Your fasting level is well above 126, which is the minimum for diagnosing diabetes. There is no such thing as a "port lunch" reading. I suppose you mean "post lunch" - i.e. after eating lunch. That 171 reading is above the normal limit of 140 after meals, but far below the level of 200 which would indicate diabetes. In other words you have two conflicting readings. The 154 says you already have diabetes, but the 171 would suggest you are only borderline - also known as prediabetic. Because of the conflicting readings, and also because diabetes is never diagnosed based on just a single blood test, you should see your doctor and schedule a follow-up test to see where you actually stand. Until then, you have to realize that both the 154 and 171 readings are above normal. Regardless of whether you are actually diagnosed with diabetes, your doctor will most likely want you to cut down on the amount of carbohydrates in your diet, exercise more, and lose weight if you are overweight. Those are all good suggestions for dealing with high blood sugar. Good luck and best wishes.