Overnight eating may be putting night shift workers at higher risk of chronic health conditions.
South Australian researchers found blood glucose levels skyrocketed in study participants who either snacked or ate full meals at night putting their health at increased risk.
Led by researchers from the University of South Australia, University of Adelaide and SAHMRI, the research involved a six-day trial with 55 adults in the healthy BMI range who don’t usually work night shifts.
Study participants were divided into three groups: those who fasted at night, those who had snacks, and those who ate full meals.
All participants stayed awake for four nights and slept during the day, with a recovery day on day five to re-establish normal sleeping and eating cycles, and blood glucose testing on day six.
Results showed participants who ate meals or snacks during the night shift had significantly worse glucose tolerance compared to those who fasted.
“We found that blood glucose skyrocketed for those who ate full meals at night and those who snacked, while the people who fasted at night showed an increase in insulin secretion which kept blood sugar levels balanced.
“We know shift workers are more likely to have diabetes, they’re more likely to have heart disease, and they’re more likely to be overweight. Our research suggests that meal timing could be a major contributor to those issues,” said Professor Leonie Heilbronn, from the University of Adelaide.
Insulin sensitivity was disrupted among all participants, regardless of their eating habits, adding to the body of evidence that night shifts cause circadian misalignment and impair glucose metabolism.
“When you eat a meal, your body secretes insulin, and that insulin helps your muscles and other tissues to take up glucose. If you become resistant to insulin, then you can’t take up that glucose as effectively into your muscles and if it continues, that potentially puts you at risk of diabetes.”
Not eating large meals while working night shift and instead eating primarily during the day could be a straightforward intervention to manage health outcomes for many workers, said lead investigator UniSA Professor Siobhan Banks. “This could be easier for people to follow than other more complex diets.”
Future trials will investigate whether eating only protein snacks on night shift is a potential solution to satiating hunger without predisposing workers to negative health consequences.
The study was published in Diabetologia
12 Responses
I was a night shift worker for 25 years. For the first half of those years, I swapped back to a day wake/night sleep pattern on my nights off. For the second 12 and a half years, I simply stayed on the night sleep pattern during my nights off. i.e. into bed at 6-7 am, sleep until 2-3 pm, awake again until 6-7 am.
This worked for me as meal times were regular – largest meal in the evening, lunch type meal around midnight and light ‘breakfast’ around 4 am.
Further research into the impact a continuous night shift sleep/wake cycle has on insulin/BSL’s and cortisol levels would be interesting.
I was a nurse for 45 years. I am now 69 years ols and now nurse aid and love it. I have, for around 15 years, been working the night shift both as a nurse and now as an aid. I do not eat on my shit but try to drink at least 2 litres of water and enjoy 2 coffees. Getting out in the day and also trying to get in a couple of walks helps. I feel very lucky that I do not require any medications.
Be careful, Night Shift Workers, I am a Retired Registered Nurse , Midwife and Director of Nursing who worked Night Shifts. I cannot remember what food I ate during the shift.
As I result I have developed Severe I.B.S. It is debilitating Disease that has no cure, only daily management.
I believe I.B.S. is afflicting some of the Medical Profession.
When I was doing my Midwifery Training, I worked 19 weeks of the year on Night Duty.
We lived in the Nurses Home then. My room backed on to the Flinders. St. ( Melbourne )Tram lines. Noisy.
We had to get up to attend Specialist Lectures, usually 2pm in the afternoon. Happy Days.
Have a look i to the Carnivore diet for your IBS. Some swear the it helps.
Very interesting study, however the results would be different for participants that are working or have worked night shifts for years.
All these risks, why aren’t we getting paid a risk benefit for our commitment?
It amazes me that people still believe that night shift nurses are sedentary and just sit at the nurses station. After 30 plus years of shift work, my night shifts are now often busier than the day shift! How am I supposed to keep my energy levels up if I’m fasting?! I still have my 2 entitled breaks on night shift, and on one of those I have a toasted sandwich or a bread roll, plus copious amounts of coffee! We are very poorly compensated for working nights (the penalty rates are atrocious), maybe we should be getting paid “danger” money too. More research into this area is definitely necessary.
Is this about nurses only going night shifts? What about us who swap around on a weekly basis. Day shifts and night shifts every week. Not rested enough when starting morning shifts and wanting to sleep when going nights. Unable to keep a semblance of a routine regarding sleep cycles or meal times.
I’m seventy now and work full time shift work on a busy hospital ward. My nights are two a fortnight then the other shifts either mornings or afternoons. I usually fast overnight or have minimal intake, other than coffee. I check my BSL at about 4am fairly regularly, it’s always between 4.0 and 5.0mmol/L. I thought it was well known that nights were bad for our health, but that is the job. Generally I stick to the same meal pattern as during the day and it seems to work. We are so busy overnight that we don’t take breaks on the ten hour shift, so by not eating I can use up the calories from the day. It’s whatever works best for you, but I have found this is the best.
It would be interesting to see the age ranges and [demographics] of participants. Did the participants have sleeps on their breaks? Were they rotating from nights to days or more permanent night shifts? So many possible variables.
I cannot go a whole shift without eating and still function on a safe level for myself and patients.
Agree. And also the health of the individual to begin with – lifestyle, BMI, genetics….
Interesting study, wonder what it would be like in a months time of doing night shift or if the participants were tested again a month post the experiment and going back to their other shifts, whether there was a rebound effect.
Been nursing in some way or form for 19years, When doing night shift I try to have a big meal before I leave the house and have a little snack on the shift with drinking fluids (like white/green tea and water) helps continue the shift. I only allow myself to have one black tea (with milk) a day in the morning or when I wake up. I do mostly pm and night shift though, refuse to do quick changes – I have had to remind rostering people about this multiple times – latest Hb1ac was 4.1.