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The One Test Your Doctor Isn’t Doing That Could Save Your Life

The One Test Your Doctor Isn’t Doing That Could Save Your Life

Insulin resistance doesn’t happen overnight. When most of your diet includes empty calories and an abundance of quickly absorbed sugars, liquid calories, and carbohydrates like bread, pasta, rice, and potatoes, your cells slowly become resistant to the effects of insulin.

Your body increasingly demands more insulin to do the same job of keeping your blood sugar even. Eventually your cells become resistant to insulin’s call, resulting in insulin resistance.

The higher your insulin levels are, the worse your insulin resistance. Your body starts to age and deteriorate. In fact, insulin resistance is the single most important phenomenon that leads to rapid, premature aging and all its resultant diseases, including heart disease, stroke, dementia, and cancer.

Insulin resistance and the resulting metabolic syndrome often comes accompanied by increasing central obesity, fatigue after meals, sugar cravings, high triglycerides, low HDL, high blood pressure, problems with blood clotting, as well as increased inflammation.

Even without these warning signs, one test can determine high insulin levels years or even decades before diabetes develops. Early detection can help you reverse these symptoms, yet doctors rarely use this crucial test that can detect high insulin levels.

Why Doctors Miss the Initial Warning Sign of Insulin Resistance

Doctors have been trained to measure a person’s fasting blood sugar, or the glucose levels present in your blood, at least eight hours after your last meal. Most don’t express concern until results show blood sugar levels reaching 110 mg/dl. That’s when they start “watching it.” Then, once your blood sugar reaches 126 mg/dl, your doctor will diagnose you with diabetes and put you on medication.

The important thing to note is that blood sugar is the last thing to increase…so for many people, a fasting glucose test detects diabetes too late. Long before your blood sugar rises, your insulin spikes. High insulin levels are the first sign that can precede type 2 diabetes by decades, Damage begins with even slight changes in insulin and blood sugar.

A two-hour glucose tolerance test can help detect high insulin levels. This test measures not only glucose but also insulin levels, yet doctors rarely order it. Instead, they usually don’t express concern until blood sugar is over 110 or worse, over 126, which is diabetes.

Many of my patients have normal blood sugar levels but very high insulin levels and other signs of pre-diabetes, yet when they come to see me they have not been diagnosed with pre-diabetes.

Even when they have a blood sugar level over 100 mg/dl and a two-hour glucose tolerance test result of over 140 mg/dl, 90 percent of patients who display these conditions have not been diagnosed. That’s because doctors don’t measure insulin.

Think about this. Insulin resistance contributes to most chronic disease in America, a country with world-renowned health care, yet 90 percent of people who have this condition have not been diagnosed. One test could change all that.

I recommend early testing for everyone:

  • Over age 50
  • With a family history of type 2 diabetes
  • With central abdominal weight gain or abnormal cholesterol
  • With any risk of insulin resistance (even children)

Ask your doctor for a 2-Hour Insulin Glucose Challenge Test. This should be done when fasting, with blood sugar and insulin levels checked at fasting, then again at one- and two-hour intervals.

Your blood sugar levels should be less than 80 mg/dl fasting and never rise above 110 or 120 mg/dl after one and two hour checks. Your insulin should be less than 5 mg/dl fasting and should never rise above 30 mg/dl after one and two hour checks.

If your results show high insulin, you need to eliminate the things that are sending your biology out of balance and include what’s needed to help your body rebalance itself. These eight interventions can become extraordinarily powerful to normalize insulin:

  1. Eat whole, fresh foods. Food is information that controls your gene expression, hormones, and metabolism. Choose low-glycemic real foods including fresh vegetables, fruits, legumes, non-gluten grains, nuts, seeds, and high-quality animal protein.
  2. Remove all sweeteners. Far from the free pass some people consider them, artificial sweeteners can raise insulin levels and contribute to insulin resistance. One study in the journal Diabetes Carefound sucralose (Splenda) could raise glucose and insulin levels. Give up sugar but also stevia, aspartame, sucralose, sugar alcohols like xylitol and malitol, and all of the other heavily used and marketed sweeteners unless you want to slow down your metabolism, gain weight, and increase insulin resistance. Many of us have lost touch with what constitutes “sweet,” and we have to retrain our taste buds to appreciate the natural sweetness of, say, natural vanilla or roasted almonds.
  3. Control inflammation. Dietary sugars of all kinds and refined vegetable oilsare the biggest contributors to inflammation. They increase insulin levels and turn on genes that lead to chronic inflammation, creating a downward spiral into more inflammation, poor blood sugar control, and chronic disease. Besides removing the offending foods, address food sensitivities and allergies to control inflammation. Incorporate plenty of anti-inflammatory foods including wild-caught fish, freshly ground flax seed, and fish oil.
  4. Increase fiber-rich foods. Whereas our Paleolithic ancestors got 50 – 100 grams of fiber a day, we now average less than 15 grams. Studies show high-fiber foods can be as effective as diabetes medications to lower blood sugar without the side effects. Fiber slows sugar absorption into the bloodstream from the gut. Eat a wide variety of fiber-rich plant-based foods including nuts, seeds, fruits, vegetables, and legumes.
  5. Get enough sleep. A study in The Journal of Clinical Endocrinology and Metabolism found in healthy subjects, even a partial night of poor sleep contributes to insulin resistance.  Make sleep a top priority to normalize insulin levels. Avoid eating three hours before bed and take an UltraBath to raise your body temperature and relax your muscles. Go to bed and wake up at consistent times, only use your bed for sleep and sex, and try herbal therapies or melatonin if necessary.
  6. Address nutrient deficiencies. A number of nutrients play a role in insulin management, including vitamin D, chromium, magnesium, and alpha lipoic acid. Deficiencies in any nutrient can stall your biochemical machinery, knocking your blood sugar levels out of balance and making you more insulin resistant.
  7. Incorporate the right exercise. Exercise might be the most powerful medicine to manage blood sugar levels and make your cells more insulin sensitive. When it comes to exercise, time becomes a huge hurdle for many people. That’s why I recommend high-intensity interval training (HIIT), also called burst training, which you can do in just minutes a day. A study in the Journal of Obesity found among its other benefits,burst training helped decrease fasting insulin and reduce insulin resistance. Combining burst training with weight resistance provides the most effective, efficient way to normalize blood sugar and insulin levels.
  8. Control stress levels. Chronic stress elevates cortisol, your main stress hormone. Increased cortisol levels elevate blood sugar and promote the accumulation of belly fat that I commonly see in patients with insulin resistance or diabetes. You can’t eliminate stress, but you can reduce its impact. Find what works for you. That might be meditation, yoga, deep breathing, or exercise.

If this seems like a lot, don’t worry. I’ve created a 10-Day Detox Diet Challenge that will help you address, step-by-step, each of these areas. This Challenge includes live coaching support from my nutrition team and me, community support and a complete toolkit. To learn more or to register, click here.

What other strategies would you add to control blood sugar, normalize insulin levels, and reduce your risk for obesity and chronic illness? I welcome you to share your thoughts here or on my Facebook fan page.

Wishing you health and happiness,
Mark Hyman, MD

Mark Hyman MD is the Medical Director at Cleveland Clinic’s Center for Functional Medicine, the Founder of The UltraWellness Center, and a ten-time #1 New York Times Bestselling author.

Comments (31)

  • Hi, Dr. Hyman!

    Speaking of #1 — whole fresh foods — what is your position on watermelon, generally? Few folks speak to watermelon specifically, and I’m always curious — very sweet, but with lots of water to lighten the glycemic load, so I’m never sure where it stands!

    If context matters, I eat a little more than a pound of watermelon — about 560 g — twice a day (summer only, of course). That’s 42g of carbs, with 34g sugar, and a glycemic load of 12 — however, I eat it slowly, over about 45 minutes (if I eat it fast, though, I get some muscle weakness/pain in my bicep area). I eat it on a mostly empty stomach (about an hour after a raw egg and then again about an hour or so after a smoothie of berries/banana/celery/greens).

    Thanks for your thoughts!


    • Hi Kelann,
      If your goal is effective blood sugar management, Dr. Hyman recommends limiting foods high in sugar such as watermelon. Did you know you can work with Dr. Hyman’s nutritionists virtually? For personalized nutrition coaching where you can receive 1:1 support with Registered Dietitians, please see:
      Wishing you the best of health,
      Dr. Hyman Staff

  • Shalom,


    All one needs is good clean water & a few drops of 3% Hydrogen Peroxide to give the seeds a kick start. After the first day just use the water on its own.

    When you buy vegetables & they have a root base or roots still on them, cut them off at the base & plant them again.

    To get people to start eating lots of veggies, use some curry sause with the chopped up veggies & an apple. Spoon it into glass jars & keep in the fridge.

    It works wonders!


    The Benefits of Rebound Exercise: 33 Ways the Body Responds

    1. Rebounding provides an increased G-force (gravitational load), which benefits the body by strengthening the musculoskeletal systems.
    2. Rebounding protects the joints from the chronic fatigue and impact delivered by exercising on hard surfaces.
    3. Rebounding helps manage body composition and improves muscle-to-fat ratio. Rebound Exercise benefits you by giving you more control over these.
    4. Rebounding benefits lymphatic circulation by stimulating the millions of one-way valves in the lymphatic system. This benefits the body’s immune capacity for fighting current disease, destroying cancer cells, eliminating antigens and preventing future illness.
    5. Rebounding circulates more oxygen to the tissues.
    6. Rebounding establishes a better equilibrium between the oxygen required by the tissues and the oxygen made available.
    7. Rebounding increases capacity for respiration.
    8. Rebounding tends to reduce the height to which the arterial pressures rise during exertion.
    9. Rebounding lessens the time during which blood pressure remains abnormal after severe activity.
    10. Rebounding assists in the rehabilitation of existing heart problems. Rebound Exercise also benefits recovery from heart procedures, providing gentle, low impact circulation.
    11. Rebounding increases the functional activity of the red bone marrow in the production of red blood cells.
    12. Rebounding gradually improves resting metabolic rate so that more calories are burned for hours after exercise. Related, Rebound Exercise benefits the post-exercise “Glycogen Replenishment” process.
    13. Rebounding causes core muscles and large muscle groups to contract, resulting in the rhythmic compression of the veins and arteries, which more effectively moves fluids, both blood and lymphatic, through the body and back to the heart, lowering peripheral blood pressure and lightening the heart’s load.
    14. Rebounding decreases the volume of blood pooling in the veins of the cardiovascular system preventing chronic edema.
    15. Rebounding encourages collateral circulation by increasing the capillary count in the muscles and decreasing the distance between the capillaries and the target cells.
    16. Rebounding strengthens the heart and other muscles in the body so that they work more efficiently.
    17. Rebounding gradually allows the resting heart to beat less often. Regular Rebound Exercise has been shown to benefit the heart rate, resulting in favorable decreases in resting heart rate.
    18. Rebounding lowers circulating cholesterol and triglyceride levels.
    19. Rebounding lowers low-density lipoprotein (bad) in the blood and increases high-density lipoprotein (good) holding off the incidence of coronary artery disease.
    20. Rebounding promotes tissue repair.
    21. Rebounding for longer than 20 minutes at a moderate intensity at least 3x per week increases the mitochondria count within the muscle cells, benefiting in total endurance. Perhaps you will easily skip those naps.
    22. Rebounding benefits the alkaline reserve of the body, which may be of significance in an emergency requiring prolonged effort.
    23. Rebounding improves coordination between the propreoceptors in the joints, the transmission of nerve impulses to and from the brain, transmission of nerve impulses and responsiveness of the muscle fibers.
    24. Rebounding improves the brain’s responsiveness to the vestibular apparatus within the inner ear, thus improving balance.
    25. Rebounding offers relief from neck and back pains, headaches, and other pain caused by lack of exercise. Rebound Exercise has been shown to benefit body alignment and posture.
    26. Rebounding enhances digestion and elimination processes.
    27. Rebounding allows for deeper and easier relaxation and sleep.
    28. Rebounding results in better mental performance, with keener learning processes.
    29. Rebounding curtails fatigue and menstrual discomfort for women.
    30. Rebounding minimizes the number of colds, allergies, digestive disturbances, and abdominal problems.
    31. Rebounding tends to slow down atrophy in the aging process.
    32. Rebounding is an effective modality by which the user gains a sense of control and an improved self image.
    33. Rebounding is enjoyable!

    People who rebound find they are able to work longer, sleep better, and feel less tense and nervous. The effect is not just psychological, because the action of bouncing up and down against gravity effectively stimulates the lymphatic system without trauma to the musculoskeletal system. This unique discovery is central to the reasons Rebounding has become one of the most beneficial forms of exercise ever developed.

    With a Rebounder in your bedroom, you can exercise 365 days of the year for 10 to 20 minutes a day!

      • Rebounding is jumping on mini-trampoline. I have one and have used it before, but seemed to have problems needing to urinate all the time while jumping. So I’d have to stop, then start again. You can buy the mini trampoline/rebounders on-line or possibly in sporting goods stores. They are small, and the legs detach for storage if needed.

        They truly are great!

    • Hello

      Thank you for that article. This is the first time I have heard of rebounding. You said it could fit in a room. What is a rebounder please? If one has blood clots is it safe to use and how often? Thank you.

  • I thought watermelon was high on the glycemic index but low on the glycemic load. In other words, watermelon delivers sugar quickly but the actual amount delivered is low. The indices I’ve checked seem to support this. Should this be interpreted differently?

    • Hi Iris,
      Yes, you are correct. Watermelon has a high glycemic index, but a low glycemic load for one serving. This means that you would need to eat a lot to cause a spike in blood glucose. Remember that everyone is different in how their body responds, so if you are working to optimize your blood sugar be sure to check your blood glucose after eating it.
      Wishing you the best of health,
      Dr. Hyman Staff

  • My husband has just been diagnosed with diabetes. He immediately cut out International coffees which he drank quite a bit, desserts, treats, etc. We are eating a lot of fruits and vegetables and have cut out bread, rice, pasta (for the most part…he is Italian and says he would like to enjoy that once in a while). What do you think of the Mediterranean Diet? If we are very careful about his diet can it be reversed? What is your advice for him?

    I would appreciate hearing from you. My husband’s name is Angelo Viggiano and we are both patients of Dr. Lee Copeland in Clovis, CA. He recommends you very highly!

    We will await an answer and appreciate that. Thank you!

    Sharon Viggiano
    [email protected]

    • Hi Sharon,
      Thank you for sharing your story and congratulations for making such great changes in your nutrition. I recommend that you discuss the Blood Sugar Solution Program with your doctor to work together to optimize your husband’s blood sugar. His nutrition and lifestyle can have an incredible impact on his health!
      Wishing you the best of health,
      Dr. Hyman Staff

  • I test every patient with a Hgb A1C and I am able to detect pre-diabetes in many patients with normal fasting blood sugars. How does this compare in terms of early detection to the 2 hr insulin glucose test?

    • I’m glad you asked as I was wondering the same thing. I also test many of my patients with the HgbA1C and typically have at least a good discussion with them regarding diet changes if it comes back in the pre diabetic range. Those who don’t seem terribly interested in changing their diet usually get started on medication.

  • Will you please correct this erroneous information. A 2 hour glucose tolerance test only measures glucose. If you want the information about the insulin levels and glucose levels you need an insulin response test. Basically the same test. Just measures both levels. I asked and received a 2 hour glucose tolerance test and was very disappointed to receive just the glucose readings. I went by information in an early part of your book “The Blood Sugar Solution.” Continued reading brought me the information about the insulin resistance test. I am disappointed that you are quoting the erroneous part of your book here,.

    • Faye, I’m afraid you might have asked for the wrong test. Dr. Hyman specifically says, “Ask your doctor for a 2-Hour Insulin Glucose Challenge Test”, at the beginning of this article. This is NOT the same thing as a 2 hour glucose tolerance test, as you said you had asked for.

  • Today I had an appointment with a dietician at our local hospital regarding my type 2 diabetes. We discussed carbs, and fats, and reading labels on food products. When she asked me what type of fats I use, I told her i was interested in using coconut oil..The dietician freaked out and said it was one of the worst fats out there to use.. Virgin and non virgin I was told it was a bad fat to use… My question is: Will all the newer research out in the market these days, and the research being done on it, is coconut oil good for diabetics or is it all marketing? I know topically it is wonderful for your skin and some ailments, but please, I need to know what to do regarding this Oil.. thanks Lorie

    • Hi Lorie,
      Determining if coconut oil is appropriate for you depends on your overall health and risk factors. Coconut oil is a saturated fat and many health practitioners caution against over-using it for those at risk for cardiovascular disease. Coconut oil does not contain any cholesterol and can be an excellent addition to a healthy diet. Remember that there is no single food that will promote health on its own!
      Wishing you the best of health,
      Dr. Hyman Staff

  • You know what? I have watched and listened to all this advice over and over again. I have always eaten healthy meals, am not a “sugary drink” drinker (I prefer ice water), watch my portions and only occasionally eat a small piece of pie or cake. I’m afraid I am a victim of my heredity. Even when I have strictly followed advice, it does not do any good–my BS level still runs between 150 and 200. As a result of all this advice, I walk around with a very black cloud hanging over my head all the time. There was one bright spot regarding this, when my ophthalmologist told me to keep my numbers below 200 and I should be fine. I’m sure someone is going to leap on that one!

    • Hey Pat, Hang in there. Give yourself credit for doing the right things. You’re aware of what’s going on and not in the dark about it.
      My husband had diabetes and all the food etc was re-evaluated.
      You may be able to tweek the food more. I’ve found that reading labels is key even when you’ve read them before, it can changed.
      Cooking from scratch helps a lot as you know what’s in there. Making a big batch then freezing helps especially if one is working and/ or has a very busy schedule.
      Or fine tuning as to what made the blood sugar good today.
      Maybe you can pin point the positives and build from that.
      Hope this helps but want to encourage you it can be challenging at times. Keep going you’ll get there.

      • Matthew,

        I live in Thailand but I know that Bitter Melon is the secret to the long-lived population of Okinawa, Japan. I sautéed it with onion, olive oil, garlic and chili peppers, I think it’s delicious but for some it’s just too bitter. You can take some of the bitterness out by soaking the bitter melon in water with salt and in the sunshine for one hour. I also make a tart and tasty juice with it using my juicier. It’s an amazing and exotic fruit, there are studies from U of Colorado showing pancreatic tumor shrinkage of 62% in 6 weeks with a equivalent human dose of 5 grams a day. ( study was done with mice.)

        Momordica sharantia is the scientific name. It is used to treat diabetes in Ayurvedic medicine. There are two varieties, one is larger called Chinese with a lighter green color and the other is a smaller dark green one, both with knotty ridges running the length of the fruit.

  • I’m a bit confused by the terminology on my recent glucose tolerance test results (which refer to “plasma”) vs. the fasting blood sugar results (which say “serum”). In both cases, the reference levels say that my results are normal, but when I compare numbers to the ones in this article, my numbers are high enough to put me in the pre-diabetes or at-risk range. Why are your ranges lower and how do I interpret plasma vs serum glucose results? Lastly, what is the difference between the insulin response test (that Faye refers to above) and the glucose tolerance test? Thanks!

  • I have chronic epstein barr virus. I have all the dr. latest books. But EBV is a herpes virus and nuts seem to have high levels of arginine. These cause herpes flares. Should I totally avoid this or not? I have no idea what to eat as a snack when I have no energy.

    • Hello Mimo,
      Thank you for your interest In Dr. Hyman’s work. Unfortunately he cannot provide you personalized medical advice in this forum. In order to provide you the proper care you need we hope you will seek the attention of a local qualified Functional Med practitioner soon. To locate a doctor near you who practices functional medicine like Dr. Hyman, go to and scroll down to where it says “locate a practitioner” and enter your location. Progress accordingly from there.

      You can also make an appointment to be a patient at Dr.Hyman’s UltraWellness Center in Lenox, MA. Please go to:
      Wishing you the best of health,
      Dr. Hyman Staff

  • Dr. Hyman and Staff. it all sounds good except: with the mercury, pcbs and now radiation in wild caught salmon and meats’ inextricable link to colon cancer, wouldn’t 42 grams in only one cup of high quality protein, free from dietary cholesterol, free from saturated fat, free from chemicals and containing nature’s magic phytonutrients and fiber, from organic black bean soup be the way to go?

  • Hi , I was just wondering since Dr Hyman mentions that all sweetner are even , Many studies involving Stevia are actually stating that stevia glycosides have a capacity to increase insulin sensitivity. We know that sweet taste receptor T1R3 on the tongue can actually increase Incretins effect like GLP-1 . If you actually check the graph with the article he cited for glycemic and insulin response you see that blood sugar actually drops down faster with Sucarlose preload . What are your thought on this ?

    • Hi Sasha,
      The hemoglobin A1C test can also provide useful information, but Dr. Hyman recommends asking your doctor for a 2-Hour Insulin Glucose Challenge Test. This should be done when fasting, with blood sugar and insulin levels checked at fasting, then again at one- and two-hour intervals. This will give you the whole picture about your blood sugar and insulin function.
      Wishing you the best of health,
      Dr. Hyman Staff

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