Stress and overweight/obesity among nursing students

Objective analyze associations between demographic, academic, health, stress, overweight and obesity characteristics among nursing students. Method this is a cross-sectional study with 95 students from a private university in Rio Grande do Sul, Brazil. A demographic, academic and health characterization questionnaire and the Assessment of Stress in Nursing Students (ASNS) scale were applied. Anthropometric measures were taken and descriptive and bivariate analyses were performed. Results female students predominated in this study, mean age: 25.6±5.87 years. Weight gain was observed in 52.6% of the students, with the ‘Professional training’ session reporting high (29.5%) and very high (36.8%) levels of stress. None of the stress scale sessions was associated with overweight and obesity. Conclusion overweight and obesity were associated with male participants, high blood pressure, weight gain since the beginning of the course, altered waist circumference, no physical activity, eating more in stressful situations, and consumption of unhealthy foods.


Method
This is a cross-sectional study that is part of a cohort study project titled Avaliação da Ocorrência The study population had 144 students from the nursing course mentioned above. For sample calculation, this study considered an estimated percentage of 0.5%, 95% confidence interval, and sample error of 0.05%.
Based on this calculation, to ensure a representative sample, the minimum number of participants would be 89 nursing students. However, all 114 students were invited to participate in the study. The inclusion criteria were: students should be regularly enrolled in the nursing course, aged ≥18 years. Students away from academic activities due to medical leave, mobility, temporary course interruption, or for any other reason, were not included in the study.
Data collection was performed between September and December 2016, using non-probability sampling (all of them were invited), as scheduled with the students. The variables collected were: a) Demographic characteristics: sex (female, male), age (in years, and later, they were dichotomized as ≤26 years and ≥27 years), marital status (single, married/stable union), skin color (white, black, brown), with children (yes, no); b) Academic characteristics: course semester and start year; c) Health: weight (kg), height (cm), waist circumference (cm), blood pressure (mmHg), physical activity (no, yes, sometimes), and questions assessing the eating habits of students (11) ; d) Stress of the students, assessed through the scale of Assessment of Stress in Nursing Students (ASNS) (3) .
The ASNS scale has 30 questions that assess the level of stress. Each question has 4 options of answer (0 = I do not experience this situation; 1 = I do not feel stressed with this situation; 2 = I feel a little stressed with this situation; 3 = I feel very stressed with this situation). The ASNS has six sessions: Session 4 'Environment' address the challenges found when accessing the fields of internship or university and the situations of exhaustion perceived by students due to the transportation system used by them. The six items of Session 5 'Professional training' refer to the student's concern about the knowledge acquired during the academic training and its impact on his/her future professional life. It also addresses the perception of situations that may occur in his/her professional life.
The five items of Session 6 'Theoretical activities' address the challenges facing students related to the nursing program content, the activities performed by them and the program methodology adopted by the institution (3) . were not pressing the limb, using a proper cuff size for the arm circumference; the student was sitting with uncrossed legs, feet resting on the floor, back resting on the chair and relaxed (12) .
The first measurement was performed with the student resting for 5 to 10 minutes in a calm environment, making sure the student had no full bladder, not exercised for at least 60 minutes, not consumed alcohol, coffee or food or smoked 30 minutes before the measurement. The second measurement was performed after completing the questionnaire, around 20 minutes between the first and second measurements. The measurement equipment was digital, certified, well calibrated and maintained, and transported properly.
For BP classification, the recommendation of the 7 th Brazilian Guideline of Arterial Hypertension was used, so students were considered hypertensive with systolic BP (SBP) ≥140mmHg and/or diastolic BP (DBP) ≥90mmHg, according to the mean values of the first and second measurements (12) .
Weight at the beginning of the nursing course was self-reported and the current weight was measured were used (1,13,14) . Hypertension (12) , cardiovascular risks were categorized as follows: no risk (<90 cm waist circumference for male and <80 cm for female participants), increased risk (≥90 to <102 cm for male and ≥80 to <88 cm for female participants) and significantly increased risk (≥102 cm for male and ≥88 cm for female participants) (14) .
After double entry of data in an Excel spreadsheet and correction of typing inconsistencies, data were        and self-reported white skin color (78.9%) (18) .
More than half of the study participants report they eat the main meals of the day and do not replace them with quick snacks. The most often meals are lunch and dinner. However, less than half of the students have breakfast and supper. Lunch was also the most frequent

Discussion
The study participants were predominantly female nursing students, in agreement with Brazilian studies conducted by the Federal Nursing Council, showing prevalence of female nursing professionals (87.2%) (16) . They also agree with other findings in the literature regarding www.eerp.usp.br/rlae Urbanetto JS, Rocha PS, Dutra RC, Maciel MC, Bandeira AG, Magnago TSBS.
meal of a study on the lifestyle of nursing students, who reported it four to seven times a week (73.4%) (19) . In this study, students also reported snacks one to three times (45.8%) and four to seven times (24.5%) a week (19) .
The habit of performing other activities (for example, watching TV, using cell phone) while eating meals seems recurrent in the literature. The use of cell phone during meals was reported by 14% of the students, due to the need to remain connected (39.5%) (20) . This is a reason for concern, as the students, when doing other things while eating, do not have a quiet moment to enjoy the food, eat fast, with impact on satiation, not fulfilling their nutritional needs.
Although the number of students with good nutrition is larger (47.4%), weight changes is a concern when the percentages of overweight (35.8%) and obesity I and II (16.8%) are added together, as they reach 52.6% of the students in this study. These findings exceed the prevalence already identified, where 26% of nursing students from a university in Bahia were overweight and 4.5% presented obesity I and II (21) , and combined prevalence of overweight/obesity was 32.4% of health students from two Mexican universities (22) .
The 7 th Brazilian Guideline of Arterial Hypertension (12) emphasizes that weight gain is directly related to increased BP. In this study, almost 50% of the students had pre-hypertension and 26.3% had hypertension.
The changes in waist circumference indicate visceral fat deposition, which is another important factor to be considered in the prevention of health aggravation among nursing students.
Stressful situations can contribute to changes in eating habits, including increased food intake, which predisposes to overweight and obesity in a significant way (22) . The students in this study presented high (29.5%) and very high levels (36.8%) of stress, regarding Session 5 of the ASNS, which assesses professional training issues. Other Brazilian studies also showed greater percentages (around 50%) of stress in this session (23)(24) . Several factors may be related, including concern about increasingly competitive labor market, requiring health professionals to attend specialization courses and acquire theoretical-practical knowledge and experience.
Unlike other studies showing a significant relationship among stress, overweight and obesity (5,22) , the findings of this study did not show statistically significant differences between weight changes of students, according to the BMI classification and the levels of stress evaluated by the ASNS session (p>0.05). Significant relationships were found with some demographic and health variables.
A study that evaluated risk factors for cardiovascular diseases among nursing students associated BMI ≥25 cm in the age groups 21-30 years (25) , unlike this study, which did not show any significant difference between the groups evaluated (p=0.06).
Male participants were significantly associated with BMI in overweight (p=0.03) when compared to female participants, who were classified in the 'good nutrition' category. Among Mexican students, the prevalence of overweight/obesity was also significantly higher among male students (38.5%) than among female students (30.5%) (22)  Waist circumference was associated with BMI (p<0.001); that is, a higher percentage of students with increased cardiovascular risk were classified as presenting overweight (69%) and students with significantly increased risk were classified as presenting obesity (71.4%). In this regard, there is no consensus in the literature, since a study comparing waist circumference and BMI between the first and last year of the nursing course did not find a significant variation of these indicators; however, 59.1% of the students did not have proper waist circumference (21) , which is close to the percentage found in this study (52.6%).
These findings are supported by the fact that students do not consider their eating habits as healthy and do not usually practice physical activity. Those who do not practice physical activity were classified as presenting obesity (27.9%). According to ABESO, modern lifestyle favors weight gain. Eating fast and using cell phone during meals, for example, are obstacles to satiation. Reduced sport practice and lower daily energy expenditure are also mechanisms that influence weight gain, which may be related to lack of time (2) and the dynamics of academic life. A study evaluating the practice of physical activity among nursing students reported 57.8% of the students were sedentary (27) . The 7 th Brazilian Guideline of Arterial Hypertension reports physical inactivity has been considered one of the major public health problems, due to its high prevalence, and because it is the second main cause of death in the world (12) .
The physical consequences of physical inactivity can happen sequentially, since the students classified with hypertension had greater distribution in the categories of overweight (54.2%) and obesity (25%). According to