Eating Low Glycemic Before Surgery
Why surgeons increasingly ask for this, what it's meant to achieve, and how to eat in the weeks beforehand.
"I'm having surgery in September and my surgeon has said to do a low GI diet so I've been googling and here I am."
Your surgeon has a specific reason, and it's worth understanding rather than just complying.
Why surgeons ask
Elevated blood glucose around the time of surgery is associated with higher rates of surgical site infection and slower wound healing. Managing glucose in the perioperative period is a standard part of surgical care for exactly that reason.
If you're having abdominal surgery, there may be a second reason — reducing liver size and visceral fat, which makes some procedures technically easier. That's a common instruction before certain operations.
Ask which applies to you. The answer changes how strict to be and for how long.
How to eat in the weeks before
The structure you'd follow anyway, applied with more attention:
Protein at every meal. Doubly important here — protein requirements rise around surgery and recovery, and muscle is what you'll draw on.
Carbohydrate slower, smaller, at midday.
Dinner protein-and-vegetable led.
Alcohol reduced or stopped. Ask your surgical team about this specifically; many will have a view, and it affects both glucose and healing.
Don't crash diet. Arriving at surgery depleted is worse than arriving a few pounds heavier. If you've been told to lose weight beforehand, ask what rate they want.
The things I can't tell you
Whether to fast, for how long, and what to do about any medication on the day — all of that comes from the surgical team. Fasting instructions in particular are specific to your procedure and anaesthetic, and are not something to take from an article.
If you take diabetes medication, the plan for the day of surgery is a specific conversation to have in advance rather than on the morning.
Afterwards
Recovery needs more protein, not less. This is not the moment for restriction — you're rebuilding tissue.
The same structure applies pointed at maintenance: bigger portions, protein at every meal, carbohydrate present.
Try this week: ask your surgical team the specific reason for the instruction and how long they want it followed. That answer shapes everything else.
Education, not medical advice. Surgical preparation, fasting and medication instructions come from your surgical team.