By Virginia Gurley, MD, MPH
MB (Marc Braman, MD, MPH):
So this session, we’re talking about diabetes and owls and larks. Welcome back, Dr. Gurley.
VG (Virginia Gurley, MD, MPH):
Thank you, Dr. Braman.
MB:
So in one of our previous sessions, we talked about people who prefer to stay up late at night and potentially sleep in in the morning, we gave them the label of owls, and people who prefer to wake up and get to bed early, sometimes calling them larks. What does being an owl or a lark have to do with your typical diabetes, your adult-onset type 2 diabetes?
VG:
Well, what several studies have found is that being an owl really increases the risk for developing adult-onset or type 2 diabetes. And in some studies, the risk is as high as two and a half times increased risk for diabetes. And in people who have diabetes already, adult diabetes, also being late to go to bed, being an owl, seems to make managing blood sugars a lot harder, too.
MB:
Wow, two and a half times. That’s a big increase. Why would being a night owl increase your risk for adult diabetes or make diabetes worse?
VG:
Well, it’s not fully understood. It seems like there are a number of different factors, but one is that going to bed late changes how your body handles fat. And another factor is owls are much more likely to skip breakfast. And in people with diabetes, skipping breakfast goes along with the marker for long-term blood sugar control, called hemoglobin A1c, being about 11% higher than people with type 2 diabetes who don’t skip breakfast.
MB:
So an 11% difference, that’s not insignificant. That’s in the same ballpark as many diabetes medications.
VG:
That’s right. Here’s another surprising finding from a study on skipping breakfast in diabetes: People with diabetes who don’t skip breakfast were able to eat 30% more calories and yet their body mass index, which is the ratio of their weight to height, it was 15% lower, which is 15% better.
MB:
So that sounds like a pretty good deal. I get to eat more and weigh less.
VG:
Yep.
MB:
Any ideas why this may be working like this?
VG:
Well, what they found is that breakfast skippers eat over half of their daily calories at dinner. So they’re making up for not eating any breakfast by eating a really big dinner. And what maybe is happening is that they’re setting up a vicious or harmful cycle where because they’re skipping breakfast, that makes them eat a larger dinner. And as we’ve talked about in another sessions, a large dinner makes you more likely to stay up late, which makes it harder to wake up in the morning, and then that makes you more likely to skip breakfast either because you’re not hungry from your big dinner, or because you don’t have time, or both.
MB:
So the good news here is that there’s a lot that we can do about this. And this sounds very much like what I’ve been telling my patients for years, “Your metabolism is just like a fireplace; you want to put the wood or the fuel in when you’re going to want it to burn. In the case of us as people, you put the food fuel in in the early part of the day, and then you leave very little in at night so you’re not burning the metabolism during the night.” So from the study that we’ve been talking about, there’s three specific things that we can do: To bed earlier. Smaller dinner, maybe even not any for some people if they choose to do that, and definitely eating breakfast. And we may be able, based on this research, even to knock off one or more diabetes medications if we do these very simple things. Thank you so much, Dr. Gurley.
VG:
Thank you, Dr. Braman.
Breakfast Skipping is Positively Associated With Incidence of Type 2 Diabetes Mellitus: Evidence From the Aichi Workers’ Cohort Study. Uemura M, Yatsuya H, Hilawe EH, Li Y, Wang C, Chiang C, Otsuka R, Toyoshima H, Tamakoshi K, Aoyama A. J Epidemiol. 2015;25(5):351-8. doi: 10.2188/jea.JE20140109.
Sleep Optimization and Diabetes Control: A Review of the Literature. Arora T, Taheri S. Diabetes Ther. 2015 Dec;6(4):425-468.
The relationship between breakfast skipping, chronotype, and glycemic control in type 2 diabetes. Reutrakul S, Hood MM, Crowley SJ, Morgan MK, Teodori M, Knutson KL. Chronobiol Int. 2014 Feb;31(1):64-71. doi: 10.3109/07420528.2013.821614.
