Results from this research are similar to those from studies done in neighborhood countries [3, 11, 6, 12, 13] probably due to the similar geographical, social and cultural characteristics. In addition, comparison with some larger health and nutrition surveys [14, 15] is possible even though Bosnia and Herzegovina belongs to low-to middle income countries.
Since the study population was mature enough (17 and 18 years old), they showed good knowledge about nutrition and related terms as expected. Results are in accordance with similar research [3] where girls also showed better knowledge.
According to guidelines for adolescence, adolescents should have 5 to 6 meals per day (3 main meals and 2 to 3 snacks) to ensure adequate amount of energy for all daily activities. When an adolescent’s overall energy and nutrient needs are not met, linear growth may be slowed, stunting may occur, and sexual development and menarche may be delayed [2]. Out of all participants, 77.4% have 3 to 5 meals per day. This finding is consistent with those of other studies on similar population. In research [11] on student population in the city of Mostar, most common response was 3 to 5 meals per day between participants (48.63%, of which 49.32% of males and 38.36% of females). We observed similar difference in genders results (Fig. 1). But overall results are better in this research. Reason could be in age difference between studied population, where respondents from research of Banožić et al. [11] are university population in Mostar, with different obligations during the day. Results from this research are more similar to the results of the cross-sectional AVENA study, which included 1978 adolescents from five Spanish cities. Results from AVENA study show that 80.4% of boys and 75.9% of girls have four or more meals during the day. This study also showed that adolescents eating more than four meals per day had lower skin folds and waist circumference [14]. A several observational studies showed a consistent association of skipping meals with increased obesity risk in children [16]. Therefore, increasing meal frequencies to 5 per day with adequate nutrition quality could be a possible target for early prevention of overweight and obesity, and consequently chronic non-communicable diseases [16].
Relatively low percent of students (35.7%) does not consume breakfast half to one hour after waking up regularly (Table 4). That is in accordance with results of [13] research on 229 high school students between 15 and 18 years old at Travnik also in Bosnia and Herzegovina. In that research 37.78% of males and 32.37% of girls does not consume breakfast regularly. In another research in Banja Luka, Bosnia and Herzegovina [12] only 25% of 119 high school students breakfasting on regular basis. Research [3] on 117 adolescents shows that 36.8% of high school students from continental part of Croatia skip the breakfast. According to some researches, breakfast consumption has been associated with improved cognitive performance, tend to lower body mass index (BMI), bone and cardiovascular health of eaters, and exhibit a healthy weight control than at breakfast skippers. Conversely, breakfast skippers tend to have higher BMI, poorer food choices and greater energy intake from snacks [17, 18, 19]). In the large Iranian study of 78,905 university students aged 18 years and older, male students who consumed breakfast frequently had higher intake of fruits, dairy, and lower intake of fast foods and carbonated beverages than those who consumed it infrequently [20].
Conclusion from the Third National Health and Nutrition Examination Survey [18] was that not only breakfast consumption itself is associated with BMI, but also the type of food eaten for breakfast, affects BMI. Eating cereals or quick breads for breakfast is associated with significantly lower body mass index compared to skipping breakfast or eating meats or eggs.
An adequate intake of water for 17 and 18 years old boys and girls is 2 liters per day, including drinking mineral water and water contained in food [21]. That is the same as for adults older than eighteen. Water is a nutrient essential for life and health. Even minor losses can have adverse effects on body thermoregulation and physical activity capacity, feelings of fatigue, concentration and alertness and cognitive function [22], what is especially important for school children and students. The results for water intake between genders are very similar to the results [11] and for high school population in Serbia, Belgrade [6] where 45% of boys and 47% of girls drink 1 to 1.5 L of water per day. According to [11], girl teenagers consume in average smaller amount of water than boys. The most common response, in this survey, between girls (47.3%) was 0.5-1 liter per day, what is equivalent to 6 glasses of water, and the most common response between boys (58.4%) was 1.5-2 liters per day what is equivalent to 8 glasses. This may be due to different physical needs for water between genders. According to this survey, girls are less physically active than boys so explanation could be find in their lower needs for water.
Consumption of soft drinks is in accordance with other surveys on similar population [11, 13]. According to [3] on high school population in Vinkovci, Croatia boys consumed soft drinks more often than girls (47.7% vs. 36.1%), as in this research (47.7% of boys vs. 44.3% of girls). Regular intake of soft drinks increase energy intake, what can contribute to obesity and risk of NCD. Findings from well-powered prospective cohorts have consistently shown a significant association and a direct dose–response relationship between sugary beverages consumption and long-term weight gain and risk of type 2 diabetes [23]. Calorically sweetened beverages contribute to obesity through their caloric load, because intake of sugary beverages or beverages with high-fructose corn syrup does not produce a corresponding reduction in the intake of other food, so beverage calories are “add-on” calories. Soft drinks have also been implicated in the risk of the development non-alcoholic fatty liver disease and insulin resistance [24]. This is a reason why mineral water needs to be the first choice for children and adolescents to quench thirst.
Cereals and cereal products were rarely eaten (51% of participants eat less than one time per week) (Fig. 3) and that finding is consistent with similar study [13]. Among 229 participants aged 15 to 18 years, there was 30.1% of students who never consumed cereals, 31.9% of them consume it 1 time per week, 18.3% 2 to 4 times per week, and 19.7% for 1 and few times every day [13]. Question about whole grain consumption, was not included in other similar surveys done in Bosnia and Herzegovina. Most data come from US but it was also including in some survey in Europe. For example, in large Italian INHES study on sample of 561 children and adolescents (5–19 years old), 62.6% of all girls and boys were non-consumers of whole grain food, 15.5% were occasional consumers (< 1 time/ week) while 21.9% were regular consumers (≥ 1time/week) [15]. In the UK 15% of children and teenagers do not consume whole grain at all, and in Germany for the same population that is 19% [25]. In numerous epidemiological studies consumption of whole grain products is associated with lower risk of chronic diseases such as coronary heart disease, stroke, diabetes type 2 and colorectal cancer. It also has positive health benefits through regulating blood pressure, insulin sensitivity and plasma cholesterol [15]. The Mediterranean diet pyramid recommends the consumption of one or two serving of cereals at each meal, in the form of bread, pasta, rice, couscous but preferably whole grain. Taking into consideration that whole grain products have higher levels of dietary fibers, vitamins (B vitamins), minerals (zinc, phosphorus, magnesium, iron) and bioactive compounds such as antioxidants and other phytochemicals, they must be included in adolescent`s daily diet. Foods high in dietary fibers, such as whole grain cereals and vegetables, can promote satiety and therefore may have influence in weight regulation by improving appetite regulation and tending to constrain excess energy consumption during the day [25].
Having in mind recommendations for vegetables and fruits consumption (5 portions of 400 g a day) results are not satisfactory (Table 5). In similar research [12] on 119 students in another city in Bosnia and Herzegovina, 39.5% of participants consumed vegetables once a day, 23.5% twice a day and 10.9% 3 times a day. Considering fruits consumption, 22.7% of participants consumed fruit once a day, 31.3% twice and 16.8% three times daily in the same study. In study [11] the most common response for consumption vegetables and fruits was 2 to 4 times per week, for both males and females. Vegetables and fruits supply vitamins and minerals to the diet as also dietary fiber, phytochemicals that function as antioxidants, phytoestrogens, and anti-inflammatory agents and through other protective mechanisms. Therefore consumption of vegetables and fruits is linked to lower incidence of chronic diseases [26].
Analysis of the collected data, shows that 66% of adolescents consume dairy products every day. The similar results are obtained in the study [12] where 59.7% of adolescent population consumes milk and dairy products on a daily basis. Products as milk, yogurt and cheese should be on a daily menu of young boys and girls. Recommendations are approximately three to five servings per day for adolescents, encouraging low-fat dairy products. Decreased milk consumption negatively influences calcium and vitamin D intake, which are important for bone development, dental integrity and maintenance of healthy body composition [27].
Regarding adolescent’s consumption of red meat results are not wanted (Table 5). Similar to the study [12], adolescents have dietary preferences to consume red meat mostly up to 3 times per week. For children, meat is important source of valuable proteins, vitamins A, B1, B12 and niacin, iron, zinc and other micronutrients [28]. For adolescents aged 17 and 18, recommendations as for adult healthy population could be applied. Evidence from last decade point out connection between increased consumption of red meat, especially in its processed forms and health effects, especially for cardiovascular and cerebrovascular health [28]. In most cases, the muscle meat from beef, veal, pork, lamb, venison is defined as “red” meat. Recommendation is also to moderate consumption of processed meats because these are high in fat and salt, classified as Group 1 carcinogens for humans, based on epidemiological studies. The strongest, but sill limited, evidence suggest that eating processed meat causes colorectal cancer, and some evidence links it with pancreatic and prostate cancer [29, 30].
Considering that 33.2% of young participants have someone in immediate family with some chronic non-communicable disease (DMT2, hypertension, or some other cardiovascular disease) more attention should be paid on consumption of this food group, but also for group of oils and fats. Very large percent of adolescents prefer butter, which is saturated fat, and can influence a total cholesterol level in blood and consequently have association with NCD. According to Mediterranean diet, mono and polyunsaturated fatty acids (olive oil) reduce blood cholesterol level and risk of heart diseases when they substitute one portion of saturated fatty acids in the diet. Consumption of olive oil reduces LDL cholesterol simultaneously affecting HDL cholesterol [31].
Since 12.9% participants answered that follow some other “special diet”, mostly boys, we supposed that maybe they followed some ketogenic diet (because of popularity and more physical activity), but more detailed survey should be carried out to confirm this.
Girls are more susceptible to reduction diets in this survey as also in similar survey [3]. Also interesting facts are that girls had more allergy or food intolerance than boys. There are no such results from similar researches from neighbor countries but there is also a small number of other studies about allergy or food intolerance prevalence in adolescent population. Conclusion, from the Isle of Wight Birth Cohort (n = 1456) on prevalence and longitudinal trends of a food allergy, is that food allergy is highly prevalent in infancy with partial resolution during late childhood. A number of children acquire new food allergy during adolescence, resulting in a relatively higher prevalence at 18 years [32]. That newly acquired allergy is often result of primary sensitization to inhalant allergens with subsequent sensitization to cross-reactive allergens in food [33]. Since this was in the form of single question in this survey, further investigation about type of allergy and intolerance is needed.
Boys are physically more active than girls (Table 6), which was also showed in other studies [14, 6]. In above-mentioned AVENA study connection between physical activity and obesity development was shown [14].
Limitations of The Study
There was any question about consumption of fish and student’s preferences about it. That is extremely important in adolescent’s diet and for assessment of their dietary habits.