Managing Diabetes on Shift Work

Shift work makes diabetes harder for a reason that is physiological rather than behavioural: your body's internal clock expects food and sleep at particular times, and night work asks it to do the opposite.

The research is reasonably clear on the size of this. Reviewing the evidence on circadian disruption, shift workers carry about a 9% higher risk of diabetes than people who have never done shift work, with roughly a 5% increase for every five years of it. Rotating shifts appear worse than fixed nights. In controlled experiments, deliberately misaligning the body clock raised post-meal glucose by about 6% even with identical food.

None of that means you should leave your job. It means the extra difficulty is real, and not a failure of effort on your part.

What helps

• Keep medicine timing anchored to the clock, not the shift, unless your doctor has told you otherwise. If you take insulin, ask specifically how to handle rotating shifts.
• Eat your main meal before the shift, not at 3 am. Night eating reads higher.
• Take the same food to work every night. Canteen and vending options at 4 am are the worst available.
• Protect sleep length, even if the timing is unavoidable — dark room, phone away, same duration each day off.
• Test more often when your shift pattern changes, which is when readings move most.

Fixed shifts are easier than rotating ones. If you have any say in your roster, that is the thing worth asking for.