Introduction

Considering that 41 million children worldwide are overweight and obese [1], the epidemic nature of obesity in childhood is a dramatic reality [2]. Obesity is a multifactor disease that may develop in combination of different factors like obesogenic environment [2], social, economic, behavioral, and biological factors [3]. Obesogenic environment leads to obesity through the positive energy balance that develops by decreased physical activity, increased consumption of high-energy foods, and longer times spent in front of the screen [2].

On the other hand, it is increasingly important to understand the neurobiological mechanism of obesity [4]. While homeostatic balance is not sufficient by itself to explain dietary behavior [5], food consumption is controlled by various mechanisms such as peripheral, endocrine, central factors, and reward systems [6]. As a result of the sensitivity of the reward system and disruption of energy homeostasis via neurobiological pathways that regulate the control of inhibitors in this system, the affected reward cycle may lead to compulsive food intake which is considered as addiction in some people. Excessive eating tendency that leads to various complications such as obesity had similar neurobiological characteristics of those in substance addiction [7]. It is argued that, especially salty, fatty, sugary foods, and foods with additive agents have a higher potential of addiction, rather than foods like vegetables, fruits, or lean meat [8, 9]. It is suggested that higher hedonic desire towards fatty and sugary foods may be related to increased neuropeptides and neuromodulators that contain anandamide and endocannabinoids [10]. Nevertheless, a study reported that consumption of tasty high-sugar and high-fat foods, in the same way as in substance addiction, changes the brain functions that include the mesolimbic dopamin reward function [11]. According to all these, the presence of food dependency on obese individuals may indicate that food dependency is effective in the development of obesity [12]. In a study where the relationship between childhood obesity and food dependency was investigated, it was reported that the food dependence ratio in children and adolescents in the 99th BMI percentile was 71% and 83.1% [13].

Unfortunately, starting with the early stages of their lives, children are highly exposed to packaged products with high-energy content that provide pleasure in consumption and turn into a habit of life-long consumption. Therefore, this study aimed to investigate some energy and nutrient contents of easy to reach ‘junk food’ children are encouraged to consume, and emphasize the magnitude of the danger.

Methods

The location, time, and sampling of the study

This study included packaged foods that are thought to have high-sugar, -fat, or -salt contents sold in 6 hypermarkets with high sale capacities located in Ankara between June 2016 and September 2016. All products in the snack sections of the markets were included.

The general setting of the study

The study included a total of 435 packaged foods from 24 different brands. The numbers of the types of products taken from the brands are given in Table 1.

Table 1 Number of brands and products included in the study
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The contents of energy (kcal), total fat (g), saturated fat (g), carbohydrate (g), sugar (g), and sodium (g) per 100 g of the products as captured on their labels were recorded for analysis. In addition, the number of products where these nutritional elements are provided in label information is determined, and this number is shown in the tables as ‘n’. As the sodium content was not included in labels of all products, the sodium value was calculated by multiplying the salt value on the labels by 0.4. The data were collected by the researchers by taking the photos of the products on hypermarket shelves and storing them.

Statistical analysis

The data obtained in the study were analyzed using the SPSS 15 package software. Number (N) and percentage (%) tables were formed for qualitative data. Arithmetic mean (\(\bar {x}\)), standard deviation (SD) and range values were given as descriptive statistics.

Results

Table 2 shows the mean, standard deviation, range values of the energy, and some nutrient contents of the types of biscuits, cakes, crackers, and chips included in the study. Accordingly, chips had the highest energy content by 514.0 ± 27.80 kcal and highest fat content by 27.9 ± 5.23 g. Among the group, the highest saturated fat and carbohydrate contents were found in biscuits (respectively 10.7 ± 3.84 and 67.3 ± 7.03 g). The highest sugar content was in cakes (33.4 ± 6.94 g). Chips (0.6 ± 0.16 g) and crackers (0.9 ± 0.23 g) had the highest sodium content. Although they contained sugar, no information was included on the labels regarding sugar content in 16 biscuit products, 12 cake products, and 2 cracker products (Table 2).

Table 2 Mean (\(\bar {x}\)), standard deviation (SD), and range values for energy and some nutrient contents in types of biscuits, cakes, crackers, chips, chocolates, bars, wafers, ice cream, fruit yogurt, pudding, and breakfast cereals (100 g)
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The mean, standard deviation, and range values of the energy and some nutrient contents in types of chocolates, bars, and wafers are given in Table 2. Accordingly, chocolates had the highest values for energy by 546.2 ± 22.39 kcal, for fat by 33.0 ± 4.28 g, and for sugar by 45.6 ± 5.95 g. While the highest values for saturated fat (19.2 ± 3.89 g) and Carbohydrates (58.8 ± 5.40 g) were found in wafers, the highest sodium content was found in bars (0.2 ± 0.09 g). No information was provided about sugar content in 6 chocolate types, 5 bars, and 12 wafer products (Table 2).

The mean, standard deviation, and range values of the energy and some nutrient contents in types of ice cream, fruit yogurt, pudding, and breakfast cereals are given in Table 2. According to this table, breakfast cereals had the highest contents of energy (386.0 ± 14.87 kcal), Carbohydrate (76.2 ± 3.80 g), sugar (23.8 ± 5.46 g), and sodium (0.3 ± 0.23 g). Ice creams had the highest contents of total fat (10.8 ± 6.79 g) and saturated fat (8.1 ± 4.67 g). No information was provided about sugar content in 25 ice cream types and 5 pudding products (Table 2).

Table 4 shows the distribution of the foods in the scope of the study according to the health code criteria in the Turkish Food Codex Labeling Directive published by the Ministry of Food, Agriculture and Livestock [14]. Accordingly, unhealthy amounts were found in terms of sugar in 363 (83.4%) products, in terms of fat in in 93.7% of the products, in terms of saturated fat in 92.4% of the products, and in terms of sodium on 70.3% of the products among all 435. According to the results, most products in the shelves are ‘unhealthy products’ as they do not comply with health code criteria.

Discussion

Excessive weight and obesity have recently become a significant public health issue among children and adolescents in the world. One of the reasons for increased obesity prevalence is the obesogenic environment in industrialized countries that promotes excessive consumption of foods with high energy, sugar, saturated fat, and sodium contents, while inclusion of these products in shops increased and access to these became easier [15].

According to the Turkish Food Codex Labeling Directive, based on 100 g measurements, a food is low-sugar if it contains < 5 g sugar, it is low-fat if it contains < 3 g fat, and it is low-sodium if it contains < 0.12 g sodium. In addition, to consider a food as low-saturated-fat, the energy provided by saturated and trans fatty acids must be lower than 10% of the total energy [14]. The vast majority of the foods included in the study were found to be ‘unhealthy’ as they did not comply with the health code criteria determined by the Turkish Food Codex Labeling Directive (Table 4). In a study where products targeting children and those targeting adults were compared, the salt, sugar, and fat contents of 147 yogurts, 145 grain bars, and 144 ready meals were compared, and it was found that the sugar, total fat, and saturated fat contents of yogurts and grain bars targeting children were higher than those of the same products targeting adults. It was also found that the sodium contents of ready meals and yogurts were lower [16]. In a study investigating 186 foods produced for babies and children, more than 53% of the products had higher than 20% of their energy supplied by sugar, and more than 12% of these had medium (130–260 mg) or high (> 260 mg) sodium levels [17]. These data show that children are subjected to the effects of the consumer society which lead to obesity. Therefore, it is an important necessity that children are protected from the environmental factors that lead them to obesity.

Especially, the consumption of high-sugar foods, just as in substance addiction, promotes higher consumption of these foods by affecting the reward system of the brain [18]. A study found that it is easier to reduce the amount of fat in biscuits than to reduce the amount of sugar, and it is more difficult for a consumer to notice the difference [19]. In another study with breakfast biscuits, liking of the biscuit with 33% reduced fat increased significantly in 4 weeks, while biscuits with 9% and 16% reduced sugar were liked more than the biscuit with 28% reduced sugar [20]. In a study on puddings, women were given four different puddings containing lower/higher amounts of sugar and fat, and it was observed that the women were able to distinguish low- and high-sugar puddings, while they were not able to distinguish low- and high-fat puddings clearly. Accordingly, it was concluded that sugar is more effective on the hedonic system [21].

The maximum daily intake of sugar in terms of healthy living principles was determined for the first time in 1989 by WHO as 10% of total energy, and this amount was confirmed by WHO and the Food and Agriculture Organization (FAO) again in 2002 [22]. In this study, it was found that 63.2% of the foods included more than 10% of the total energy in sugar. Sugar consumption amounts of children and adolescents in Turkey were found as 8.98 g in males and 10.42 g in females of age 2–5; 10.59 g in males and 13.21 g in females of 6–8; 11.94 g in males and 12.89 g in females of age 9–11; 16.46 g in males and 13.63 g in females of age 12–14; 19.01 g in males and 14.78 g in females of age 15–18 (Table 3) [23]. In a study with 262 children of age 7–12 that emphasized that sugar consumption had a big contribution on development of obesity recently, a positive relationship was found between BMIs of the children and their sugar consumption [24]. It was reported that sugar consumption in childhood paves the way for cardiovascular diseases by increasing adiposity and dyslipidemia [25].

Table 3 Sugar intake of males and females in 2–18 years
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As a result of the study, it was found that chocolates had the highest total fat (33/100 g) and wafers had the highest saturated fat (19.2/100 g) contents among the others (Table 2). According to the analysis of the foods in the scope of the study based on the health code criteria in the Turkish Food Codex, 408 (93.7%) of the 435 foods exceeded the recommended fat amount, 402 [92.4% exceeded the saturated fat amount (Table 4)]. In scope of healthy living principles, WHO/FAO recommended that the daily energy consumption needs should be met by 25–30% with total fats, and the energy coming from saturated fatty acids should not exceed 10% [26]. This is because high-fat dietary patterns are strongly related to high BMI-Z scores [27]. In another study, 1696 children of 6 to 9 years of age were asked to consume low- and high-fat crackers with low- and high-sugar apple juice, and children’s preference of high-fat cracker and high-sugar juice was found to be positively related to their status of weight [28]. It was an interesting finding in this study that chocolates had higher fat contents (33.0 ± 4.28/100 g) than even chips (27.9 ± 5.23/100 g) (Table 2).

Table 4 Distribution of the foods in the study based on health code criteria
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It was also found that, by their respective sodium contents of 0.9 and 0.6 g, crackers and chips had the highest amounts of sodium (Table 2). According to the analysis of the foods in the scope of the study based on the health code criteria in the Turkish Food Codex, 306 (70.3%) of the 435 foods exceeded the recommended amount of sodium (Table 4). According to a study conducted with American children and adolescents, sodium consumption was found 3260 g in the age interval of 8–12, and 3486 mg in the age interval of 13–18. It was noteworthy that these numbers were much higher than the recommended amount of 2300 mg [29]. In another study, it was found that 90% of children between the ages of 6 and 18 years consumed much more sodium than they are required to take [30].

In the Turkey Nutrition Guide 2015, it was stated that in Turkey, the 95th percentile of sodium consumption is 4023 mg, and this amount which may be considered maximal corresponds to about 10 g of salt intake with food per day. It was reported that the excessive sodium intake rate tolerable by foods in children and adolescents is 22.2% [31]. In a study, it was found that the sodium in the 24-h urine of overweight and obese individuals is higher, an excessive amount of salt by 1 g/day increased the risk of obesity in children by 28%, and excessive salt consumption is significantly related to high body mass index [32]. In addition to this, excessively consumed sodium harms organs such as the heart, veins, and kidneys, and leads to diseases such as cardiovascular diseases, cancer, and osteoporosis [33].

In a recent study conducted in Turkey, the mean consumption rates of fruit yogurts, breakfast cereals, biscuits–crackers, chocolates–wafer, and candies in children younger than 24 months of age were found respectively as 55.8, 7.7, 80.5, 52.6, and 25.2% [23]. Moreover, according to the research report of the Monitoring Growth in School Children in Turkey (TOCBI) Project, 25.4% of the children of age 6–10 years consumed sweets, candy, bars, wafers, or chocolate, and 19% consumed chips and popcorn every day [34]. Considering these results, it may be seen that a large part of the daily required intake of energy, fat, and Carbohydrate is satisfied by these foods with low nutritional value, and the role of excessive and frequent consumption of these foods in childhood obesity becomes clear.

Consequently, the energy, fat, and sugar contents of foods sold in supermarkets and targeted for children were found excessive. Among the 435 packaged foods investigated in the study, the products exceeded the limits designated in the health codes declared by the Turkish Food Codex Labeling Directive in 83.4% of the instances in terms of sugar, 93.7% of the instances in terms of total fat, 92.4% of the instances in terms of saturated fat, and 70.3% of the instances in terms of sodium. In addition, in children’s channels, advertisements are frequently broadcast for these foods also known as ‘junk food’ that have high-energy, sugar, saturated fat, and salt contents, and low nutritional value. As a result of recording the advertisements broadcast on the four most frequently watched channels in Turkey for 4 days including 2 weekdays and 2 weekend days, it was observed that 32.1% of all advertisements were food advertisements, and 81% of these advertisements were those of unhealthy products that contain high amounts of energy, fat, and sugar. The same study found that 30% of the unhealthy product advertisements were targeted for children using audio-visual techniques [35]. Again, offering gifts for consumption of these foods or including cartoon characters that children like on the packages of these products encourages the purchase of goods and, therefore, increases the consumption of these foods. In this context, in terms of prevention and treatment of childhood obesity, it is of great importance that responsible stakeholders such as relevant offices of government, the food industry, and media cooperate.