5 Reasons to Get a Good Night Sleep

Sleep is not a luxury — it is a vital pillar of metabolic health, right alongside low carb nutrition, mindset and movement. The impact of poor sleep goes far deeper than simply feeling tired. It affects hormones, brain function, immune defences and even your ability to make supportive food choices.

Here are five evidence-based reasons why prioritising sleep is one of the most powerful things you can do for your health:

#1 Sleep Helps Regulate Your Weight and Metabolism

When you sleep well, your body maintains a healthier hormonal balance — especially the hormones that control hunger and fullness. Ghrelin tells you you’re hungry; leptin signals satiety. Poor sleep skews this balance, increasing ghrelin and reducing leptin, which leads to more frequent and intense hunger, particularly for high sugar and high carbohydrate foods. This is not about weak willpower — it’s a physiological response to sleep deprivation.

Short sleep duration is also associated with insulin resistance, which increases fat storage and contributes to the development of type 2 diabetes. Chronic under-sleeping disrupts glucose metabolism, making it harder for your body to use energy efficiently.

📚 Reference: Spiegel K, et al. Leptin levels are reduced and ghrelin levels are increased in short sleep duration. PLoS Med. 2004 Dec;1(3):e62.
PMID: 15596622

#2 It Improves Mood and Mental Health

Sleep is essential for emotional stability. During healthy sleep, activity in the amygdala (the brain’s fear and reactivity centre) is regulated by the prefrontal cortex. When you don’t get enough rest — especially REM sleep — this regulation falters. The result? Increased emotional reactivity, anxiety, irritability and poor coping skills. Over time, chronic sleep deprivation has been linked to a higher risk of depression, anxiety disorders and burnout.

In short, a well-rested brain responds rather than reacts. This helps you remain calm, set boundaries, and make decisions that support long-term wellbeing.

📚 Reference: Baglioni C, et al. Sleep and mental disorders: A meta-analysis of polysomnographic research. Psychol Bull. 2016 Sep;142(9):969–90.
PMID: 27148759

#3 It Supports Brain Function and Memory

Sleep is not passive — your brain is actively doing important work overnight. During deep sleep, it consolidates memories, processes emotions, and clears out metabolic waste via the glymphatic system — a kind of night-time rinse cycle for the brain. Lack of sustained quality sleep leads to slower thinking, difficulty concentrating, and reduced recall. Learning new skills or retaining information is harder when sleep is disrupted.

In one study, participants deprived of just one night of sleep performed significantly worse on tasks requiring decision-making and attention. Over time, this can contribute to cognitive decline and brain fog.

📚 Reference: Walker MP. The Role of Sleep in Cognition and Emotion. Ann N Y Acad Sci. 2009 Mar;1156:168–97.
PMID: 19338508

#4 Sleep Is Essential for Cardiovascular Health

During sleep, your blood pressure lowers and your heart rate slows — providing essential downtime for your cardiovascular system. When sleep is cut short or disturbed, your body remains in a more ‘switched on’ state, raising stress hormones such as cortisol. This leads to higher blood pressure, increased inflammation and greater risk of heart disease.

In fact, some research shows that regularly sleeping fewer than six hours per night increases the risk of heart attack, stroke, and irregular rhythms — independent of other risk factors. Prioritising sleep is one of the most effective ways to protect your heart.

📚 Reference: Cappuccio FP, et al. Sleep duration and all-cause mortality: a systematic review and meta-analysis of prospective studies. Sleep. 2010 May;33(5):585–92.
PMID: 20469800

#5 It Strengthens Your Immune System

Your immune system undergoes repair and reinforcement while you sleep. During the deeper stages of sleep, the body produces and releases cytokines — proteins needed to fight off inflammation and infection. Sleep also supports the production of white blood cells and impacts how the immune system responds to vaccines.

Chronic sleep deprivation has been shown to lower immune defence, making you more vulnerable to viruses, slower to recover and less responsive to vaccines. Even a few nights of poor sleep can suppress immune markers.

📚 Reference: Besedovsky L, et al. Sleep and immune function. Pflugers Arch. 2012 Jan;463(1):121–37.
PMID: 22071480

Most people need between 7–9 hours of sleep per night, but quality matters just as much as duration. Try going to bed and waking up at the same time each day, reducing caffeine after midday, dimming lights in the evening, and keeping screens out of the bedroom.

Remember, consistent sleep is not something to squeeze in when everything else is done — it’s the foundation that makes everything else possible.

With love and great health

Dr Lucy and Dr Mary XX 
 

Dr Mary Barson and Dr Lucy are the founders of Real Life Medicine. They help women who have been on every diet under the sun, optimise their health and achieve long lasting weight loss without feeling miserable or deprived.

They do this with their 3 step framework that

• Improves metabolism
• Develops mindset skills
• Provides tools to implement it easily into busy lives

With this comes increased energy, vitality and confidence.

You can avoid chronic disease and stop living life on the sidelines!