BS spike in the morning

Hi - my fasting Bs in the morning fluctuates between 140-170… My metformin dose is 1500 mg / day. exercise 4 times a week and carb intake is under control. during the day the numbers are in the 150-160 range. how do I control the morning spike?

Skip dinner 1 day and see what your morning fasting looks like. If you show significant improvement, then reducing your dinner carb intake could be the answer.


Try eating dinner earlier or try a very low carb dinner to see if that helps any. A lot of people have dawn effect or “feet on the floor” BG rise in the morning. You can also try taking your Metformin dose closer to bedtime as that might also help.

1 Like

Here is what may be happening.skipping supper sounds silly to me.

The dawn phenomenon, also called the dawn effect, is the term used to describe an abnormal early-morning increase in blood sugar (glucose) — usually between 2 a.m. and 8 a.m. — in people with diabetes.

Some researchers believe the natural overnight release of the so-called counter-regulatory hormones — including growth hormone, cortisol, glucagon and epinephrine — increases insulin resistance, causing blood sugar to rise. High morning blood sugar may also be caused by insufficient insulin the night before, insufficient anti-diabetic medication dosages or carbohydrate snack consumption at bedtime.

If you have persistently elevated blood sugar in the morning, checking your blood sugar once during the night — around 2 a.m. or 3 a.m. — for several nights in a row will help you and your doctor determine if you have the dawn phenomenon or if there’s another reason for an elevated morning blood sugar reading.

What you can do

Your doctor may recommend a number of options to help you prevent or correct high blood sugar levels in the morning:

  • Avoid carbohydrates at bedtime.
  • Adjust your dose of medication or insulin.
  • Switch to a different medication.
  • Change the time when you take your medication or insulin from dinnertime to bedtime.
  • Use an insulin pump to administer extra insulin during early-morning hours.
    This is from the Mayo Clinic.
    Hope it helps. Nancy50

As someone who does have dawn phenomenon, I have a salad (<15g carbs) or a protein with mashed cauliflower (<25g carbs) no later to 1830 hrs for dinner. The later I eat, the higher the bg. The more processed the food, the higher the bg. The higher the carb value above 30g, the higher the am bg. I also have to be especially aware of a bg/hormonal spike late am, even if my bg has been stable with a shallow increase overnight.


EL_Ver: What about lunch? White bread, pasta, rice etc. are lingering carbs that I can measure in my blood for up to 3 days, so not only do I restrict dinner carbs to very few in the 1-4 range but then also make sure that lingering carbs from previous meals do not continue to increase blood sugar all through the night, especially after 4 AM. I used to have really bad dawn phenomenon but totally cured it by analyzing types of carbs and carb intake from lunch through dinner. You appear to have done your testing on your dinner plan, so you may want to back up one more meal to run similar tests on your lunches.

I actually don’t eat any simple carbs anymore unless I am out with friends, then I might indulge in a small (half tennis ball) sized portion of rice. Pasta, bread a such are no longer part of my pantry. My Dawn Effect is seriously improved by my diet, exercise, and attention to proactive bg control. I sleep better at night and have fewer and less serious am spikes