How Circadian Rhythms Affect Blood Sugar Levels

Author Since: Mar 11, 2019

  1. I know this might be a dumb question, but what if I work grave shift? Does my body, food clock, adapted to my new sleep schedule? Could "my" 8pm become my 8am?

  2. If I eat high glycemic food in the morning, I become super sleepy. If, on the other hand, I do it in the evening, I don’t feel any impact whatsoever.

  3. The piece about an 11pm meal influencing post breakfast blood sugar the next day is interesting. Whenever I have a midnight snack I usually justify it by thinking I’ll just eat better the next day.

  4. Eat breakfast around 7:30, lunch around 11:30 and fresh fruit/veggies for dinner around 4:00.
    Not only feeling more energetic, I’ve lost 8 lbs in 4weeks, almost 2 inches around my waist.
    Thank you Dr. Greger!

  5. Thank you Dr Greger. I cannot tell you how thankful I am for all your hard work. I am continually on a healthy quest and value so much all your expertise and information.

  6. Funny you're doing this series while I'm having this exact issue! I have a 10pm snack, usually air popped popcorn and rice cakes. Nothing heavy. About an hour or 2 later I feel like I've entered the death realm and can't sleep. I had prediabetes before going WFPB.

  7. But in nature we would not eat instantly after we wake up right, because it would take time to find food? Not disagreeing with the science, i just wonder why it is like this.

  8. Love you Dr Greger, but in a time of scarcity, the best strategy for the body is to save glucose for later in time for need. Our bodies are better prepared for scarcity than excess food

  9. Dear Michael, I hope that you feel very fine. How do you feel besides my hopes? 🙂 Is it possible that it can be used as an advantage to have breakfeast in the evening after a daily-fast and reach an adequate (not too-high, nor too-low) sugar spike with less food? Could that empower one to be more auto-sufficient with less amounts of eaten calories?

  10. Damn… this is some VERY INTERESTING INFO!!! I've never really been a breakfast eating person before… I was never "hungry"… I would try to "fast" into lunch time but then that would make me hungrier, eat a bigger and later dinner and feel REALLY TIRED and Sluggish even into the next morning… been trying this just accidentally since I've heard McGregor mention it recently and ive been feeling much better even with my tooth extraction and discomfort associated with that. I can't wait to see my results as I continue this journey!!! Thank you so much for sharing this info!

  11. This is such a fascinating video!! Thank you so much for this awesome and interesting video. Your videos always inspire me to keep posting on my channel!

  12. I've been skipping "dinner" most days of the week for a while now. I consume all of my calories everyday in 2 – 3 meals, just in the morning and afternoon. During the day I'm busy and I workout and walk and in the evening I relax, read and go to sleep early. I feel so amazing and this way of eating helps me to maintain my weight nicely. I like going to sleep on an empty stomach – I'm not hungry or starving however. Thank you for posting!

  13. Watching at 9:30am eating for my second time today. I naturally want to eat a ton of food between 6am-3pm after that my body is usually not hungry no matter how much I want to be.

  14. Can someone fill me in on the ideal time for dinner? It gets dark here in Ohio around 5:00pm right now so would I need to be eating near that time?

  15. Is there any literature that suggests that certain people genetically have maybe…. delayed clocks? Or that you can train your clock to start its food related cycle later?

    I have been skipping breakfast since I was a kid. Even on the weekends, I rarely ate before maybe 11 or 12. Hearing about this research recently has made me want to push myself to eat breakfast in an attempt to reduce my calorie density later in the day, or maybe prevent me from later snacking/meals. But when I do try to eat at a time a few hours earlier, often before I am hungry, it gives me a stomach ache or I literally have trouble eating because the food is so unappetizing to me at that time.

    Is it crazy to think that I have trained my clock to start later? Or I am genetically predisposed? I can easily go the first 4 or 5 hours in the day without feeling hungry. I'm sure I could train it back, but it would kind of mess with my routine in a way that I would find very hard to change. So am I deluding myself? Or is it very feasible that I am different in that way?

  16. Back with the next installment of the chronobiology series! For all of the videos so far, check out the playlist: There are more to come. -NF Team

  17. Ever since I had a freak high Hba1c last summer after being kept off my bike by post-viral fatigue, I eat my simplest carbs for breakfast, something reassuringly stodgy for lunch, and dinner is non-starchy veggies and beans.
    And yes, I will sometimes skip dinner when I'm not working, or cycling.
    I got somewhat annoyed by the "diabetes" misdiagnosis and feel the term should be reserved for a compromised pancreas rather than insulin resistance due to an over-stuffed liver.

  18. But if you eat refined grains in the evening, your blood sugar will drop excessively after a while thus putting you to sleep. Well, this is very much dependent on the individual. People with diabetes already may not react this way.

  19. So interesting. My conclusion, after all the research you, dr. Satchin Panda en dr. Rhonda Patrick showed: do Time Restricted Eating early in the day. Especially if you have difficulty losing weight or controlling blood sugars. I personally don’t do it, but try to stop eating after 7 pm.

  20. So if your circadian rhythm is way off, fasting until morning is not good? Meaning waking up in the late PM, awake all night, unable to sleep.

  21. Perhaps you could bump up your narration at least as loud as your new theme audio. It's important information and important that we can actually hear your dialogue on any device we might be using. As usual, thank you and blessings.

  22. Thank you! Seems my penchant of skipping breakfast, or having just a cuppa, fruit with nuts, may explain my persistently high LDL. I keep my sat fat, (from nuts, seeds and beans), on average around 5 grams a day(Cronometer). Yet my last fadting LDL was102. 😕 Shocking quite frankly, given what I eat.

    I've been trying to eat more at breakfast, nothing past 4pm, but some days I get busy and fail. I will renew my efforts, thanks to this information! 🌱

  23. This is a revelation for me. I work in a kitchen and leave work at midnight. I usually eat when I get home (not many vegan options at work). I have been struggling with weight loss for years, even after going heavily whole food plant based. I am going to try adjusting my eating schedule now! Thanks Doc!

  24. Why is it that veganism and atheism seem to go hand-in-hand. Here we have a Godless Dr. promoting evolution & telling you how to live longer via veganism. This is because for atheist aka the godless ..there is no eternal life. The Creator Of all things has set before you life and death, choose life so that you may live eternally via his son Jesus Christ

  25. Come on man. You got videos about skipping breakfast and now skipping dinner? Ive never met people who have perfect sleep patterns and can live without eating. We are only allowed lunch? Then your tired at work from eating to much… It just looks shady using corn syrup anyways as a test. Id assume the lower spike in the morning is due to your cells needing energy from the break of sleeping. Where at night you havent been in a deficit of fluid/food so now sugar is spiking in the evening because it hasnt been used up. Most people do not do muscular tiring physical activity even when work.

  26. As everything as a reason in nature and our body, what would be the reason for the body to elevate blood sugar in the evening? As someone an idea? 🤔

  27. Hi I'm a t2 diabetic managing it without drugs and a vegan diet. in my case time of day has a massive effect but the times are different to this study. Breakfast is the worst, improving all day then between 4 and 6 pm is OK before it starts to get worse again.

  28. do these results follow the 24 hour cycle set by the sun, or are they more about your sleep cycle (e. g. if you are a night owl)

  29. That study was on obese women with bad heart numbers. That doesn’t mean that non obese people with good heart lab numbers will have the same result. Come on Dr Greger when are you going to stop the far people videos and produce videos that inform ALL of us of good dietary measures?

  30. Wow I love all of Dr. Greger's videos but this is mind blowing information. I am fighting type 2 and have been eating plant based for 6 months and have dropped 80 of the 180 pounds I need to lose. But my blood sugar is still in the pre diabetic range. I am most definitely making breakfast my main meal and quit eating late in the day!

  31. I did an at home glucose test about a year ago. Age 49 at the time, eat about 700 grams of carbs/day. I did the test around 3pm and half an hour after downing .5 cups of Maple Syrup it reached 145. 30 minutes after that it was 129. 82 the next morning.
    The gory details if you want to see it:

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  33. wow i couldn't believe it… ! i always skip breakfast and eat dinner for more than 6 years now… and i thought that was the best time to eat… and now i think i need to change it… thanks doc !

  34. I've been thinking for a while about eating only when the sun is up. But after seeing this video, I will definitely do it.

  35. I paused at each graph/table and looked in more detail.

    This is totally mind-blowing. I am totally woke now, to this issue.

  36. "safer to skip dinner rather than breakfast" – I'd emphasize getting rid of high calorie foods in your dinner. Dinner is still an excellent time to squeeze in those dark green leafy vegetables and I've seen no argument that there's anything wrong with eating those late on the day.

  37. So I eat first meal at around 2pm, sometimes even 4pm, depending on my schedule. Dinner usually not before 10pm to midnight. So 2 big meals a day. I see absolutely no reason to change anything. It fits great into my schedule and convenience. And I feel great.

  38. i couldn’t understand a thing, it’s like he’s swallowing his words, with breathing intake problems. his words are not synchronised with his words. hard to concentrate

  39. Ok, I'm sold.. The past few videos have really convinced me that I should stop eating at an earlier time. Now I'm going to try to make the meals bigger in the AM and smaller at night

  40. This is good information to have for the next time a blood test is scheduled~~in the past I have eaten a lot at night on the day before blood tests because I know I will have to fast the next day. Probably influenced my test results in some kind of way.

  41. I never eat breakfast because I work overnight (I am asleep during breakfast). I had to work very hard to control my diabetes and get my body used to my new rhythm.

  42. I have type 1 diabetes and the amount of insulin I need to inject for a given amount of carbs is much higher in the morning compared to evening, and this is pretty common for T1Ds. My background insulin needs are also much higher in the morning. So how does that fit with circadian increased glucose tolerance in the morning? Are “normal” people just primed to release more insulin in the morning, and so increasing their glucose tolerance?