What is blood sugar and why does it matter?
Blood sugar, or blood glucose, refers to the amount of glucose circulating in your bloodstream at any given time. Glucose is your body's primary source of energy — it fuels your brain, muscles, and organs throughout the day.
When you eat carbohydrates, your digestive system breaks them down into glucose, which enters the bloodstream. Your pancreas responds by releasing insulin, a hormone that helps cells absorb glucose for energy or store it for later use.
When this system works well, blood sugar stays within a healthy range. When it doesn't, blood sugar can rise too high after meals, stay elevated for extended periods, or fluctuate in ways that affect how you feel day to day.
Consistently elevated blood sugar is one of the most common and most preventable drivers of long-term health complications in adults over 40.
Signs that blood sugar may be out of range
Blood sugar imbalance doesn't always produce obvious symptoms, which is why it often goes unaddressed for years. Some of the more common indicators include:
- Persistent fatigue, especially after meals
- Strong cravings for sugar or carbohydrates
- Difficulty concentrating or mental fog
- Increased thirst or frequent urination
- Unexplained weight gain, particularly around the midsection
- Mood changes or irritability between meals
- Slow wound healing
If you recognise several of these symptoms, it is worth speaking with your healthcare provider and requesting a fasting blood glucose or HbA1c test.
What influences blood sugar levels?
Blood sugar is not just determined by what you eat. A range of lifestyle factors play significant roles:
- Diet: Refined carbohydrates and sugary foods cause rapid spikes. Fibre, protein, and healthy fats slow glucose absorption and reduce peaks.
- Physical activity: Exercise increases insulin sensitivity, helping your cells use glucose more effectively. Even a 20-minute walk after meals can meaningfully lower post-meal glucose.
- Sleep: Poor sleep impairs insulin sensitivity and increases cortisol, both of which raise blood sugar. Consistently sleeping less than 7 hours is associated with higher fasting glucose levels.
- Stress: Chronic stress elevates cortisol, which signals the liver to release more glucose into the bloodstream — even without eating.
- Hydration: Dehydration concentrates glucose in the blood. Drinking sufficient water throughout the day supports more stable levels.
Natural approaches to supporting healthy blood sugar
There is strong evidence that lifestyle changes can significantly improve blood sugar regulation. The most impactful approaches include:
- Eating meals with a balance of protein, fibre, and healthy fat before carbohydrates
- Reducing refined sugar and ultra-processed foods
- Incorporating regular moderate exercise, particularly after meals
- Prioritising 7–9 hours of sleep per night
- Managing stress through structured practices such as walking, breathing exercises, or mindfulness
Each of these areas has substantial clinical research behind it. The most promising news from the literature is that meaningful improvement is possible — in many people — through deliberate, consistent practice of a small number of foundational habits. The articles in my Metabolic Education section explore each of these areas in greater depth.
When to speak with a doctor
This article is for general informational purposes only and does not constitute medical advice. If you have concerns about your blood sugar, are experiencing symptoms, or have a family history of diabetes, please consult a qualified healthcare provider. A simple blood test can give you a clear picture of where your levels stand.