Author: Nasha Solim, Pharmacist and Author of “The Shadow of my Ancestral Tree”

Fasting during Ramadan is more than feeling hungry; it is a biological reset that almost 2 billion people benefit from annually. Science now affirms what the religion has prescribed for many years: fasting rejuvenates the body, sharpens the mind, and strengthens the spirit (Sinclair, 2020; Mizushima & Levine, 2018). With more people of all faiths—and none— becoming interested in fasting and its health benefits, this blog post will explore its medical advantages.

What Happens in Your Body When You Fast?

Here’s a simple timeline of what happens when you fast:

  • 0-4 hours after suhoor (pre-dawn meal): Your body runs on glucose (sugar) from your last meal and insulin (a key that unlocks cells to use sugar for energy) levels remain stable (Salti et al., 2004).
  • 4-12 hours: Your glycogen (stored sugar) begins to run out, so your body switches to burning fat for energy. At the same time insulin sensitivity improves, helping with blood sugar control (Patrick, 2019).
  • 12-16 hours: Ketones become your primary energy source. This activates autophagy; your body’s way of detoxing and recycling damaged cells (Sinclair, 2020).
  • After iftar (breaking fast): A well-balanced meal replenishes energy levels. Your metabolism becomes more flexible helping with long-term health benefits (Jalali et al., 2022).

A Four-Week Transformation

Fasting comes with initial challenges like headaches, fatigue and irritability but your body adapts quickly in interesting ways, leading to increased energy, better focus, and emotional balance by the end of Ramadan.

  • Week 1: Headaches and fatigue occur as your body shifts from sugar to fat for energy. Caffeine withdrawal and dehydration can worsen symptoms (Salti et al., 2004; Wilson et al., 2020). Your body learns to use fat for fuel, reducing insulin levels and enhancing metabolic flexibility (Patrick, 2019).
  • Week 2: Inflammation decreases, oxidative stress lowers and growth hormones rise, helping to preserve muscle (Jalali et al., 2022). Energy stabilises as insulin sensitivity improves. Mental clarity increases due to higher brain-derived neurotrophic factor (BDNF) levels (Jalali et al., 2022; Mattson et al., 2017).
  • Week 3: Autophagy (the body’s way of cleaning out damaged cells) reaches its peak, helping to slow aging and reduce disease risk, improving mental clarity and stabilising emotions. Hunger declines as the ghrelin hormone decreases (Mizushima & Levine, 2018).
  • Week 4: Your metabolism is optimised, leading to improved heart health, brain function and insulin sensitivity (Al-Masri et al., 2022). Metabolism becomes more flexible, reducing energy crashes. Cortisol (stress hormone) lowers, enhancing emotional resilience and well-being (Koenig, 2012).

The Science-Backed Benefits of Fasting

Contrary to popular belief, fasting is not just about weight loss; it has deep, long-lasting effects on nearly every system in the body.

1. Cellular Cleansing & Longevity

Fasting activates autophagy, a process where your body removes damaged cells and regenerates new ones. This is linked to slower aging, better brain health and a reduced risk of neurodegenerative diseases (Mizushima & Levine, 2018).

2. Blood Sugar Control & Diabetes Prevention

Over time, overeating can make your body less responsive to insulin, increasing the risk of type 2 diabetes, especially in Black African, African Caribbean and South Asian communities. Fasting helps improve insulin function, lower blood sugar levels, reverses early-stage insulin resistance and reduces the risk of type 2 diabetes (Salti et al., 2004; Zauner et al., 2022).

3. Heart Health & Reduced Inflammation

Fasting lowers blood pressure, bad cholesterol (LDL) and triglycerides while reducing inflammation markers linked to heart disease (Tayeb et al., 2019; Yazdi et al., 2021). These changes can reduce the risk of chronic diseases like heart disease and stroke.

4. Cancer Prevention & DNA Repair

Studies show that fasting reduces inflammatory markers like TNF-alpha and IL-6, which are linked to chronic diseases. It also enhances DNA repair, reduces oxidative stress (where there are too many harmful molecules called free radicals in your body and not
enough antioxidants to neutralise them) and decreases insulin-like growth factor 1 (IGF-1), a hormone associated with cancer growth (Al-Masri et al., 2022; Mizushima & Levine, 2018; Zauner et al., 2022).

5. Gut Health & Digestion

Fasting gives your digestive system a break, allowing the gut lining to repair itself. It promotes the growth of good gut bacteria while reducing inflammation linked to conditions like irritable bowel syndrome (IBS) and leaky gut (Cani et al., 2019; Paoli et al., 2019).
6. Mental Health & Emotional Well-Being
Fasting isn’t just good for the body, it is great for the mind. It boosts serotonin and dopamine (the “feel good” neurotransmitters), lowers stress hormone cortisol and supports brain function by increasing brain-derived neurotrophic factor (BDNF), which helps with learning and memory (Koenig, 2012; Mattson et al., 2017).

7. Weight Loss & Metabolism

Unlike restrictive diets that slow down your metabolism, fasting preserves muscle while burning fat. It reduces the hunger hormone ghrelin, boosts fat burning and increases growth hormone production, making weight loss more sustainable (Varady et al., 2020; Heilbronn et al., 2005).

8. Spirituality, Community & Mental Strength

Fasting during Ramadan is not isolated to not eating, with people coming together to break their fast, fasting can strengthen bonds with family and community. Other suggested activities during Ramadan like sharing meals, giving to charity and practicing gratitude increase serotonin levels, reinforcing mental and emotional well-being (Holt-Lunstad et al., 2010; Koenig, 2012).

Fasting: A Natural Reset

Fasting is not about deprivation; it is about restoration as you are not just nourishing your soul but healing your body too. So, this Ramadan whilst you look forward to kebab rolls at iftar and your new dress to wear on Eid, remember the incredible health benefits that come ٱلْ َع ِلي ُم).( with the sacred practice of fasting, for Allah is All-Knowing-Al Aleem

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