Brief Recap of the First CGM Experiment
Wearing a continuous glucose monitor (CGM) without diabetes taught me that the fundamentals matter more than any single food or meal. Balanced meals with protein and fiber, eating regularly, and light movement after eating kept my glucose stable and my energy steady.
At the end of my 2-week experiment, my next question emerged:
What happens if I remove my evening or bedtime snack?
Will it help me have a stronger appetite in the morning and motivate me to eat sooner, before coffee?
Will it help my overnight blood sugar levels stay more stable (after simple carbs like French fries or potato chips, my blood sugar stayed elevated)?
For weeks 3 and 4, I decided to test a common piece of advice: reducing evening snacking.
The Change I Made: Reducing Evening Snacking
I chose evening snacking as my variable to change for a few reasons. One, it’s a common recommendation for glucose control. Fewer snacks at night leads to more stable glucose levels for most people. Additionally, I thought it might help me have an appetite for breakfast. This experiment was about glucose stability and energy, not calorie reduction or weight loss.
Looking back, I can’t remember a time in my life when I didn’t have an evening snack before bed. I used to run at the collegiate level, which required lots of extra energy for morning runs; I worked evening jobs that prevented me from eating much between 12 and 7 pm; or I was pregnant and/or nursing for a total of 6 years.
For me, reduced evening snacking looked like:
- Eating a balanced dinner with protein, high-fiber carbohydrates, fruit, vegetables, and water. Possibly a small square of dark chocolate right after dinner.
- Simply removing the usual evening snack that often happens after working for a few hours in the evening.
- Eliminating French fries, potato chips, or gourmet, sweet popcorn snacks.
- If I didn’t have time to eat enough for some reason, I did eat something later in the evening (dinner or a balanced snack).
Some things I didn’t plan on:
- We had earlier dinners planned on multiple nights per week due to after-school activities and routines. Sometimes they were as early as 4:30-5 pm, and then my kids might have a snack before bedtime. I may not have had a snack on some of those days.
- I planned to walk many of those mornings.
- Stress from annual kidney and body scans to confirm cancer-free status (I had renal cell carcinoma in April 2022 with a partial right nephrectomy).
In summary, I felt this change would be small and realistic, resulting in positive outcomes. No extreme restriction.
What Started to Go Wrong: Migraines Appear
I had taken the CGM off for a few days’ break between the first 2-week experiment and the start of the second 2 weeks. During this time, I had already started removing the evening snacks.
One thing I hadn’t planned on was migraines that were multiple days in a row and more persistent than usual.
I have a history of migraines, especially pre-hysterectomy, when my endometriosis was out of control. I do think hormonal levels (and stress) played a role in my migraines on top of hypoglycemia, but they are harder to track now.
Presently, my migraines are often related to:
- Poor sleep (ruled out, I was sleeping well and going to bed at the right time)
- Illness (ruled out)
- Dehydration (addressed and no resolution of migraines
- Inadequate eating (mostly balanced, just the elimination of most of my evening snacks)
I noticed one day that my migraine was so bad and not improving with normal treatment: electrolyte replacement drinks in case I was dehydrated, consistent meals with protein and fiber, and migraine meds. I then tried a glass of grape juice (simple carbohydrate), and for the first time, my headache improved somewhat. I sipped on grape juice that evening, and it helped.
The next day, the migraine was back, and I got desperate and was so sick of feeling unable to function. So, I ate a large French fry and a medium Dr. Pepper (a LOT of simple carbohydrates), and it mostly resolved. This made me feel like my blood glucose and migraines were connected.
So, I put a CGM sensor back on to see what was happening with my blood glucose levels.
The CGM Clue I Almost Missed: Blood Glucose in the 50s
After tracking my glucose levels with the CGM, I started to see my blood glucose repeatedly drop into the 50s, especially overnight or early in the morning. I would often wake between 2 and 4 am with the start of a migraine.
For many people, hypoglycemia is defined as a blood sugar of 70 mg/dL with symptoms including:
- Headaches or migraines
- Shakiness
- Fatigue
- Sweating
- Hunger or nausea
- Irritability or anxiety
- Difficulty concentrating
Interestingly, many of my migraine symptoms overlapped with hypoglycemia symptoms. The CGM alerted me to a drop in blood sugar, but the app didn’t pick it up below 70mg/dL. I had to log in online to view that data, which revealed many blood sugar readings in the 50-60mg/dL range and a few in the upper 40s. Yikes, I knew this was low! The screenshot below shows me putting a new CGM sensor on, and it kept reading 70mg/dL despite eating several times during this morning window.
I felt validated by my choice to drink juice and other simple carbohydrates to quickly raise my glucose levels. However, it’s important to follow the simple carbohydrate with a high-protein, fiber-rich carbohydrate snack or meal to maintain steady glucose levels.
Otherwise, you will end up in a continuous cycle of rising and falling blood glucose levels, requiring a quick-absorbing carbohydrate to get it back in range.
Once I stabilized my glucose in the 90 to 100mg/dL range with simple carbs, followed by a high-protein, fiber-rich carbohydrate meal or snack routine, my migraines started to improve over several days. I decided to end the “no evening snack plan.” And I stopped waking up with migraines.
Short story, every person is unique, has different energy needs, and eating and lifestyle routines that help them feel and perform their best. No one way works for everyone. Nutrition is highly individualized, and multiple successful eating methods can work to achieve overall health.
For example, my husband performs better with longer fasting periods and a shorter eating window (14 to 16 hours fasting with an 8 to 10-hour eating window).
I obviously do not! I struggle to get enough nutrients into my body in a short time period. I need more hours in the day to meet my nutritional needs and have adequate energy. I also have larger swings in my blood glucose that exacerbate headaches and migraines. (We’ve also learned one of our kiddos is a carbon copy of me…so I watch him carefully for low blood glucose levels, headaches, and irritability).
Blanket nutrition recommendations can have flaws. My husband and I are different people with different health conditions and daytime routines. Perhaps we could both adjust to different eating styles over time with careful planning, but sticking to what works best for each of us is realistic for now.
Why Evening Snacks Matter More Than We Think
So, let’s dive into what was happening. Due to my lack of evening snacks most nights of the week, I entered into a longer overnight fasting window than I typically would.
When your body no longer has a glucose supply from food (i.e., during the day when you are eating), the body switches to using glucose stored in the liver and muscles. With a “longer fast,” I was likely decreasing my liver glycogen faster than normal. During the day, eating adequate carbohydrates helps to build up liver glycogen stores.
My guess is that I wasn’t eating enough carbohydrates for storage, and then I cut a carbohydrate snack before bed. And some evenings we ate dinner earlier, further increasing my fasting window. Double or triple depletion for me.
On top of this, I was increasing my glucose needs with morning physical activity, further depleting my stores and circulating blood glucose.
Another factor I hadn’t considered until researching further was that hormonal changes during perimenopause/menopause (me with only one ovary since my hysterectomy in June 2022, a hysterectomy to help resolve adenomyosis and stage 4 endometriosis) lead to lower estrogen levels, which can alter glucose metabolism and reduce metabolic flexibility (the ability to switch between fuel sources). Estrogen helps your body better and more efficiently handle glucose and handle changes in diet or macronutrient composition.
Stress hormones can also increase glucose variability (large fluctuations between high and low blood glucose levels). Stress hormones may also make it harder for your body to regulate blood sugar levels.
It turns out I didn’t choose the best time to remove evening snacks. But I learned much about how my body prefers to run and what helps it perform optimally. Evening snacks are here to stay (for me), and the right one can stabilize overnight glucose levels.
How I Adjusted: Adding Back Strategic Evening Snacks
Life is about adjusting to the circumstances. To ensure I have optimal energy and reduce my chance of a debilitating migraine caused by low blood sugar levels, I include evening snacks in the following situations:
- Earlier dinner nights due to evening activities away from home
- When I have morning walks planned
- On high-stress days (or weeks)
What those snacks look like:
- Protein + fiber-rich carbohydrate (click the link for an article detailing some of 10 best snacks you can buy and criteria for a balanced snack)
- Not sugary, not oversized (not a large French fry or potato chips)
Some examples include:
- Cottage cheese and fruit
- Peanut butter and sliced apples
- Hummus, crackers, and carrots
- Cheese and crackers
- No-added-sugar Greek yogurt with peanut butter and a few dark chocolate chips
- Energy bites (recipe)
Strategic snacks are a crucial part of my eating plan to improve glycemic control, reduce migraines, and maintain adequate energy.
Remember, this was a personalization of how removing evening snacks backfired for me. This is not a rigid rule for all people. Some may need to remove evening snacks to better control their intake and glucose levels, or change the types of snacks they consume in the evening.
Takeaways
This CGM follow-up reinforces a core UNstuck Nutrition principle: nutrition works best when it’s individualized, flexible, and not rule-based. We are always changing, and so are our eating habits and nutritional needs!
Removing evening snacks without ensuring I was making up that nutrition throughout the day, alongside some stressful life events, pushed my glucose too low and contributed to migraines that weren’t responding to my interventions as usual. I recognized the patterns after a few days and added back strategic snacks to restore my glucose stability.
The real lesson isn’t “snacks are good or bad,” but that listening to your body’s signals and using data (when needed) to guide adjustments keeps you UNstuck and functioning well. Health is built from patterns, not isolated readings.
Healthy habits and listening to your body can help you feel your best. Read the first 2-week CGM experiment here!
You might also be interested in how to design meals with anti-inflammatory foods and learn to use the plate method to balance nutrients and fuel your body optimally, or how long it might take to see results following an anti-inflammatory diet.
Let’s get UNstuck and stay UNstuck!