You might say that lately, sugar is the spoon that stirs the storm in the nutrition teacup. From the surge in continuous glucose monitors (CGMs) among healthy individuals to viral nutrition influencers challenging conventional dietary advice, sugar has found itself in the spotlight. But how much of what we hear is grounded in science? And what role does sugar really play in our health, weight, and gut microbiome?
Let’s cut through the noise and unpack what we actually know about sugar, how it interacts with our body, and what we can do to consume it more wisely.
Sugar: Not All Carbs Are Created Equal
Sugar is a type of carbohydrate, and carbohydrates come in many forms: sugars, starches, and fibre. Our bodies break down most carbs into glucose, the body’s main source of energy. But not all sugars are created (or processed) equally.
There are naturally occurring sugars found in fruits, vegetables, and dairy products, and then there are added sugars found in processed foods like biscuits, soft drinks, and sauces. The latter, stripped of fibre and other nutrients, are what health professionals recommend we limit.
Consuming too much added sugar is linked to a host of health concerns, including:
- Obesity: Excess sugar contributes to weight gain by providing empty calories and promoting fat storage.
- Type 2 Diabetes: Chronically elevated blood glucose levels, often driven by poor lifestyle choices (e.g low low-quality, high-energy food and lack of exercise), can increase insulin resistance. Important to note that there is no clear evidence to suggest that high sugar intake in children leads to Type 1 Diabetes, where all insulin-producing cells are destroyed in this autoimmune disease.
- Cardiovascular Disease: High sugar intake is associated with increased triglycerides, inflammation, and high blood pressure.
But what about sugar in fruit? Unlike added sugar, the sugar in fruit comes with fibre, water, and a host of micronutrients that modulate how it affects blood glucose levels. In short, context matters.
Understanding Glucose Spikes: Should You Worry?
Continuous glucose monitors (CGMs) have become popular tools for tracking how different foods affect blood sugar, even among people without diabetes. Books like The Glucose Revolution have popularized the idea of “flattening the glucose curve” to prevent energy crashes, cravings, and long-term health issues.
But how much of this is backed by science?
Short-term glucose spikes, especially after meals, are perfectly normal. For most healthy people, the body regulates these efficiently through insulin. It’s the chronic elevation of blood sugar, seen in prediabetes or unmanaged type 2 diabetes, that causes concern.
One reason? Long-term high blood sugar can lead to the formation of Advanced Glycation End-products (AGEs). These molecules form when excess sugar binds to proteins or fats and contributes to:
- Oxidative stress
- Inflammation
- Damage to blood vessels
- Accelerated aging of skin and organs
- Increased risk of cardiovascular disease, kidney damage, and neuropathy
So while monitoring glucose might offer insights, especially for personalization, it’s important not to over-pathologize natural, temporary spikes or develop an obsessive relationship with food.
Sugar and Your Gut: The Forgotten Connection
While the long-term effects of high blood sugar can lead to internal damage via AGEs, there’s another major system sugar affects that’s gaining attention in recent years: your gut microbiome.
Emerging research is drawing a fascinating link between sugar intake and the health of our gut microbiome, the trillions of bacteria and other microorganisms living in our intestines.
A diet high in added sugars and refined starches can lead to gut dysbiosis, an imbalance in gut bacteria. This, in turn, has been associated with a higher risk of:
- Chronic inflammation
- Metabolic disorders
- Type 2 diabetes
- Mood disorders and even neurodegenerative diseases
One of the mechanisms? Diets rich in added sugar can reduce the diversity of the microbiome and suppress the growth of beneficial bacteria that thrive on fibre.
Conversely, dietary fibre, particularly prebiotic fibre found in fruits, vegetables, legumes, and whole grains, acts as fuel for good gut bacteria. This fermentation process produces short-chain fatty acids (SCFAs), which help regulate inflammation, support the immune system, and may even improve insulin sensitivity.
One of the more alarming trends in modern health is the sharp rise in colorectal cancer among adults under 50. While genetics plays a role, emerging research suggests that diet and gut health are key contributors to this shift. The typical Western diet, high in added sugars, refined carbs, and low in fibre, may disrupt the gut microbiome, fueling chronic inflammation and damaging the colon lining over time. Studies have shown that low fibre intake and high consumption of sugary beverages during adolescence are linked to a greater risk of developing precancerous colon growths later in life. Without enough fibre, the gut produces fewer short-chain fatty acids like butyrate, which normally help protect against inflammation and cancer. This growing crisis underscores the need to prioritise gut-friendly, high-fibre foods from an early age, not just for digestive wellness, but as a crucial pillar of long-term disease prevention.
Personalized Nutrition: One Gut Doesn’t Fit All
Thanks to microbiome science and innovations from companies like Zoe Nutrition, we now understand that our response to food is highly individual. Two people can eat the exact same meal and experience very different blood sugar responses, influenced by their genetics, microbiome, sleep, stress levels, and more.
This realization is shifting nutrition away from one-size-fits-all rules. While broad advice like “limit added sugars” still stands, tailoring your diet based on how your body actually responds can be a game-changer.
For example, some people may handle starches well but struggle with simple sugars; others may find that fruit spikes their glucose more than expected. But again, the presence of fibre, both in the food and in the overall diet, is a major protective factor. If you are in the group that has high spikes in blood glucose, and you eat porridge every single day for breakfast, this information could allow you to adapt to another choice that suits your body better.
The Fibre Fix: Your Gut’s Best Friend
If there’s one dietary tweak that delivers huge health benefits across the board, it’s increasing fibre intake. Most adults fall far short of the recommended 25-30 grams per day.
Here’s why fibre matters:
- Regulates blood sugar by slowing down digestion and glucose absorption.
- Feeds good bacteria in your gut, promoting a diverse and resilient microbiome.
- Improves satiety, helping with weight management.
- Supports regularity and reduces the risk of colon cancer.
One of the most practical ways to boost your fibre is by incorporating whole, plant-based foods into your routine.
Smart Strategies to Reduce Sugar and Boost Fibre
Here are a few simple, science-backed ways to adjust your diet without becoming a glucose-monitoring zealot:
- Start meals with veggies: A fibre-rich starter can blunt the blood sugar impact of carbs that follow.
- Choose whole fruit over juice: Whole fruit retains fibre; juice does not.
- Read labels: Watch out for hidden sugars in sauces, yoghurts, and “healthy” snacks.
- Use natural sweeteners sparingly: Stevia, monk fruit, or dates can sweeten foods with less glycaemic impact.
- Snack on fibre: Reach for hummus with veg or a handful of nuts.
- Batch cook beans and lentils: These are fibre powerhouses and versatile meal builders.
- Go slow with starches: Choose intact grains like barley or quinoa over refined white rice or pasta.
Take Home Message: It’s Not About Fear, It’s About Balance
Sugar isn’t inherently evil. In fact, your body needs glucose to function. What matters is context: where that sugar comes from, how it’s delivered, and what your overall dietary pattern looks like.
Instead of chasing every new diet trend or obsessing over glucose spikes, focus on sustainable habits that support your gut, your energy, and your long-term health. A high-fibre, minimally processed, plant-rich diet does more than just prevent disease — it helps you thrive.
