Ramadan-style dawn-to-sunset fasting: What the science says (and how to do it safely)

What the research suggests 

1) Metabolic health can improve—even when weight loss is modest

Across systematic reviews and meta-analyses, Ramadan fasting is often associated with small-to-moderate improvements in metabolic markers such as waist circumference, blood pressure, triglycerides and fasting glucose in many (but not all) groups. Results vary depending on baseline health, diet quality, sleep, and activity. (Jahrami et al., 2022; Osman, Haldar and Henry, 2020)

A key takeaway for patients: The scale isn’t the only measure of benefit. Some people see metabolic improvements even if their weight doesn’t change dramatically.

2) Inflammation markers may shift in a favourable direction

Inflammation isn’t inherently “bad”—it’s part of immune function. But chronically elevated inflammatory signals can be associated with long-term metabolic risk.

One human study measured inflammatory cytokines and immune cells before, during and after Ramadan fasting and found reductions in several pro-inflammatory markers in healthy participants. (Faris et al., 2012)

What this means practically: Fasting may nudge the immune–metabolic system toward a calmer baseline in some people—but it’s not a guarantee, and it doesn’t replace the fundamentals (sleep, diet quality, movement, stress support).

3) “Cell clean-up” (autophagy) is plausible—and now being measured in people

Autophagy is your cells’ way of recycling old or damaged parts and helping maintain cellular housekeeping. A lot of early work is from animal models, but human research is growing.

In one study, people who fasted during Ramadan showed measurable changes in the body’s “cell clean-up” system (autophagy). Some of the genes that help start this process became more active, and the effect appeared stronger in women for one of the markers measured. (Dastghaib et al., 2025)

In another study of adults living with overweight or obesity, four weeks of dawn-to-dusk fasting was linked with increased activity in several genes involved in autophagy. (Bou Malhab et al., 2025)

Important nuance: These are biomarkers—they suggest activation of pathways, not a magic “anti-ageing switch.” They’re still meaningful, but they should be interpreted cautiously.

4) Fasting can influence gene pathways linked to oxidative stress and metabolism

Some studies have shown changes in the expression of genes involved in antioxidant defence and metabolic regulation during Ramadan fasting (particularly in participants with overweight/obesity). (Madkour et al., 2019)

It’s tempting to jump from “gene expression changed” to “disease prevented.” That leap is too big. But these studies do support a more grounded statement:

Meal timing + a daily fasting window can shift biological pathways that researchers associate with metabolic resilience.

5) Your body clock and meal timing matter—sometimes more than we realise

Human metabolism follows circadian rhythms. When we eat late at night, sleep poorly, and snack across long hours, it can push hormones and glucose regulation in an unfavourable direction.

Time-restricted eating research (outside Ramadan) suggests that earlier eating windows can improve insulin sensitivity and blood pressure even without weight loss. (Sutton et al., 2018)

Ramadan fasting isn’t always “early eating” (iftar can be late, and some people eat into the night), but it can still create a consistent daily pattern—and consistency is often a win for the body.

Why dates are traditionally used to break the fast

Breaking the fast gently matters—especially after many hours without food and drink.

Dates have a long cultural history as an iftar food, and nutritionally, they make sense:

• They provide a quick source of carbohydrates to gradually raise blood glucose.
• They offer potassium and magnesium (useful minerals when you’re rehydrating and re-feeding).
• They tend to be well tolerated by the stomach.

In research, several varieties of dates have been shown to have a relatively low to moderate glycaemic index, including in people with type 2 diabetes (in controlled settings). (Alkaabi et al., 2011)

Practical tip: For most people, 1–3 dates + water is a gentle start, followed by a balanced meal after a short pause. If you have diabetes, portion size and medication planning matter—see the safety section below.

How to try a dawn-to-sunset fast (without needing to do a full month)

If you’re curious (for spiritual reasons, cultural solidarity, or health exploration), you don’t need a long protocol.

A simple, cautious approach:

1) Start with a low-demand day

Choose a weekend or a lighter workday. Avoid starting on a day with heavy training, travel, or high heat exposure.

2) Build a steady pre-dawn meal (suhoor-style)

Aim for:

• Protein (eggs, Greek yoghurt, tofu, legumes)
• Fibre + slow carbs (oats, chia, whole grains, lentils)
• Healthy fats (olive oil, nuts, avocado)
• Salted foods or soup if appropriate for you (helps hydration retention)

3) Plan hydration for the non-fasting hours

Because the day is “dry,” hydration becomes a nighttime project:

• Sip water steadily after sunset
• Consider electrolytes if you’re prone to headaches/cramps (as appropriate for your health conditions)
• Limit very salty or very sugary foods late at night (they can worsen thirst)

4) Keep exercise light and strategic

During adaptation:

• Prefer walking, mobility, gentle cycling
• If training, many people feel best close to sunset (so they can hydrate soon after), or after the evening meal

5) Break the fast gently

A simple structure:

• Water
• 1–3 dates (or a small portion of fruit)
• Pause 5–10 minutes
• Then a balanced meal (protein + vegetables + slow carbs)

Who should get medical advice before fasting (and who may be advised not to)

Please take this section seriously—especially with dry fasting.

You should speak to a clinician before fasting if you have:

• Diabetes (type 1, type 2 on insulin, or type 2 on sulfonylureas), a history of hypoglycaemia, or poor glucose awareness
• Pregnancy or breastfeeding
• Chronic kidney disease, kidney stones, or recurrent dehydration
• Heart failure, recent cardiac events, unstable angina, or complex cardiovascular disease
• Eating disorder history (past or present)
• Adrenal insufficiency or conditions requiring steroid replacement
• Any condition where dehydration could be dangerous, or where medication timing must be precise

Clinical guidance exists specifically to help risk-stratify patients who wish to fast (for example, in cardiovascular disease and diabetes). (Akhtar et al., 2022; Hassanein et al., 2022) Pregnancy evidence is mixed and limited; if someone chooses to fast, it should be individualised and closely monitored. (Ong et al., 2023) Kidney disease evidence varies by severity and comorbidity—monitoring and individual risk assessment matter. (Bragazzi, 2014)

Red flags while fasting (stop and seek help):

• Fainting, confusion, chest pain, severe weakness
• Persistent vomiting
• Signs of significant dehydration (very dark urine, inability to pass urine, dizziness on standing that doesn’t settle)