Insulin is a hormone made by your pancreas that acts like a key to let blood sugar into cells for use as energy. If you have prediabetes, the cells in your body don’t respond normally to insulin. Your pancreas makes more insulin to try to get cells to respond. Eventually your pancreas can’t keep up, and your blood sugar rises, setting the stage for prediabetes—and type 2 diabetes down the road.
#1. LEGUMES—Diets rich in legumes—soybeans, black beans, kidney beans, lentils, pinto beans—are good for your blood sugar levels both short-term and long-term. The secret? "Resistant starches," which resist digestion in the small intestine and go straight to the colon, feeding the bacteria in your gut and in the process improve your body's response to insulin.  (These resistant starches are also in green bananas, uncooked oats, and potatoes that have been cooked and cooled. Rejoice, potato salad lovers who can control their portions.)

Eat healthy foods. Plan meals that limit (not eliminate) foods that contain carbohydrates, which raise your blood sugar. Carbohydrates include starches, fruits, milk, yogurt, starchy vegetables (corn, peas, potatoes) and sweets. “Substitute more non-starchy vegetables into your meals to stay satisfied for fewer carbohydrates and calories,” Compston says.
Recently, evidence suggested a link between the intake of soft drinks with obesity and diabetes, resulting from large amounts of high fructose corn syrup used in the manufacturing of soft drinks, which raises blood glucose levels and BMI to the dangerous levels.38 It was also stated by Assy39 that diet soft drinks contain glycated chemicals that markedly augment insulin resistance. Food intake has been strongly linked with obesity, not only related to the volume of food but also in terms of the composition and quality of diet.40 High intake of red meat, sweets and fried foods, contribute to the increased the risk of insulin resistance and T2DM.41 In contrast, an inverse correlation was observed between intake of vegetables and T2DM. Consumption of fruits and vegetables may protect the development of T2DM, as they are rich in nutrients, fiber and antioxidants which are considered as protective barrier against the diseases.42 Recently, in Japanese women, a report revealed that elevated intake of white rice was associated with an increased risk of T2DM.43 This demands an urgent need for changing lifestyle among general population and further increase the awareness of healthy diet patterns in all groups.