A Wake-Up Call About Sleep

When Why We Sleep was published in 2017, it changed the way people think about sleep. Neuroscientist Matthew Walker makes a compelling case that sleep is not just a passive state but a fundamental pillar of health, just as critical as diet and exercise. He argues that neglecting sleep affects every part of well-being – from memory and mood to heart health and the immune system.

Walker presents a wealth of scientific evidence showing that chronic sleep deprivation is linked to a higher risk of obesity, diabetes, Alzheimer's and even a shorter lifespan. Despite this, society has long treated sleep as an afterthought, placing productivity above rest.

His message is clear: making sleep a priority is one of the most effective ways to improve health and longevity.

The Key Scientific Insights

1. The Functions of Sleep

Walker explores how sleep is essential for memory consolidation, emotional balance and brain detoxification. During deep sleep, the brain strengthens neural connections, clears out waste products like beta-amyloid (linked to Alzheimer’s) and prepares the body for the day ahead. Rapid Eye Movement (REM) sleep, on the other hand, plays a key role in creativity and emotional resilience.

2. The Consequences of Sleep Deprivation

The book leaves no doubt about the dangers of too little sleep. Walker shows that even mild sleep deprivation can impair cognitive function, weaken the immune system and increase the risk of chronic disease. Studies reveal that routinely sleeping fewer than six hours per night raises the risk of heart disease, stroke and early death.

3. Caffeine, Alcohol and Modern Sleep Disruptors

Walker doesn’t just explain why sleep is vital – he also examines what’s getting in the way. He highlights how caffeine blocks adenosine, the brain chemical that makes us feel sleepy, and how alcohol fragments sleep, reducing its quality even when it feels like it helps with relaxation. He also warns about the impact of artificial light, particularly blue light from screens, which interferes with the body's natural sleep-wake cycle by suppressing melatonin production.

4. The Myth of Short Sleepers

Many people claim they can function well on five or six hours of sleep, but Walker argues this is an illusion. Cognitive testing shows that even those who believe they are unaffected by sleep loss perform worse on mental tasks. Sleep deprivation also dulls self-awareness, making it hard to recognise the effects.

The Impact of Why We Sleep

Since its release, Why We Sleep has been a game-changer. It has sparked a global conversation about sleep and influenced individuals, businesses and even government policies. More people are recognising that sleep is a cornerstone of longevity, productivity and mental well-being.

Despite the book’s success, some scientists have criticised Walker for occasionally overstating claims or presenting worst-case scenarios as universal. However, the core message remains undisputed – sleep is a biological necessity and skimping on it carries serious consequences.

Where Are We Now? The Latest in Sleep Science

Since Why We Sleep was published, research has continued to reinforce its main points. Studies confirm that optimising sleep improves memory, mood, metabolic health and lifespan. The science of sleep tracking, sleep-enhancing supplements and personalised sleep interventions is evolving rapidly, with new insights into how individuals can improve sleep quality.

The biggest takeaway from Walker’s work is simple: sleep isn’t a luxury, it’s a necessity. Understanding and respecting its role is one of the most powerful things we can do to protect long-term health and well-being.

A Fresh Take on Blood Sugar and Health

Jessie Inchauspé, known as the "Glucose Goddess," has brought blood sugar science into the mainstream with Glucose Revolution. The book presents a simple but powerful argument – managing blood sugar isn’t just for diabetics. Keeping glucose levels stable can improve energy, reduce cravings, support weight management, and even enhance long-term health by lowering inflammation and disease risk.

What makes this book stand out is its accessible, practical approach. Inchauspé doesn’t overload the reader with dry science. Instead, she blends personal anecdotes, real-world experiments, and clear, actionable tips that anyone can follow. The book makes the case that balancing blood sugar isn’t about extreme diets – it’s about small tweaks that make a big difference.

Key Insights from Glucose Revolution

1. The Blood Sugar Rollercoaster

When we consume high-sugar or refined-carb foods on an empty stomach, we experience rapid spikes in blood glucose. This is often followed by an equally sharp crash, leading to fatigue, cravings, and hunger soon after eating. These swings put stress on the body, contribute to inflammation, and can accelerate aging. Inchauspé explains how avoiding these extreme fluctuations is key to feeling better and staying healthier.

2. Food Order Matters

One of the book’s biggest takeaways is that the order in which we eat food affects glucose response. Eating fibre, protein, and fat before carbohydrates slows glucose absorption, preventing big spikes. Simple swaps – like starting a meal with a salad or pairing fruit with nuts – can have a significant impact on energy levels and hunger control.

3. Vinegar: A Surprising Ally

Inchauspé highlights how a tablespoon of vinegar before a meal can reduce glucose spikes by slowing carbohydrate breakdown and absorption. This well-supported strategy has been shown to improve insulin sensitivity, making it an easy and effective tool for better metabolic health.

4. Movement After Meals

Exercise isn’t just for fitness – it plays a crucial role in blood sugar regulation. A short walk or light movement after eating helps muscles absorb glucose, reducing post-meal spikes. This simple habit can help prevent energy crashes and support long-term metabolic health.

5. Breakfast Can Set the Tone for the Day

A carb-heavy breakfast often leads to an energy rollercoaster, leaving people sluggish and hungry by mid-morning. Instead, prioritising protein and healthy fats at breakfast can stabilise blood sugar, leading to better focus, steady energy, and fewer cravings throughout the day.

The Impact of Glucose Revolution

The book has been a game-changer for many, making metabolic health more accessible and actionable. It has resonated with a wide audience, from those struggling with energy crashes to people looking for simple, sustainable ways to support long-term health. Inchauspé’s approach isn’t about restriction – it’s about harnessing science to make food work for you, rather than against you.

While the book has been widely praised, some critics argue that not all of its strategies will work equally well for everyone. For example, while vinegar can blunt glucose spikes, its effects may be more pronounced in some individuals than others. Additionally, the book simplifies complex metabolic processes, which can sometimes make the science feel overly black-and-white. However, the core principles – avoiding glucose spikes, optimising food order, and using movement strategically – remain well-supported by research.

Where Are We Now? Blood Sugar Science in 2025

Since the book’s release, interest in blood sugar management has skyrocketed. Continuous glucose monitors (CGMs), once used primarily by diabetics, are now being embraced by a wider audience for personalised health insights. More research is also emerging on the long-term impact of glucose spikes on aging and chronic disease, reinforcing the importance of stable blood sugar beyond just diabetes prevention.

The biggest takeaway from Glucose Revolution is that small changes can lead to big improvements. Understanding and managing blood sugar is a powerful tool for better energy, improved mood, and long-term health – and thanks to Inchauspé, more people than ever are paying attention.