It depends on the type of blood sugar test. Fasting blood sugar of 126 mg/dl or more, post prandial blood sugar of 200 or more is considered to be Diabetes.
Glucose should only be given to Diabetic patients when they are in hypoglycemic state i.e., when the blood sugar levels have dropped below normal range and patient is symptomatic.
Leading a better lifestyle in the form of avoiding excessive sugar/ fats, high fibre foods, breaking sedentary life and regular physical activity helps in lowering the blood sugar levels.
Each person's story and journey of handling diabetes is different. One thing which is mostly common is that with good diet, lifestyle changes, exercise and medications, most patients could lead almost a healthy lifestyle.
Foods to avoid include fried foods and other foods high in saturated fat/ trans fat, foods high in salt, sweets such as baked goods/ candy/ ice cream, beverages with added sugars such as juice/soda/sports or energy drinks.