.07 | 233.49 | 226.19 | 235.57 | 245.62 | 251.91 | 235.48 | 224.67 | 288.83 | 263.45 | 257.37 | 243.89 |
% of kcal | 48.33 | 48.78 | 49.65 | 49.15 | 51.41 | 52.34 | 54.05 | 51.19 | 49.12 | 56.83 | 55.95 | 54.90 | 51.84 |
The contributions of beef and lamb to total diet weight (both were 0.98%) were lower than their contribution to total GHGE (21.65% and 21.04%). Additionally, bread, cereals, and bakery products were the third-highest food group that contributed to total GHGE with 13.4%, their contribution to total diet was 12.67% (Fig. 2).
![]() | ||
Fig. 2 The contributions of each food group in the average diet of all regions to total diet weight (% of total gram per day) and total greenhouse gas emission (% of total g CO2 eq. per day). |
The correlation analysis showed that the average GHGE levels linked to different geographical diets are not associated with population, population density, population growth rate, gross domestic product per capita, and socio-economic development scores (p > 0.05) (Table 3).
Population size | Population density | Population growth rate | Gross domestic product per capita | Socio-economic development scores | GHGE | |
---|---|---|---|---|---|---|
a p < 0.05. b p < 0.001. | ||||||
Population size | — | r: 0.831, p < 0.001b | r: 0.986, p < 0.001b | r: 0.650, p: 0.022a | r: 0.503, p: 0.095 | r: −0.140, p: 0.665 |
Population density | — | — | r: 0.803, p: 0.002a | r: 0.570, p: 0.053 | r: 0.606, p: 0.037a | r: 0.120, p: 0.711 |
Population growth rate | — | — | — | r: 0.650, p: 0.022a | r: 0.510, p: 0.090 | r: −0.084, p: 0.795 |
Gross domestic product per capita | — | — | — | — | r: 0.776, p: 0.03a | r: −0.217, p: 0.499 |
Socio-economic development scores | — | — | — | — | — | r: −0.021, p: 0.948 |
According to the linear regression analysis, no statistical differences were found between the average GHGE levels linked to different geographical diets and parameters such as population, population density, population growth rate, gross domestic product per capita, and socio-economic development scores (p > 0.05) (Table 4).
Parameters | All regions |
---|---|
Population size | 0.860 |
Population density | 0.490 |
Population growth rate | 0.846 |
Gross domestic product per capita | 0.956 |
Socio-economic development scores | 0.788 |
The global population increases day by day, and it is estimated that it will require an increase in food production over the next 30 years, particularly in developing countries.31 Countries need to increase domestic agricultural production to meet this increasing food demand and remain self-sufficient.32 Food consumption is associated with behaviour, life, and cultural norms, and has a crucial influence on energy use, and leads to a high contribution to GHGE.33 65% of global GHGE and 50–80% of the land, water, and material use can be directly and indirectly related to household food consumption.34 Additionally, it is suggested that consumption of more plant-based, organic and regional-based diets is important for reducing GHGE.8,10 Our result showed that the Mediterranean region diet has the lowest GHGE levels. The Mediterranean diet includes all vegetables and fruits, predominantly green leafy vegetables, and lower consumption of red meat, and meat products.35 Therefore, it causes less environmental impact than other nutrition models (except vegetarian diets), due to the lower contribution to the GHGE.36 Additionally, the protective effects of this diet model against many diseases, especially cardiovascular diseases, have been shown.37 Thus, it can be interpreted as a nutritional model that contributes to both health and sustainability.
Meat and meat products have a higher contribution to the diet GHGE, therefore, a strategy for reducing diet-related GHGE is to replace red meat and meat products with alternative protein sources, including vegetarian alternatives.38 In this study, the contributions of beef had the highest value to the average GHGE levels linked to geographical diets at 21.65%, followed by lamb at 21.04%. While consumption of meat and meat products was lowest in the Mediterranean region diet, it was followed by the Eastern Marmara diet. In addition, the dietary GHGE levels of Eastern Marmara were ranked 9th among all regions. Considering that the total dietary GHGE showed little change, it could be said that the reduction in meat consumption has a positive effect on the GHGE.
From 1990 to 2018, the total GHGE rapidly increased in Turkey. Although the total GHGE in 2019 decreased by 1.4% compared to 2018 emissions, there is a 161% increase compared to 1990. While the energy sector had the largest portion of total GHGE at 72%, followed by agriculture at 13.4%, industrial processes and product use stood at 11.2%, and waste at 3.4%.20 Additionally, in parallel with economic growth, the population size has increased since 1990, but this increase showed the lowest level of 0.55% from 2018 to 2019.39 But, it is not known how much the GHGE levels linked to geographical diets contribute to the total GHGE and what the relationship between the GHGE levels of diets and economic growth factors is. In the present study, there were no statistical differences between the GHGE levels of diets and population size, density, and growth rate, gross domestic product per capita, and socio-economic development scores. These results showed that regional diet-linked GHGE was not related to developmental parameters. Additionally, there were no details of the GHGE levels of any of the environmental factors from the production of food to wastage. Only one stage of a product's life was used in this study. Therefore, it may not have found a statistically significant result.
The present study had some limitations. First, GHGE data from food production was limited in Turkey. The GHGE levels from the literature reviews were used. However, food production has similar standards worldwide and the reviews seem to be confident, most of the impacts affect GHGE such as energy carriers, climate characteristics, regional soil, water use, etc. Second, this study did not use all of the life cycle steps of food products such as transportation, cooking, and wasting. Third, the NNHS had limited data about food choices in the diet of regions. Therefore, the overall levels of GHGE from the literature reviews were used, but these results may not reflect the exact diet-related GHGE.
Footnote |
† Electronic supplementary information (ESI) available. See DOI: https://doi.org/10.1039/d2fb00027j |
This journal is © The Royal Society of Chemistry 2023 |