This study focused on dietary practices, healthy dietary intake, and associated factors among office workers in Sri Lanka. Most of the study participants (81.9%) were females. Although most of the workers in Sri Lanka are males, composition or sex distribution may vary in different sectors (20). Most workers (94.8%) were educated up to the GCE Advanced Level or had completed tertiary education. Posts of development officers and management assistants require a degree and GCE Advanced Level educational qualifications, respectively. The findings of the current study concerning sex distribution and education level are consistent with those of a similar study conducted in the Colombo district (12). Similarly, the percentages of participants using public transport and walking to reach the workplace are consistent with the data from the census of public sector workers in 2016, where 46.7% used public transport, and 5.7% percentage walked to reach the office (20).
The reported mean BMIs were 24.2 kgm− 2, and 56.9% of the participants had a normal BMI, while 31.9% and 6.1% were overweight and obese, respectively (Table 2). A similar study conducted among office workers in the Colombo district reported a mean BMI of 24.11 kgm− 2 (12). A comparable mean BMI (23.8 ± 3.6 kgm− 2) was reported in a study among office workers in South India, which could possibly be due to similarities in their socio-cultural environment, dietary patterns and economic statuses with those of Sri Lanka (21). In contrast, a study conducted among Nepali industrial workers has reported a lower percentage with a normal BMI and higher percentages with overweight and obesity (46.8%, 35.8% and 11.1%, respectively) (22) However, a study of university workers in Saudi Arabia reported a higher mean BMI of 28.3 kgm− 2, with 35.9% of participants having a normal BMI and 31.0% being overweight and 30.7% being obese (23). Many studies conducted in Southeast Asian countries have failed to report mean BMI values, hence, comparison should be attempted with caution as mean BMI values tend to change with the social, cultural and economic context.
The prevalence of NCD remained lower at 11.5% in the current study compared to labour force data (17%) (24). This can be explained by the relatively younger population in the present study, with ages ranging from 23 to 59 years {median = 39.5 years and interquartile range (IQR) = 8)}. In contrast, the labour force data included people over 60 as well. However, the reported values for the prevalence of diabetes and hypertension were lower in this study than in the study conducted in 2017 by Swarnamali et al., involving government office workers in the Colombo district of Sri Lanka. Furthermore, several studies conducted in India, Nepal and Thailand have reported a higher prevalence of chronic NCD among working populations (21, 22, 25). In contrast, a low prevalence of diabetes and hypertension has been reported in a study conducted among state workers in Ethiopia (26). The current study considered only patients with a confirmed diagnosis of chronic NCDs, possibly overlooking the undetected cases. This might have contributed to the low prevalence of chronic NCDs among the study sample.
Consistent with Swarnamali et al. (2017), the current study reports an almost similar mean number of servings consumed from various food groups, except cereal-based and unhealthy foods. However, the method used to calculate servings was not specified in the former study, making comparisons difficult. In contrast to the higher consumption of cereal-based or carbohydrate-containing food in the former study (15.4 servings), the current study reports only a marginally high level of consumption of cereal-based foods. Another large-scale study reported a marginally high consumption of carbohydrates among public-sector workers (13).
Of all food groups, cereal-based food (the main contributor to dietary carbohydrates) was the most consumed food group. Fish, meat, pulses and vegetables consumption was within the range recommended in FBDG-SL. In contrast, fruits, dairy products, nuts and seeds consumption was far below the recommended level.
Comparable studies assessing dietary intake among office workers at the regional level are lacking in the published literature. However, in a study conducted in Vietnam, a marginally low carbohydrate intake among young female workers was highlighted (27). The few existing studies support the low fruit and vegetable intake among office workers. A study among Saudi university employees also highlighted a lower consumption of vegetables and fruits, with only 14% of the participants consumed five or more servings of fruits and vegetables (23). A lower proportion of workers meeting the recommended fruit and vegetable consumption requirements has also been reported in studies in both developing and developed countries (28).
A higher education level has been identified as an important factor associated with healthy dietary intake in several studies (14, 15, 18, 29, 30). However, a secondary analysis of a large cohort of French women reported an inverse association between a healthy diet and university education compared to an education below a diploma (31). The current study failed to show any association between education level and healthy dietary intake. Similarly, socio-economic status was not associated with healthy dietary intake, as identified in many previous studies (29, 31). We believe that the relative homogeneity of the sample concerning education level and socio-economic status may have contributed to the observed lack of association between these variables and healthy dietary intake. This similarity in the contextual factors will make it easier to plan and implement interventions to improve the dietary intake among the office worker population.
The existing evidence on association of age with healthy dietary intake has been inconclusive. Some studies have shown that older age is associated with a healthy dietary intake (31, 32), whereas others have reported the opposite (29, 30). The current study also failed to establish a statistically significant association between age and healthy dietary intake.
Healthy dietary intake was associated with female sex. However, it was not statistically significant (p value = 0.07). Sex or gender has been identified as a factor associated with food choices and healthy dietary intake. A review of nutritional surveys and studies in several Western countries confirms the link between female sex and healthy dietary intake. On the other hand, the same review pointed out few studies that showed no significant association between sex and dietary intake (33). Another study among Mexican Americans showed that young males are more prone for unhealthy eating (34). We believe that low male participation might have resulted in the association which is not statistically significant.
Anthropometric measurements such as weight, BMI, waist circumference and body composition are proven to be associated with dietary intake. A whole grain-based diet with vegetables, fruits, seafood and dairy products was associated with better anthropometric measurements (35). Several studies have highlighted the association of high BMI, overweight and obesity with diets high in carbohydrates, fat and sugar and low in vegetables and fruits (36–38). However, the current study did not show an association between dietary intake and BMI. Similar findings have been reported in a study in Malaysia (39) and among Mexican Americans (34). The former study claims that the homogeneity of the study sample and the study's cross-sectional nature could have led to these findings (39). Therefore, we also believe that the homogeneity of the sample and the study design might have contributed to the current study's findings.
Although the association between unhealthy dietary intake and NCD has been well documented in recent years (5, 7), the current study failed to show such an association. The reported prevalence of NCDs was lower in the study sample than in the labour force data (24). Therefore, we assume that NCD status and undetected cases in the sample might have been underreported.
Previous studies have highlighted that eating together can increase the amount of food consumed and total energy intake (40, 41). Furthermore, meal skipping and a busy work schedule were identified as factors associated with unhealthy dietary intake and poor diet quality through studies conducted in other settings (17, 18, 42, 43). The current study revealed an association of unhealthy diet with group eating and meal skipping during the univariate analysis, however, these variables did not show an association with dietary intake in the multivariate analysis.
Group eating and unhealthy dietary intake were associated differently among males and females. Thus, indicates sex can act as an effect modificatory in the association between group eating and unhealthy dietary intake. Although no previous research evidence was found on the effect modification of sex or gender for association between group eating and unhealthy dietary intake, several studies highlighted the effect of sex or gender in different associations. A study conducted in Brazil showed an association between high salt intake and hypertension where the association was greater in women (44). The association of healthy eating index and hypertension in United States was shown to be inverse Lenier in females while being U-shaped in males (45). A significant interaction was noted between diet quality and gender resulting in changes in BMI among Australian adults (46). Therefore. Sex or gender is considered as an effect modifier for different associations with dietary intake. Further, a network analysis of factors associated with nutrition sex was identified to have a central role in interaction (47). In the current study, the interaction term was not significant in the multivariate analysis and the interpretation must be done cautiously as the male participation for the study was low.
The study was conducted to cover a whole administrative district, and the sample was representative of the office workers. Thus, the study findings can be generalized to all clerical-type office workers. The 24-hour dietary recall was used for dietary assessment, and it was supplemented with a picture guide and computer software to calculate serving sizes. Therefore, the dietary assessment was valid and reliable. However, the relative homogeneity of sample hinders the generalization of results to a broader population. In addition, cross-sectional design also fails to establish the temporality of associations.