With the development of the social economy and improvement in the living standards, the eating habits of modern people have undergone tremendous changes compared to the past. These changes are not only reflected in the diversification of food sources and the complexity of processing them, but also in the consumption of fast-food and out-of-home meals. Excessive consumption of high-energy density and ultra-processed foods, fast food and takeaways, inadequate and irregular eating times, and snacking between meals are the main characteristics of the modern diet (1). Dietary patterns characterised by the consumption of red and processed meat, fast food, and sugar-sweetened beverages are considered to be important risk factors for chronic non-communicable diseases such as metabolic and cardiovascular diseases in Chinese residents (2), and the pathogenic effects of unhealthy eating habits are gradually attracting increasing attention.

The main manifestations of unhealthy eating habits are short and irregular meal times, and excessive consumption of fast food and takeaways. Eating too fast can affect the levels of gastrointestinal hormones such as ghrelin, YY peptide, and glucagon-like peptide-1 (GLP-1), and therefore disturb the balance between hunger and satiety (3). Thus, it can lead to redundant energy intake, and glucose and lipid metabolism disorders (4), which would in turn lead to an increased incidence of obesity, diabetes, and metabolic syndrome (MetS) (5). Eating too fast is also believed to be associated with gastrointestinal diseases such as indigestion (6). Out-of-home meals (canteens, fast food, takeaways, etc.) have been shown to be a risk factor for high energy and fat intake, and low micronutrient intake (especially vitamin C, calcium, and iron) (7). People with these habits show a higher prevalence of overweight and obesity (8).

Shift work is thought to be an important contributor to irregular meals in modern society. Shift workers exhibit a significant preference for nocturnal activity, higher intake of high-fat diets and sweets such as candy and sweetened beverages, and disordered temporal eating patterns (irregular timing and frequency of meals, night meals) (9). These unhealthy habits are thought to be associated with the elevation of cardiometabolic risk factors [higher triglyceride and lower high-density lipoprotein (HDL) levels] and increased incidence of chronic diseases (including MetS, obesity, diabetes, and hypertension) (10).

Medical personnel are one of the representative populations of shift work, and previous studies have reported that they have irregular diets and excessive intake of fast foods high in salt, fat, and/or sugar after night shifts (11). Because of the COVID-19 pandemic, physicians are confronted with more working pressure and irregular working arrangements (12). With the emerging problems of work-life balance, physicians are more likely to develop unhealthy eating habits such as fast eating and more out-of-home meals. Previous surveys on physicians’ the health statuses have found that the prevalence rates of obesity and related metabolic diseases [such as hyperlipidaemia and coronary artery disease (13)], and cardiovascular disease [such as hypertension (14)] were higher among physicians than in the general population. However, previous studies have mainly focused on the effects of physical inactivity (15) and sleep deprivation (16), and there are few studies on the association of physicians’ eating habits with their health perception and diseases.

Suboptimal health status (SHS) is a physical state between health and disease, characterised by perceived discomfort, general malaise, chronic fatigue, and low energy (17). Unhealthy eating habits, lack of physical activity, poor sleep quality, and other unhealthy living habits are significantly related to self-perceived SHS (18). We conducted this survey to explore the association between the physicians’ eating habits and their perceived SHS status, micronutrient deficiency-related diseases, obesity, and related metabolic diseases.

Our survey results showed that unhealthy eating habits, including more out-of-home eating, fewer meals at home, irregular meals, and eating too fast were common among physicians. These eating habits were significantly related to the perceived sub-optimal health status and disease occurrence, and even after adjusting for the effects of confounding factors such as sex, age, sleep quality, and exercise on the health perception, the risk of developing SHS and disease among physicians with the above eating habits remained significantly elevated. Nutrition doctors, because of work or life factors, have relatively healthy eating habits and a relatively low prevalence of common and chronic diseases, indicating the importance of healthy eating habits and eating environment for physicians to maintain health.

Previous studies generally believe that physicians have better health awareness and health habits than ordinary people, so they mainly focus on their mental stress and burnout. In recent years, studies have found that the incidence of diseases related to overweight, obesity (16) and dyslipidemia (13) in physicians may be significantly higher than that in the general population. This is significantly related to their long working hours, lack of physical activity and the shift system (21). A study investigating the health habits of police officers, ambulance workers, hospital staffs (doctors and nurses) and office workers found that doctors had significantly higher dining-out rates than those in other jobs, and skipped breakfast more often than office workers (22).

Dining out and fast-food rich diets are often characterised by high-energy density, high-fat, larger food portions, and higher consumption of sugar-sweetened beverages (23), while home-cooked meals involve healthier food preparation methods and more dietary varieties (24). Studies in adolescents and adults have demonstrated that increasing the number of meals at home can improve diet quality and reduce obesity and related diseases (25) due to increased fruit/vegetable and dairy consumption and reduced consumption of sugar-sweetened beverages and unhealthy snacks (26). Our study found that physicians had more meals outside and fewer meals at home, consistent with the results of previous studies (27–29), which demonstrated physicians’ high consumption of fast food and alcoholic beverages and less intake of fruits and vegetables.

Due to irregular meals and limited supply time in hospital canteens (30), physicians usually eat faster and tend to consume more snacks at unusual times (mainly at night) (31). These unhealthy eating habits collectively destroy their energy balance by increasing the serum concentrations of appetite-stimulating hormones (e.g., insulin, glucagon-like peptide 1, and YY peptide) and reducing diet-induced thermogenic effects (32), thus raising the risk of obesity and related metabolic diseases. Circadian rhythm disturbances caused by shift work and excessive intake of ultra-processed foods have also been linked to decreased immune function (33), chronic gastrointestinal dysfunction (34), and increased incidence of breast cancer (35), colorectal cancer (36), and other diseases. These findings are consistent with our results that showed that irregular meals and a short meal duration are associated with an increased prevalence of colds, chronic gastroenteritis/diarrhoea, and tumours.

Our study also found that there were significant differences in eating habits and health status among physicians from different departments. Doctors in nutrition departments had relatively healthy eating habits, and the corresponding prevalence rates of common and chronic diseases were low. This may be related to their relatively regular working hours, day shift work, and relatively comprehensive health knowledge (37). In previous studies, researchers investigated the differences of health habits among people of different occupational types in hospitals, and found that nurses had relatively worse health habits and health status than doctors which was also related to their long working hours, shift work and irregular work schedule (38). Other studies have also shown that the supplying timing of hospital canteens and the quality of meals (30) are important factors hindering physicians’ pursuit of healthy diets.

To the best of our knowledge, the present study is the first to investigate the relationship between the eating habits of physicians and their health perception and diseases. The results suggest a relationship between the increased prevalence of SHS and disease among physicians and their work patterns and eating habits, which may be related to the hospitals’ eating environment. This relationship indicates the necessity of paying attention to physicians’ working pressure and improving the supply of healthy food in hospital canteens to improve the health status and work efficiency of physicians. The “Healthy Canteens” initiative promoted by the Chinese National Health Commission is a meaningful attempt in this direction.

This study also has some limitations. Although the survey covered many departments, obstetrics and gynaecology, internal medicine, and nutrition accounted for more than 60% of the participants, which led to a sex imbalance (women accounted for 83.32% of respondents). Thus, this sample might underrepresent the male-dominated population of surgeons. In addition, Self-reported BMI is somewhat inaccurate, but among physicians it can be calculated more professional and frequent, because doctors usually pay more attention to their health status. Our study was in the form of an online questionnaire, so the participants’ eating habits, health perception and diseases were all self-reported. Thus, information bias cannot be ignored, even if the questionnaires were self-assessments conducted by trained physicians themselves. However, the validity of our questionnaire has been verified by previous survey (20) and can minimize the deficiency of self-reported information.

Eating habits such as frequent eating out-of-home, irregular meals, and eating too fast were common among physicians. These eating habits were significantly related to the occurrence of perceived SHS, micronutrient deficiency-related diseases, obesity, and related metabolic diseases diseases.

The original contributions presented in the study are included in the article/Supplementary material, further inquiries can be directed to the corresponding authors.

Ethical approval was not required for the studies involving humans because this is an observational survey study. Written informed consent for participation was not required from the participants or the participants’ legal guardians/next of kin in accordance with the national legislation and institutional requirements because the questionnaire was filled in anonymously online.

WC contributed to conception and design. YiL, YY, PZ, JL, and QZ contributed to data collection. RL and HL supervised the study. YaL and XX contributed to statistical analysis and interpretation of data. MC contributed to data interpretation and manuscript drafting. All authors contributed to the article and approved the submitted version.

This work was supported by the grants from National Key R & D Program of China (grant number: 2020YFC2005000).

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

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