Tweaking your lifestyle could be a big step towards diabetes prevention.

The American Diabetes Association has published new diabetes prevention guidelines for people at high risk of type 2 diabetes, the most common type of diabetes.

The guidelines appear in September's edition of Diabetes Care. They're accompanied by recommendations for people who already know they have type 2 diabetes.

The bottom line: Your daily habits can tilt you towards or away from developing diabetes, and it's never too late to make a positive change.

Nearly 21 million people in the U.S. have diabetes. That includes about 6 million people who haven't been diagnosed, according to the CDC.

6 Tips for Diabetes Prevention

If you're at high risk for diabetes, here's your to-do list from the new guidelines:

• Lose extra weight. Moderate weight loss -- 7% of your weight -- may cut diabetes risk.
• Cut fat and calories from your diet. That should help with weight loss.
• Skip low-carb or high-protein diets. They may not work out in the long run.
• Get plenty of fiber. Get 14 grams of dietary fiber for every 1,000 calories you eat.
• Go for whole grains. Make at least half your grains whole grains.
• Get regular physical activity. Go for 2.5 hours per week (check with your doctor first).
• The guidelines don't recommend drinking alcohol for diabetes prevention.

Observational studies have tied moderate drinking to lower diabetes risk. But there's not enough data to recommend alcohol for diabetes prevention, according to the American Diabetes Association.

5 Tips for Diabetes Patients

Have you already been diagnosed with diabetes? There are new guidelines for you, too.

The dietary recommendations for people at high risk for diabetes generally apply to diabetes patients. Additional tips for people with diabetes include:

• Eat healthy carbohydrates. Try fruits, vegetables, whole grains, legumes, and low-fat dairy products.
• Limit saturated fats. Get less than 7% of your total fat intake from saturated fats.
• Minimize trans fats. Check nutrition labels on packaged foods for trans fat.
• Curb dietary cholesterol. Get less than 200 milligrams of cholesterol in your daily diet.
• Eat fish at least twice weekly. Fried fish, however, isn't recommended.
• Knowing about glycemic load and glycemic index, which rate carbohydrates' effects on blood sugar, may also be helpful to people with diabetes, according to the American Diabetes Association.

Diabetes Symptoms

Diabetes doesn't always have obvious signs. But possible symptoms include:

• Increased thirst
• Increased hunger
• Fatigue
• Increased urination, especially at night
• Weight loss
• Blurred vision
• Sores that don't heal

The earlier diabetes is diagnosed, the better. Check with your doctor to screen for diabetes. If you already have diabetes, make sure you keep up with recommended tests and checkups.