And if you can handle that - try to cut out all those bad (white, refined, simple) carbs!
So, what's wrong with sugar? Basically, it's all about blood sugar and insulin levels. The Glycemic Index is a rating scale of how the carbs in a food will raise your blood sugar. It is explained here. I am not doctor or nutritionist, but I can share what I've learned through my own research here.
Sugar is in everyday items such as peanut butter and the bread we put it on. It is added to many processed and "healthy" foods. Watch out for packages labeled "low fat." That usually means added sugar for flavor. Avoid pre-packaged and processed foods.
Sugar messes with your body's insulin production. This is why Diabetes is so prevalent and why so many diabetics must take insulin on a regular basis.
Natural insulin is needed to process sugar into energy. Insulin should be able to regulate itself, but our bodies can no longer do this even in the pre-diabetic stage. High insulin levels can affect many other functions of the body. It can lead to high cholestorol levels, extra fat storage, and heart disease.
Here is a video from Active.com about stopping the sugar addiction.