Glucose levels and glucose-test results, Glucose Chart
Blood glucose levels give you an indication of whether your blood sugar is too low, too high, or just right. Tracking these levels is important if you're managing diabetes or simply striving for optimal health because maintaining healthy levels helps reduce your risk of many common, life-threatening diseases, including diabetes, heart disease, stroke, cancer, Alzheimer’s, and Parkinson’s.
On the ketogenic diet and in general, glucose testing is a good way to identify foods that significantly trigger blood-sugar spikes in your body. Blood sugar changes far more rapidly than ketones (ketones are slow to move and sometimes it's what happened the day before that matters most). We suggest you take a baseline test before a meal and then test again at 30, 60, and 120 minutes after eating, to determine whether certain foods are causing your glucose to spike. (You can also just do a baseline test and follow up with another test at 60 minutes.)
Generally speaking, you don't want your blood sugar to spike more than 30 mg from your baseline, and ideally your blood sugar should return to baseline within 2 hours; if it doesn't, you may be having an insulin response to that food and may want to consider reducing or eliminating it from your diet. With this knowledge, you can direct your diet away from foods that adversely affect your glucose levels and more toward foods that work best with your body.