Night shift workers are at greater risk of obesity, type 2 diabetes and cardiovascular disease, a dietitian told the Working Hours, Shifts and Fatigue Conference.
Eating during the night, which leads to higher blood glucose and triglyceride (fat) levels than day eating, is a major contributing factor.
Monash University Research Fellow Gloria Leung said even taking into account traditional risk factors such as age and physical activity level, shift workers are still at a higher risk of obesity, type-2 diabetes, and cardiovascular disease. .
To investigate the relationship between the time of eating and blood sugar levels, Monash University researchers ran a lab study, where participants were asked to consume the same pasta meal at different times of a 24-hour day, and their blood sugar levels were monitored for the three-hour period after eating.
When participants ate the pasta meal at 8pm and at midnight, their blood sugar levels were six to nine times higher than when they ate the same meal at 8am.
Emerging evidence also shows that individuals who work night shifts burn less calories over the course of a 24-hour day than day workers. In the long term, this may contribute to steady weight gain.
Small changes make big health improvements
Ms Leung recommended that shift workers:
- try to eat the same number of meals per day, regardless of the type of shift they are working (as having a different daily caloric intake across the week is associated with having an increased body weight and waist circumference)
- when awake, eat every four to six hours and try to have a fasting window of around five hours between 10pm and 6am
- eat a small meal one to two hours before bed if hungry after night shifts (as eating too close to bedtime is a common trigger for stomach upset).
- choose a snack with protein if eating during the night, rather than a big carbohydrate-heavy meal, and fill up with vegetables. Choice of protein snacks should still be food focused; examples include chicken and avocado salad, hard boiled eggs, fruit with peanut butter or vegetable sticks with hummus.
- stay hydrated with water and try to avoid sugary drinks (e.g. energy drinks and soft drinks). Caffeine should be used wisely; having too much and too frequently means that you will need more and more to get the same boost.
- download the healthy convenience meals fact sheet.
- If time permits, consider preparing meals on days off and keep a good supply of healthy snacks at work.
Ms Leung acknowledged the difficulty in eating healthily while on night shift. Battling with fatigue, work environments that don’t support healthy food choices and the tendency of using food as reward can all prompt shift workers to turn to the so-called ‘CCCs’ of night shift: chips, Coke and chocolate.
Experiencing fatigue, even on their days-off, can reduce night shift workers’ ability and motivation to eat healthily.
Lack of food preparation and storage facilities at work, and vending machines often being the only food retail option, further limits evening and night shift workers’ food choices.
Ms Leung encouraged shift workers to make small gradual changes, which would improve health if maintained over time.
Join the weight loss/health improvement study
Ms Leung and her colleagues at Monash University are running an 18-month weight loss study in Melbourne and Adelaide, comparing the effectiveness of different diets in helping shift workers with weight loss and improving their overall health. The study will involve a six-month weight loss program involving regular consultations with a dietitian, followed by a 12-month maintenance phase.
Shift workers who are interested in participating can visit monash.edu/swiftstudy