How Sleep and Holiday Dinner Affect Glucose

After it felt like I was starting to understand what was impacting my glucose readings, this past week threw me for a loop. After some technical difficulties applying a new continuous glucose monitor (CGM), that cost me a week of data, I finally got a new one on and connected in time for Christmas dinner on Monday December 25th.

Christmas Dinner

Christmas is a big deal for my girlfriend and I. In my life I’ve never had Christmas without family, and my girlfriend only ever had Christmas without her family once. We’re used to big home cooked meals with our parents and siblings. But at the end of October we moved a 3 days drive away to Colorado, and we weren’t returning home for the holidays. So we needed to figure out Christmas dinner on our own. And after an expensive and mediocre experience ordering out for Thanksgiving, we really wanted to make Christmas special.

So we cooked a meal mostly inspired by food my girlfriend is used to, which luckily for me meant she did most of the cooking. A turkey was too much meat for just the two of us, plus we didn’t have the necessary equipment to cook one, so we opted instead to make a whole chicken in the crock pot. My girlfriend also made two of her favorite dishes, pineapple bake (bread, crushed pineapple, butter and cream), a sweet and savory dish akin to a bread pudding, and green bean casserole. Plus garlic mashed potatoes, and roasted carrots, parsnips and cauliflower for balance. And cookies for dessert.

We ate an early dinner at 4 pm.

As discussed in a previous post I made sure that morning to eat a low carb, high protein and fat meal of baked wild salmon, roasted brussels sprouts and sautéed bell peppers, avocado and finished with olive oil, to try and limit the damage. I also followed up Christmas dinner with a salad of tomato, raw red onion, blueberry, avocado, apple and chicken.

I was surprised to see that within 30 minutes of dinner, despite a plate loaded with simple carbohydrates, my glucose only spiked 37 points. And within an hour it had returned to baseline. I was conscious during dinner to consume my chicken, green bean casserole and vegetables (protein, fat and fiber) before the mashed potatoes and pineapple bake, a tactic recommended by Levels that slows the absorption of glucose into your bloodstream, but I was still pleasantly surprised with the result.

But even more surprising were the days to come. And for the wrong reasons.

The remainder of my week remained mostly steady, although on Tuesday following Christmas I did experience two 30+ point spikes. But neither one of these seemed out of line. The first one was caused by two bowls of berries that I ate after a prolonged period that day of not eating. The second was a plate of leftovers. In both cases it also made sense to me because the day before I had gone off my normal eating habits with Christmas dinner, and I assumed by body was working to get back to baseline.

The most surprising of data came the following Sunday, New Years Eve, and continued through Tuesday. For New Years Eve we stayed in and cooked. This time we made venison meatloaf, the same garlic mashed potatoes and boiled broccoli. On the surface it seemed like a balanced meal, and in comparison to Christmas I had about half the amount of carbohydrates on my plate.

But within 45 minutes of eating my glucose spiked 58 points and remained elevated for 2 hours (compared to only 1 hour for all the previous spikes discussed in this post). On Monday I experienced two spikes lasting a total of 4 hours. The first spurred by green lentils, which had never had this affect before, and the second from 2 handfuls (not bowls this time) of blueberries. And on Tuesday lentils again caused a spike, this time 56 points. None of it made sense.

If Christmas dinner, which was certainly richer in carbohydrates, only caused a 37 point spike, then why was this meal and subsequent healthier carb meals causing these swings. I started to wonder what else might be at play, and I started looking into possible causes other than the quality and quantity of carbohydrates.

The first thing that occurred to was that the meatloaf contained added brown sugar and breadcrumbs, plus simple carbohydrates and sugar from the homemade sauce on top. But I only ate 1/4 of the meatloaf, so I doubted that could’ve caused such a surge. The other metric that made me doubt this was the cause was my average glucose was steady at about 10 points higher than normal. Something else was going on.

I was beginning to think it was sleep related. So searched and found this study, the Impact of Insufficient Sleep on Glucose, which was summarized on the Levels Health blog.

In short, sleep efficiency, duration of sleep, and the time you go to bed and wake up each day, all play a role in your glucose levels and in your ability to control glucose the next day. Maintaining an early bedtime, getting uninterrupted sleep and sticking to a regular sleep pattern have all been shown to lower glucose levels and improve glycemic control.

My habits over the prior few days had all been in direct opposition to that advice.

In the nights leading up to these spikes, my sleeping habits had been off. I hadn’t been getting less sleep than usual. About 5 hours per night, down from 6 - 7. I also had been going to bed closer to midnight as opposed to my 10 o’clock routine, and waking up earlier, between 4 - 5 am instead of between 6 - 7 am. My lack of consistency, duration, and sleep quality were now showing up in my elevated and volatile glucose levels.

I wasn’t happy, but I also wasn’t surprised. Sleep has become a key component of longevity and health span for this very reason. It greatly impacts your metabolic health.

Since I had anticipated that lack of sleep might be impacting me, Monday night I went to bed closer to 10 pm, and followed that up again last night. I’ve continued to wake up at 4:30 am, but I’ve felt rested. So far today my glucose has remained steady, but my avg glucose remains elevated around 100 mg/dL. Heeding the advice of the study, I also ate a low carb breakfast of chicken, brussels and peppers, and a couple of handfuls of blueberries for dessert.

But I’m confident sleep and stress are my issue and I’m going to continue to pay attention to both of those over the next week, while also staying away from garlic mashed potatoes and other simple carbs.

Early Glucose Monitor Results

On Wednesday of this week I started wearing a continuous glucose monitor (CGM) for the first time in my life. More than a year ago I started to toy with the idea of wearing one for experimental purposes. I wanted to see how different foods might affect me, and I also wanted to see what (if any) behaviors I would change as a result.

But I kept putting it off until I read this article by Peter Attia, M.D. advocating for wearing one to take better control of your health. So I ordered one from Levels, a company I’ve been following for over a year. As far I can tell, they’ve been one of the pioneers in the space of at home CGMs.

The package of 3 CGMs came about a week after I placed my order. They came in a nice box, with alcohol swabs to clean your arm before applying the CGM, as well as Levels branded stickers to go over the CGM and hold it in place.

My experience got off to a rough start. I applied the CGM to the wrong spot on the back of my arm (right on my tricep). Based on the instructions it’s where I thought it was supposed to go, but I immediately experienced pain and discomfort. I thought the pain would go away. But after nearly 3 days I decided to remove it and put on the second one.

This time I applied it correctly, placing in on the outer part of my arm in the space between my shoulder muscle and tricep muscle (pictured here). Now I forget it’s even there.

After the initial mess up, I’ve been amazed to see what foods impact me the most. The two most surprising, on opposite ends of the spectrum, are purple sweet potato and lentils.

Eating 1/2 of a purple sweet potato mixed with 1 tbsp of ghee, with 1/4 pound of ground beef, brussel sprouts, walnuts and pumpkin seeds, spiked my glucose 52 points.

On the contrary, a 1/2 a cup of cooked lentils, 2 chicken thighs, onion, olive oil, salt and peppers, actually lowered my glucose levels by 10 points before it rebounded (the 30 point spike is from a sauna session, which is expected).

So what gives? Because 1/2 a purple sweet potato actually contains less carbs (17 grams) than 1/2 a cup of cooked lentils (20 grams). The difference, is in their protein and fiber.

A 1/2 a purple sweet potato contains 1.5 grams of fiber and 2 grams of protein, while a 1/2 a cup of cooked lentils contains 8 grams of fiber and 9 grams of protein.

All that fiber and protein in the lentils is helping for your body to absorb the carbs slowly. The ratio of 8 grams of fiber to 20 grams of carbs is actually 2x the ratio you want (a minimum 1 to 4 ratio is the target).

1/2 Sweet Potato 1/2 Cup Lentils

Carbohydrates 17 grams 20 grams

Fiber 1.5 grams 8 grams

Fiber/Carbs Ratio 1/8 2/5

Protein 2 grams 9 grams

What’s scared me is after eating each of these meals, I felt the same. I didn’t feel like anything was going on inside of me that potentially was harmful. They both felt like balanced meals. But obviously I was wrong.

The next time I eat sweet potato (because I will continue to have it), I’m going to make sure I add enough fiber, protein and healthy fat to offset the sweet potatoes nutrient deficiencies.

I can’t wait to see what else I learn.