Dawn Phenomenon and Weight Gain correlation

During the summer I meticulously keep my weight between 125-127lbs. Going out to eat, BBQ’s etc. present a challenge on the one hand while better weather offers more opportunities for outdoor exercise.

My first indication that I have added a few .1lbs. or more is when I first wake up in the morning and take a peek at my CGM and notice that during the early morning hours, while asleep, my blood sugar has been climbing into the 90’s (Dawn Phenomenon) which is beyond my normal range. My normal morning BG is about 80. Sure enough, I get on the digital scale and weight has gone up. My CGM is my first indicator that I have been naughty and have consumed more calories and carbohydrates than my body can handle and if I don’t do something about this gluttony, my weight will continue to increase. I have 4 ways to deal with this:

  1. Take a little insulin which promptly brings my BG back down to normal, however that has just hidden the symptoms of my problem and additional weight gain does not go away, on the contrary weight continues to climb with this approach.
  2. Exercise for a few hours which is not always an option due to time, weather or motivation. Additionally, it takes a heck of a lot of exercise to burn off several hundred extra calories.
  3. Intermittent fasting (IF) which basically means skipping 1 or more meals a day. Breakfast is usually easy to skip, but the best meal to skip is dinner as those are the extra calories that tend to linger in the body all night while sleeping and just pile on extra weight. This takes more will power than exercise but gets much faster results.
  4. A combination of 2) and 3). This gets the quickest results but not the most pleasant experience.

For me there is a very direct correlation between dawn phenomenon and weight management. When I eat the proper amount of calories and carbohydrates to keep my weight stable, I do not ever get dawn phenomenon. I define dawn phenomenon as an early morning BG rise in excess of 10 points while asleep. There have been several posts about dawn phenomenon and several posts about weight management but I do not recall any posts that draw a correlation between the two so I thought it would be interesting to open this up for a discussion which may be of help to some diabetics.


No machine can accurately read BG within 10 points. They are simply not accurate to that level of precision. Did you mean to write 100 points?

If you are raising an unusual 100 points starting in the early morning (like, 3am), I would call that dawn phenomenon.

If your numbers are consistently higher, across the board, requiring increased basal, I would attribute that to weight gain. If that’s it, you may see some roller coaster-ing, or increase in system variability. Incorrect basal dosage will be more disruptive to the system and lead to more “chaos.”

If you need more short term insulin (correction or bolus), then I would attribute that to diet.

I’m glad you found the answer for you! I’d have to say though I wish it was that easy for me. Even when I was losing weight from eating very little for a few months my Dawn Phenomenon did not go away. My basal rate dropped some overall, but not my increased basal rate for those morning hours! My DP stayed and is still with me and I definitely am not gaining any weight.

Nope, I said 10 points and I mean 10 points on my Dexcom G5 CGM. Is it always 100% accurate, no but close enough. My Dexcom Clarity reports are currently showing 5.6% Glucose Management Indicator, 96 mg/dl, Standard deviation of 15 and 100% Time in range. My daytime Settings 6 AM to 10 PM are low 55 and high 150 and my night time settings are low 55 and high 130. My standard Insulin to carb raio is 1 Unit Humalog to 3 Carbs. 1:3.

You most likely can’t be accurate within 10 points but my belief is that is because your standard deviation is much higher than mine. My entire range to stay in control is within 95 points during the day and within 75 points at night, so for me a 100 point swing tells me I am totally out of control.

I had exactly the same thought. For me, dawn phenomenon is going up 200 points in the morning, not going up 10!

And yes, if I get up at 80, and feel very proud and satisfied of my overnight control, if I don’t eat anything I end up at 280 in an hour or two.

We are obviously all very different which is why I think it is important when we use general terms such as Dawn Phenomenon we technically define what that term means to each of us as individuals because as these posts show the huge definition variation can otherwise miss-lead or cause someone to have a totally different experience from that of the individual that posted.

It took me several months to achieve the control I was looking for as I am so Carbohydrate intolerant. Although my standard I:C ratio is 1:3, during certain times of day with certain Carbs it is down to 1:2. My DP went away when I went to eating LCHF, low carb high fat but I did not particularly enjoy that diet or believe that it would be sustainable long term. I keep varying my diet by adding more plant based vegetables, (no fruit as that puts my bg through the roof) but if I eat more than a modicum of plant based after lunch, my DP returns.

I limit my meals to 15 grams of Carbs and vary those carbs as much as possible. You may want to play around with the type of carbs you eat and at what time of day you eat them as a test. I saw that as part of fine tuning my approach but maybe it had more effect than I realized.

CJ114, from the standard deviation you are achieving, you are better controlled than the typical non-diabetic. In particular, your range on waking is slightly better than the non-diabetics in this CGM study: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2769652/

Yes, you are correct - That was my goal to get into the same range as a typical non-diabetic and it has taken me 29+ years to get there, although constantly fine tuning based on my CGM and digital scale, in the past few years is what drove it home for me. Until a couple of years ago, anybody that told me I could reach these results, I would have told them they are crazy. Modern technology, lots of trial and error, and high discipline brought it all together. I have had these results now for 4 months so the current challenge is how to keep these results and still have a life without obsessing about my diabetes.

BTW, the CGM study you refer to for non-diabetics was done with individuals eating 50 grams of carb meals 4 times a day. My BG would go through the roof on that diet. I am on 15 carb meals twice a day and when I need to lose a few .1lbs I skip a meal.

In general, your control will get better as you age.

I’m not explaining this in an understandable way. How do you test the accuracy of your Dexcom reading?

If you test it against a BG machine, and your Dex reads 100 and your machine reads 100, you still can’t say it is 100% accurate. The machine has 20% variability from your body’s true BG. So, maybe your real life BG is actually 80 to 120. Thats more important to be aware of if you test on a machine and you are 70.

I don’t use any machines. I test my Dexcom CGM twice a day at 8 AM and 8 PM against a finger stick read by a Contour next One meter supplied by Dexcom. For the past few decades I record all my finger stick results and since going on CGM I also record my 8 AM and 8 PM CGM readings. Except for a few outliers, my CGM and fingerstick are within 4%. I am careful not to test right after a shower or other times such as close to after meal times when there can be known variances between interstitial fluid and blood readings or if I don’t have a steady horizontal trend line for at least last 3 5 minute readings.

When I go to Joslin and the phlebotomist does a finger stick I ask her to squeeze out a blood drop large enough that can be used for both her test strip and mine so that I can then verify my Contour next One result to the result used by the lab equipment at Joslin. On my last visit they were identical and on the past they have never been off by more than 2 points, so within 2 1/2 % at worse case.

I do not experience 20% variability or anywhere near that based on any of my results. If on the other hand my meter, the Joslin equipment and the CGM are all out by 20%, as long as that 20% is in the same direction, it would not matter as we are really looking at deviations rather than absolute numbers.

There is, of course, always the backup check which is A1C to help validate the BG’s and Joslin always reports A1C very slightly higher (about .2%) than converting my BG numbers to A1C using a formula.

I know people on a low carb diet that have DP too, so it is not the answer for everyone. Although some people had success with it going away on low carb.

I don’t have any desire to go low carb except in the am when I am no food, so no carb lol!!! But after that I eat whatever I want and enjoy being able to do so. I am 6.4% A1C and have been for a while. I usually use 1 unit to 3 carbs if I do try to eat anything in the am. But by afternoon I am 1 unit to 6 carbs and then 1 unit by 8 carbs by evening, and sometimes that is too much. My average standard deviation is around 25-29. I am happy with all that!

I enjoy whatever foods I choose to eat, I am a vegan and love pineapples, tangerines, potatoes, whole grains etc. I am a type 1 , LADA. I am not insulin resistant except in the hours following my DP.

That’s great the control you’re achieving. I was never 96 BG before I had type 1. ( I had a meter for at least 10 years prior to my first fluctuations and my fasting was always 100-102) I wouldn’t consider 1 unit per 3 carbs bad, it is a pretty common number for a lot of diabetics. Whatever works and you figure out what that is, is good in my books.

Not only does it have to work, it needs to keep you happy as well. What I am doing now with low carb has worked beautifully for the past few months but I don’t see it as sustainable year after year. Who knows, time will tell but in the meantime even though I am thrilled with my results, I am constantly testing other options as I love diverse foods and am exposed to new foods as I expand operations in new countries.


Take it or leave it. If your getting that level of precision, than your due to receive some prizes for medical breakthroughs. You have discovered some of the most precise equipment in the world. Its gotta be stuff that no one else in the world has access too.

My weight has varied by over 100 pounds over the years and I’ve noticed no difference in DP, jus a difference in TDD. Dawn phenomenon always caused a rise of 100-200+ mg/dl regardless of whether I was at my ideal weight or obese. I also ate a low-carb diet for two years (30 g/day) and saw no change or reduction in DP. The only thing that changed my DP was taking metformin, which made it disappear, though I do have to make sure that I keep on top of hormones, otherwise I can easily experience a 200 mg/dl rise overnight when the previous week I’d had a flatline.


Or maybe I just got lucky and the equipment I got was like finding some flawless diamonds or maybe my body is the perfect specimen for the equipment I use. Who knows, I can only share the results and how I got those results in hopes of paying forward all the help I have received on this forum which is what ultimately led to the best results in my life. I just hope that everyone can eventually be as thrilled with their results as I am with mine thanks to all the posters on this forum.

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Fascinating - Thank you so much for your post. - Hope to see more posts like yours to determine if there is any validity to a possible correlation, at least for a certain group of diabetics or if in my case it is purely coincidental for another reason.

Or maybe we are really having a conversation about OCD. IDK. It doesn’t feel like a healthy diabetes conversation. It feels like illness. Could also be liver damage. Could be aging. But, it feels, fundamentally, like unhealthy relationship with numbers. I have a moral obligation to state this ONCE. Beyond that, its yours.

I had a fairly stable weight until I started gaining about 1.5-2 years ago. I’ve gained 15-20 pounds over the last 2 years. I have never had DP, and I do not currently have DP either. On the contrary, I tend to experience a downward trend in the early morning hours. If my basal dose is accurate enough to give me a flat line through most of the night, then I’m bound to drop around 4-7 am. It seems my basal needs are the lowest at that time of day. This has been true on Lantus, Tresiba, and on the pump.

I was using Tresiba (started 1.5 years ago), and now I’ve switch back to Lantus. I think the inflexibility of Tresiba resulted in my eating more to prevent lows. Adjustments to my basal took at least 24 hours to show, so i think I ended up having more carbs to ensure I wouldn’t drop low when basal need changes occurred (which happen at least monthly for me as a woman). I think changes to my Tresiba dose took much longer to show for me than for other people using Tresiba.

Hopefully switching back to Lantus will help me. We’ll see. I already eat fairly healthily and exercise regularly.