Abstract
Background
Urban bus operators are an occupational group with high rates of overweight and obesity. Understanding methods bus operators use for weight control may be important; there may be increased risk for these workers to engage in less healthy weight management behaviours due to stressful working conditions.
Aims
To examine the prevalence of unhealthy and healthy weight control behaviours used by bus operators and examine associations between use of unhealthy weight control behaviours and work-related and sociodemographic variables.
Methods
Bus operators from four different transit garages were invited to complete a self-administered survey; height and weight were measured by research staff. Unhealthy and healthy weight control behaviours, work hours, work schedule and social support were measured with self-report items on the employee survey. Logistic regression analysis was conducted to estimate associations.
Results
Nearly 60% of bus operators endorsed at least one unhealthy method; over 50% reported skipping meals, 30% fasted and 10% reported taking diet pills in the past year. Bus operator gender, race, body mass index status and hours worked per week showed significant associations with using at least one unhealthy weight control behaviour.
Conclusions
Worksite interventions should emphasize the benefit of healthy eating and physical activity but should also address the use of less healthy methods for weight control for individuals employed in transportation occupations.
Keywords: obesity, bus operators, weight control behaviour, work hours
Introduction
Motor vehicle operators, including urban bus operators, are an occupational group with high rates of overweight and obesity. Previous studies have found the prevalence of overweight to be as high as 63%, with overweight being a risk factor for several chronic diseases among these workers [1]. Understanding the methods bus operators use for weight control are important, as these workers may engage in less healthy weight management behaviours. Bus operators experience working conditions such as long working hours, variable shifts, time pressure and low social support [2], which may make it difficult for them to engage in healthy habits for weight loss and weight maintenance. Previous research indicates that male bus operators have lower levels of physical activity and higher fat intake than males in other occupations [3].
Minimal research has examined methods used for weight control in such at-risk occupational groups and the potential association with characteristics of the work environment. Such associations may be worthwhile exploring; one study of hospital workers found that working full time and second and third shifts resulted in reduced likelihood of trying to lose weight [4]. The purpose of this study was to examine the prevalence of specific unhealthy and healthy weight control behaviours used by bus operators. In addition, we examined associations between bus operators’ work schedule, their perception of the social work environment regarding weight management and use of unhealthy in addition to healthy weight control behaviours.
Methods
Data for this study were collected as part of a worksite environmental obesity prevention intervention for Metro Transit workers [5]. Transit workers were recruited from four different transit garages in a Midwestern US city. All employees were invited to complete a self-administered survey; height and weight were measured by research staff. The current study was limited to those transit workers who were employed as bus operators and who completed the baseline measurement assessment. This study was approved by the University of Minnesota IRB Human Subjects Protection Program.
Unhealthy and healthy weight control behaviours were measured with self-report items on the employee survey. Participants were asked whether they had undertaken any of 10 behaviours (7 healthy, 3 unhealthy) for weight control during the past year. Participants self-reported the number of hours worked per week, number of different shifts worked (e.g. 8-h shift/straight hours, split shift), how supportive their co-workers were of weight management behaviours and sociodemographic variables. Body mass index (BMI) was calculated as weight (kilograms)/height (square metre).
The percentage of bus operators reporting past year use of each weight control behaviour was calculated. Logistic regression analyses were conducted to estimate associations between predictor variables (work characteristics, sociodemographics, BMI) and the dependent variable: endorsing past year use of at least one unhealthy weight control behaviour.
Results
Seven hundred and ninety-six bus operators completed the baseline measurement assessment. The participation rate from the four garages ranged from 69 to 84% (N = 796). The prevalence of obesity was high in this sample; mean BMI was 32.7 kg/m2 and 58% were classified as obese. Table 1 presents the percentage of bus operators endorsing each unhealthy and healthy weight control behaviour. Nearly 90% of operators reported using at least one behaviour during the past year. In addition, nearly 60% of bus operators endorsed at least one unhealthy method; 52% skipped meals, 30% fasted and 10% took diet pills in the past year.
Table 1.
Past year use of weight control behaviour among bus operators N = 796 may be slightly variable due to small amounts of missing data
| Weight control behaviour | Total, n (%) |
| Healthy behaviours | |
| Reduce amount of food eaten | 534 (69) |
| Increase fruits and vegetables | 534 (68) |
| Cut out sweets and junk food | 531 (68) |
| Increase exercise levels | 530 (68) |
| Decrease fat intake | 499 (64) |
| Cut out between meal snacking | 484 (62) |
| Reduce amount of calories eaten | 481 (62) |
| Unhealthy behaviours | |
| Skip meals | 406 (52) |
| Fast or go entirely without food (at least 24 h) | 236 (30) |
| Take diet pills (appetite suppressants) | 81 (10) |
| Summary valuesa | |
| Healthy behaviours | 320 (41) |
| Unhealthy behaviours | 459 (59) |
Healthy behaviours refer to bus drivers’ endorsing any of the behaviours listed in the healthy behaviours category only (i.e. not any unhealthy behaviour). Unhealthy behaviours refer to bus drivers endorsing at least one of any of the behaviours listed in the unhealthy behaviours category.
The number of hours worked per week, participant gender, race and BMI status showed significant associations with endorsing at least one unhealthy weight control behaviour (Table 2). Compared with bus operators working <40 h/week, those working 40–49 h/week were more likely to report using at least one unhealthy behaviour (P < 0.05). To explore this further, we performed logistic regression analyses of each individual unhealthy weight control behaviour. Of the three unhealthy behaviours, only meal skipping showed a significant association (i.e. bus operators working 40–49 h/week were more likely to report skipping meals compared with those working <40 h/week). In addition, female operators (P < 0.01), non-whites (P < 0.01) and those classified as obese (P < 0.05) were more likely to engage in at least one unhealthy weight control behaviour.
Table 2.
Association between work-related characteristics and sociodemographic variables and endorsement of at least one unhealthy weight control behaviour among bus operators
| Characteristic | n | % | ORa | 95% CI |
| Age, mean (SD) | 778 | 47.4 (10.5) | 0.99 | 0.97–1.01 |
| Gender | ||||
| Male | 588 | 55 | 1.0 | – |
| Female | 191 | 70 | 1.98 | 1.33–2.94 |
| Income | ||||
| <50001/year | 372 | 60 | 1.0 | – |
| ≥50001/year | 394 | 57 | 1.1 | 0.78–1.54 |
| Education | ||||
| Up to high school | 354 | 58 | 1.0 | – |
| Some college | 308 | 61 | 1.19 | 0.84–1.68 |
| College or higher | 111 | 56 | 1.16 | 0.72–1.87 |
| Race | ||||
| White | 459 | 53 | 1.00 | – |
| Non-white | 320 | 68 | 1.79 | 1.24–2.57 |
| BMI | ||||
| Normal/overweight | 323 | 53 | 1.0 | – |
| Obese | 455 | 64 | 1.53 | 1.11–2.12 |
| Hours worked/week | ||||
| <40 | 206 | 54 | 1.0 | – |
| 40–49 | 499 | 60 | 1.52 | 1.02–2.26 |
| ≥50 | 68 | 60 | 1.23 | 0.65–2.31 |
| Number of shifts | ||||
| 1 Shift | 491 | 58 | 1.0 | – |
| ≥2 Shifts | 259 | 61 | 0.94 | 0.66–1.34 |
| Co-worker support for weight management | ||||
| Not supportive | 569 | 57 | 1.0 | – |
| Somewhat/very supportive | 155 | 64 | 1.18 | 0.79–1.76 |
N = 675 in the logistic regression model due to small amounts of missing data in sample. CI, confidence interval, OR, odds ratio. Bold ORs indicate significant associations.
OR is adjusted for age, gender, income, education, race, BMI, hours worked, number of shifts, co-worker support for weight management.
Discussion
We found that high numbers of bus operators utilized multiple methods to control their weight. Use of both healthy and unhealthy weight control behaviours was similar to and often higher than general population-based samples [6] as over half of the bus operators reported engaging in at least one unhealthy weight control behaviour. Working 40–49 h/week was associated with using unhealthy methods for weight control along with being female, non-white and having a BMI ≥30 kg/m2.
Our findings are consistent with and expand on the results of previous studies. Little to no prior research has explored associations between work-related variables and engagement in behaviours for weight control. Our results indicate that moderate levels of overtime work (i.e. 40–49 h/week) may put bus operators at risk for engaging in unhealthy methods to control their weight, such as skipping meals. It may be that longer hours spent behind the wheel impede abilities to consistently eat healthy foods and maintain physical activity, which may encourage bus operators to supplement weight control efforts with less healthy, yet easier, methods. Research in other occupations has found associations between long work hours and poorer dietary intake and reduced exercise [7]. Consistent with prior research, females, non-whites and those classified as obese were more likely to report using unhealthy behaviours for weight control [6, 8, 9].
Strengths of this study include a large diverse sample of urban bus operators and examination of a wide range of behaviours for weight control. Our analyses are limited by the exclusion of other work-related characteristics that may impact methods used for weight control (e.g. job stress). Although associations were identified among bus operators working 40–49 h/week, no association was found among those working ≥50 h/week. As only 9% of bus operators were in this category, we may have not had the power to fully test this association.
The relatively high endorsement of unhealthy weight control behaviours is concerning. Use of unhealthy weight control behaviours is associated with poor nutrient intake [10] and weight gain over time [9]. Worksite interventions should address the use of less healthful methods for weight control, particularly in occupations with difficult working conditions. Future research should continue to study the methods used for weight control in occupations with high obesity prevalence in order to inform workplace programs and policies addressing obesity.
Key points
Bus operators have among the highest prevalence of obesity among major US occupational groups and suffer from stressful work conditions that may put them at risk for unhealthy weight control behaviours. Nearly 60% of bus operators reported using at least one unhealthy method to control their weight.
The number of hours worked per week was associated with using unhealthy weight control behaviours, along with bus operator gender, race and weight status.
Funding
National Institutes of Health (NIH R01 HL 079478).
Conflicts of interest
None declared.
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