Pre diabetes is based on a level of blood glucose (sugar) above the range considered as normal but still below full Type 2 diabetes.
Many of us have reversed or got into remission with much higher levels than this by restricting carbohydrate (not just added sugar, but think first about bread, rice, potatoes, cereals and pasta too).
I was very strict at first, bought a meter and measured before and after meals to check how many carbs I could eat but still get my BG down into the normal range.
I eat about 110 to 120g of carbs a day now I'm in remission, but we all vary. A lot of my carbs go in milk for coffee and the bedtime chocolate fix!
I start with a low carb 'porridge' based on milled flaxseed and chia, but if you like cooked breakfasts think eggs, bacon, cheese, mushrooms.
I have coffee with double cream or some full-fat milk.
Then I either miss lunch and just have more coffee, or have a light snack - today that was a hardboiled egg with salad. (You can add a dressing made with olive oil or a sugar free real mayonnaise.)
Dinner is usually chicken or fish with plenty of green veg and cauliflower rice or a low carb alternative. Followed by full fat Greek yogurt and a few raspberries or a fake 'crumble' made with berries or rhubarb topped with ground almonds served with cream.
Bedtime is coca with cream and a little 85% dark chocolate.
I do make a low carb cake sometimes, and have a small piece instead of lunch - particularly if I'm travelling.
For my last birthday I made a low carb fruit cake using cranberries and rhubarb I'd dried in a layer of Erythritol then stored in the fridge
Healthy unprocessed or lightly processed fats are good - and usually no need to count calories or restrict fats and protein so you go hungry any more.