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
4 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.
Very interesting study, however the results would be different for participants that are working or have worked night shifts for years.