Hi. Having a better diet may slow down becoming diabetic and it will help control your blood sugar if and when you do become diabetic. The GPs advice to cut down on carbohydrates is good advice and unusual for the NHS. You need to move towards high-fibre, low-GI carbs spread throughout the day and perhaps below 150-200 gms/day. This means avoiding highly processed flour based products such as white bread, pasta, pastries and so on as these are absorbed quickly into the blood stream causing blood suagr peaks that your insulin doesn't manage too well. Obviously avoid products with high levels of sucrose. If you are overweight you will probably be insulin resistant and losing weight will help reduce this. You can have fats in sensible quantity preferably unsaturated such as fish etc. Exercise is also very important.