15-Days Glucose Level Monitoring - 5 Findings from a Nutritionist

15-Day Blood Glucose Level Monitoring

Over 15 days, I tracked my blood glucose levels using a FreeStyle Libre 3 continuous glucose monitor (CGM) to understand how food, exercise, and sleep affect metabolic health. Here’s what I found:

 Here’s what I found:

• Stable baseline: My average glucose was 5.2 mmol/L, with a Glucose Management Indicator (GMI) of 5.5 % and 99% time in range (3.9–7.8 mmol/L),
  excellent for a non-diabetic individual.
• Biggest spikes: Fruit juice, white rice, and processed foods like Döner kebab with pita caused short-term rises to ~7.5 mmol/L, confirming that refined carbs and liquid sugars drive quick glucose increases.
• Best stabilizers: Exercise, quality sleep, steady meal timing, protein-rich meals, fibre, vegetables and post-meal movement (a 10-minute walk) kept glucose “boringly stable.”
• My main takeaway: Even for healthy people, tracking blood glucose levels for two weeks reveals valuable insight into metabolic health, insulin sensitivity, and lifestyle impact.

Before diving more into the science of glucose levels and jumping straight to my main takeaways, let’s first cover the basics.

What is glucose?

In simple terms, glucose is the primary fuel molecule that powers almost every cell in your body.

• After you eat food that contains carbohydrates (like starches, sugars, grains or fruits), the digestive system breaks them down into glucose (and other simple sugars).
• That glucose enters your bloodstream, raising your blood sugar.

From there, glucose is absorbed into cells—especially muscle, brain, and organs—to support energy production, via a tightly regulated hormonal system.

• When blood glucose rises, the pancreas releases insulin, which helps cells take in the sugar for immediate use or storage (as glycogen in the liver, or in fat).
• When glucose drops too low, glucagon signals the liver to release stored glucose. Together, this balance is called glucose homeostasis.

Okay, but what’s the connection between glucose (blood sugar) and metabolic health?

What are the risks if blood sugar levels are chronically elevated?

Why did I monitor my Blood Glucose Levels?

As a child / teenager, I was always doing sports, mainly playing football, so I was always rather athletic, but skinny.

In my 20s, I added weight training to my routine. Now, at the age of 31, it becomes less about optimizing my sports performance, but rather about training for health.

I am training mainly for longevity related purposes, to ensure that later in life, I can still do the things I love. My training consists of weight training 4x a week, Zone-2 cardio 2x a week (e.g. running, bike, playing padel or football) and Vo2 Max training 1x a week (running, bike).

So if I have never been overweight and have never been at risk to develop pre-diabetes or diabetes type-2, why did I bother to monitor my blood glucose levels?

In short, the main reason is that there is increasing scientific evidence that not only chronically elevated glucose levels are harmful, but also big glucose spikes may impact health more than was previously believed. And I am not only looking to avoid disease, I am looking to optimise my health. Both physically and mentally so I can perform at my best, be there for other people when they need me and follow my personal (and Naturecan’s) mission to “help as many people and pets as possible to live a healthier, happier and longer life.” So I got curious. Which foods impact my glucose levels the most? How can I avoid not only chronically elevated glucose levels, but also big glucose spikes?

What are normal blood sugar levels?

To know what’s “safe,” here are widely accepted reference ranges for healthy individuals (non-diabetic) in everyday settings:

Fasting (after 8+ hours without food)

• Safe: ~ 4.0 to 5.4 mmol/L (≈ 72 to 99 mg/dL)
• Optimal: ~ 4.0 to 5.0 mmol/L (≈ 72 to 90 mg/dL)

Two hours after a meal (postprandial)

• Safe: up to ~ 7.8 mmol/L (≈ 140 mg/dL)
• Optimal: up to ~ 6.7 mmol/L (≈ 120 mg/dL

For example, the British Heart Foundation states that healthy adults often fall in those ranges.
These values are guides — some labs or health authorities may have slightly different cutoffs.

Clinically, when fasting glucose rises above ~ 7.0 mmol/L (≈ 126 mg/dL) or post-meal levels exceed ~ 11.1 mmol/L (≈ 200 mg/dL), that can indicate diabetes. [11]

What Blood Glucose Monitor did I use?

I initially wanted to try the Dexcom Stelo Glucose Biosensor, but it’s not yet available in Germany, so I opted for the FreeStyle Libre 3 Sensor, a continuous glucose monitor (CGM).

The setup was simple: after attaching the small sensor to the back of my arm (see the picture), it connected seamlessly to the app within about an hour. The sensor costs 70€ in Germany and lasts for 15 days. 

The FreeStyle Libre 3 app offers a clear and comprehensive dashboard where you can:

• View real-time and historical glucose data
• Track your time in range and personalize target zones
• See average glucose levels and identify low or high episodes
• Add notes on meals, exercise, or sleep
• Receive alerts when glucose levels rise or fall rapidly (especially useful for people with diabetes)

It's very simple to use CGM to visualize how food, activity, and stress affect blood sugar day-to-day.

What were my main findings of monitoring blood glucose levels for 15 days?

Over the two-week tracking period (28 September – 11 October 2025), my readings showed an impressively stable glucose profile.

Summary of my glucose data

• Average glucose: 5.2 mmol/L
• Fasting Glucose: 4.9mmol/L
• Glucose Management Indicator (GMI): 5.5 % (≈ 37 mmol/mol HbA1c)
• Time in range (3.9 – 7.8 mmol/L): 99%
• Time above or below range: 1%
• Typical daily pattern: Smooth curve between 4.5 – 6.5 mmol/L with small, short-lived peaks after meals

These metrics fall well within the optimal range for non-diabetic individuals, suggesting excellent metabolic control and insulin sensitivity.

The standard deviation appears very low, with a smooth 24-hour profile and minimal glycemic variability. This is a key predictor of metabolic health - stable glucose with small meal peaks (<6.7 mmol/L) indicates:

• Excellent mitochondrial efficiency and insulin sensitivity
• Low risk of glycation-related aging (AGE formation)
• Consistent energy metabolism and cognitive stability
  ✔ Metabolic health: Excellent
  ✔ Insulin sensitivity: Strong
  ✔ Glucose variability: Minimal

How to keep blood glucose levels low? My top 5 advice

After comparing notes, meal logs, and activity data, several consistent patterns emerged:

1. Exercise

Working out and maintaining a healthy weight and body composition is one of the most effective ways to keep blood sugar levels low in the long-term. I train around six times a week:

• 4 weight training sessions focused on strength and muscle maintenance.
• 2–3 cardio sessions, including one high-intensity VO₂ Max workout and one to two lighter Zone 2 sessions (running, cycling, or padel).

Exercise, especially when consistent, increases insulin sensitivity, allowing muscles to absorb glucose more efficiently — even hours after training. [2]

2. Balanced Meals with Protein and Fibre

Pairing carbohydrates with protein (chicken, meat, fish, eggs, yogurt) or fibre (vegetables, legumes, whole grains) clearly blunted my post-meal spikes.

A meal that combined all three — for example:
grilled chicken, vegetables, salad and a small portion of rice or pasta — produced a smooth, steady glucose curve.

3. Physical Activity After Eating

After lunch (and sometimes after dinner), I often do a 10-minute treadmill walk at about 3 km/h. Even light activity like this noticeably flattened my glucose curve. This aligns with research showing that post-meal movement improves glucose uptake and insulin sensitivity. [12]

4. Steady Meal Timing

I usually eat two main meals per day and sometimes a small snack if needed. Eating at consistent times helps maintain a smooth baseline.

• Morning: I’m rarely hungry when I wake up, so after my workout, I typically only have a protein shake around 9 a.m. and stay hydrated. I take a delicious Naturecan Clear Whey protein shake (20g protein, 87 kcal, no carbs, no sugar, no glucose spikes). If I eat breakfast, it’s simple — three eggs — with plenty of protein to keep my glucose levels nice and steady.
• Lunch (around 12:30 p.m.): A balanced meal with protein, carbs (rice, pasta, potatoes), and plenty of vegetables or salad. I limit sauces, as many contain crazy high amounts of sugar.
• Afternoon (occasionally): If I get hungry, I go for a high-protein snack such as Skyr yogurt with FlavPowder or another protein shake. I also mix in my daily creatine (8g, 1g per 10kg body weight) mainly for strength and cognitive benefits and magnesium for recovery and better sleep quality.
• Dinner (6:30–7 p.m.): Usually this is my biggest meal — protein, vegetables, healthy fats, and some carbs.

• Eating earlier improves my HRV and sleep quality, since late dinners keep my body busy digesting.
• Occasionally, like once a week, I enjoy a pizza or Döner kebab.
• If I have dessert, it’s always after dinner, never as a standalone snack. I love ice cream, but timing makes all the difference for glucose stability.

Before going to bed at around 10pm - 10.30pm: I take the rest of my supplements. Vitamin D3/K2 for my immune system and bone health, Omega-3 for heart and brain health, KSM-66 Ashwagandha to reduce cortisol levels, curcumin to lower inflammation and multivitamin for the immune system mainly.

5. Sleep and Stress Management

I sleep around 8 – 8½ hours per night and take a 10-minute nap daily — one of my favourite rituals for recovery. Poor sleep or high stress correlates with slightly higher morning glucose readings, likely due to cortisol’s effect on glucose regulation and circadian rhythm. Prioritising recovery is non-negotiable for me to keep both my mental and physical performance and my glucose steady.

Foods That Spiked My Glucose the Most

Although my levels stayed within range overall, a few foods caused short-term peaks:

• Fruit juices: I rarely drink them because they deliver a large sugar load with no fibre, leading to a rapid rise to about 7.5 mmol/L within 20 minutes. This experiment just confirms for me that sticking to eating fruits, not drinking them, is a much better choice. I try to avoid as many calories from drinks in general as possible, opting mostly for water and protein shakes and sometimes a coffee or Pepsi Max (no sugar, no calories). The only calories I consume through drinks really are protein shakes. A delicious, convenient and low-calorie way to increase my overall daily protein intake. E.g Naturecan Clear Wheys contain 20g of protein, but only 87kCal. I always mix my protein with my daily creatine and magnesium.
• White rice, pasta: Not surprisingly, large portions caused spikes up to 7.5 mmol/L. However, as I am metabolically healthy and as I normally mix them with other types of food (protein, fibre), I will continue eating white rice as it tastes better for me. If I was overweight and wanted to lose weight, I’d opt for brown rice, potatoes or quinoa e.g. instead.
• Pizza / Döner kebab with pita bread: The combination of refined carbs and fat led to a higher, longer-lasting glucose rise. Occasionally, I’ll still treat myself though. It’s not aiming for perfection, rather just being aware and a balance of enjoying treats once in a while.
  
  These spikes were mild and short-lived, but they highlight how processed carbs and liquid sugars can elevate glucose even in people with healthy metabolism.
  
  Overall, my glucose levels stayed remarkably stable throughout the two weeks.
  

Did I use the 10 Glucose Goddess Hacks?

Jessie Inchauspé, also known as The Glucose Goddess, is a French biochemist and author who popularised practical, science-backed strategies to help stabilise blood sugar levels. She wants to help people avoid energy crashes, cravings, and long-term metabolic stress by flattening their glucose curves — all without restrictive dieting or obsessive calorie counting.

She shares what she calls the 10 Glucose Goddess Hacks, which are small, evidence-based adjustments in how and when you eat. These hacks are designed to improve glucose stability, boost energy, and support metabolic health — even for people without diabetes.

During my 15-day glucose experiment, I put several of these hacks to the test. Here’s how I applied them and what I learned.

1. Eat your food in the right order — Mostly yes

Jessie’s first rule is to eat vegetables first, then protein and fat, and finally carbohydrates. This simple order slows digestion and reduces the height of post-meal glucose spikes. I followed this principle for most meals — having a small salad or cooked vegetables before my main dish. Looking at my overall results, this seemed to work well and will be something I pay attention to in the future. My assumption also is, if one starts with vegetables or salad, the overall amount of carbs one eats are lower vs. when starting directly with the “main carb dish”.

2. Add a vinegar shot before meals — No

Another popular Glucose Goddess hack is drinking one tablespoon of apple cider vinegar in a glass of water before eating. The acetic acid can help reduce post-meal glucose and insulin levels (Johnston et al., 2004, Diabetes Care). I didn’t test this one during the 15 days. I don’t like the taste at all. As I am metabolically healthy, I personally will skip this one. If I was metabolically unhealthy, I’d opt for Naturecan’s Sugar Free Apple Cider Vinegar Gummies instead that have a much better taste.

3. Stop counting calories — Yes

Instead of focusing on calorie counting, Jessie encourages paying attention to how foods affect your glucose. In general, I think understanding calories is more important than understanding glucose. So tracking calories for a short amount of time e.g. for people who want to lose fat and want to gain a better understanding or for professional athletes, I don’t think it's necessarily a bad thing. I tracked calories and macros for around two weeks some years ago just to get a better understanding.

However, for me personally, the time-benefit trade off is not there. I just try to eat overall balanced meals with protein, fibre, and healthy fats that keep me full and stable for long.

4. Eat a savoury breakfast — Kind of

Jessie recommends starting the day with a savoury, protein-rich breakfast rather than sugary cereals or pastries. I usually skip breakfast altogether or have a protein shake or eggs. However, I don’t necessarily see it as a bad thing if something starts the day with a high protein yogurt and berries (sweet) e.g.

But I fully agree that breakfast sets the tone for the entire day, so starting your day with protein instead of sugar, this will probably have one of the best impacts on your energy levels throughout the day without crashes or mid-morning hunger.

5. Walk after eating — Sometimes

A 10–15 minute walk after a meal is one of the simplest ways to help muscles absorb glucose and flatten post-meal spikes [12]. I don’t always manage this, but when I do — especially after lunch — the results are visible and my glucose curve becomes noticeably smoother. So I’ll try to keep this up.

6. Dress your carbs — Yes

This hack is about “dressing up” your carbs with fibre, fat, or protein — for example, adding vegetables, fish or avocado (healthy fats, but high in calories) to my pasta or rice. I always do this almost automatically as the healthy fats, protein and fibre-rich foods to carb-heavy meals keeps my blood sugar levels stable.

7. Have dessert after your meal — Yes

This hack basically says that if you eat something sweet, don’t “snack” it throughout the day, but have it after a meal as this will cause a lower glucose level spike. I do follow this advice. If I occasionally eat something sweet, e.g. ice cream, I only do it after dinner, and while there is a spike in glucose levels, eating the same dessert alone would cause a higher spike.

Additionally, limiting low-nutrient high caloric food to the evening will help you to manage the overall amount of calories you eat throughout the day. If you have a high sugar breakfast (cereals), a chocolate bar in the morning, a small piece of cake in the afternoon and then have dinner with dessert, you’re most likely going to be in a caloric surplus.

8. If you have to snack, go savoury — Not really

Jessie recommends choosing savoury, protein-based snacks over sweet ones to avoid unnecessary spikes. Protein rich I fully agree, but again, I don’t think it necessarily needs to be savoury.

I don’t snack often, but when I do, I usually go for Skyr yogurt with FlavPowder or a protein shake. These are both low in sugar, high in protein, and easy on glucose levels.

9. Try a vegetable starter — Mostly yes

This one for me is very similar to the first glucose goddess trick, so the same answer as for number one, this simple hack is helpful for me to keep blood glucose levels steady and overall eat less carbs / calories.

10. Have any type of sugar, they’re all the same — Yes

I am fully aligned with this point. Many people drink fruit juices, smoothies or eat dried fruits, honey, a fruit marmalade or granola e.g. with the goal to consume something healthy and do something good for the body. However, these are very high in sugar that will spike your blood sugar levels a lot, especially when eaten as a snack alone.

So instead, always keep balance in mind, if you eat something sweet that is high in sugar, then at least fully enjoy it. If I eat I make sure it’s part of a meal or as dessert (ice cream, chocolate e.g.).

11. Take Anti-Spike Supplement — Kind of

While I didn’t take Jessie Inchauspé’s branded supplement, on some days before dinner (my meal with the highest amount of carbs) I did take Naturecan’s Glucose Support Capsules. This product contains the same key active ingredient, 250mg of Reducose®, but at a more affordable cost. The idea behind glucose tablets or capsules is that they can blunt post-meal spikes by up to 40%.

GLP-1 Bundle

£68.81

Add To Cart

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Clear Whey Protein Isolate

£35.09

Peach Ice Tea / 1kg - £35.09 Peach Ice Tea / 2kg - £70.99 Orange & Mango / 1kg - £35.09 Berry / 1kg - Sold out Tropical / 1kg - Sold out

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High Strength Omega-3 Supplement

£16.99

90 Capsules - £16.99 180 Capsules - £31.99

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Glucose Support Capsules

£34.99

60 Capsules - £34.99 120 Capsules - £64.99 180 Capsules - £90.99

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My verdict: The Glucose Goddess hacks aren’t magic, but they’re incredibly practical. A nutrient-rich high protein diet, together with meal structure, food pairing and light movement, can be simple ways how one can maintain a much smoother glucose curve.

The above paired with the basics - exercise (combination of resistance and cardiovascular training), quality sleep (at least 7h), stress management and a balanced diet, are the pillars for maintaining overall blood sugar levels more stable / lower and overall for metabolic health.

Conclusion: Will I monitor my blood glucose levels in the future?

Was tracking my glucose levels for 15 days beneficial for understanding my metabolic health, my average glucose trends, and what drives my blood sugar spikes? Absolutely, yes.

This short experiment gave me a clear picture of how my body reacts to food, exercise, sleep, and stress. It confirmed that my glucose levels are stable, my insulin sensitivity is strong, and my lifestyle habits — exercise, balanced meals, and recovery — are working well for me.

What I Learned

Tracking glucose is insightful and surprisingly convenient. Attaching the CGM sensor to my arm was simple, and having all the data available instantly through the app made it easy to monitor trends in real time.

However, much like calorie tracking, the true benefit for me lies in the initial learning phase. Two weeks of continuous data already provided me with all the insights I needed to fine-tune my habits and verify assumptions. Once those patterns are clear, ongoing tracking adds less value — especially for someone who is already metabolically healthy.

Why I Won’t Keep Tracking (for Now)

The main reason I won’t continue glucose tracking is cost. At around €70 every 15 days, the cost-to-benefit ratio doesn’t justify continuous use for me personally for a healthy, active person. I already train six times per week, eat a diet rich in protein, fibre, and vegetables, and get around eight hours of sleep each night. These are the real foundations of good metabolic health — and I don’t aim for perfection. I aim for consistency and balance.

My Key Takeaway

Health tracking should empower, not overwhelm. Once you’ve gathered enough data to understand your body, it’s more valuable to apply those learnings in daily life than to monitor endlessly. I’m grateful for the insights this experiment provided — and I hope reading this summary helped you take away a few practical tips as well.
Remember: small, sustainable steps go a long way.

• Prioritise protein, fibre, and vegetables.
• Avoid sugary drinks.
• “Dress” your carbs with protein, fats or fibre.
• Move lightly after meals.
• Exercise.
• Manage your sleep and stress.

Do these consistently, and your glucose — and overall health — will thank you.

Yours,
Alexander Rinn Ortiz
Nutritionist and eCom MD of Naturecan

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