Ramadan and intermittent fasting

How the two compare

	Ramadan fasting	Intermittent fasting
What it is	A religious practice, one of the five pillars of Islam 1	A way of timing meals, usually for health or weight
When	Every day for a month, from dawn to sunset	A plan you choose, such as 16:8
Drinks	None during the fast, not even water	Water, black coffee and plain tea
Meals	Suhoor before dawn and iftar at sunset	Any meals inside your eating window
Length	Set by dawn and sunset where you live	Set by your plan

Because the Islamic calendar follows the moon, Ramadan moves about 11 days earlier each year, through every season. How long each fast lasts depends on where you live and the time of year: near the equator it stays around 13 to 14 hours, while far from it a summer Ramadan can mean fasts of 18 hours or more.

Staying hydrated between iftar and suhoor

With no water during the day, what you drink in the evening and before dawn matters most. Even mild dehydration brought more headaches, tiredness and low mood in one study ², and a thirst headache usually eased within half an hour of drinking water ³.

• Spread water through the evening, from iftar to suhoor, rather than drinking a lot at once.
• Go easy on very salty foods, which make you thirstier.
• Coffee and tea count towards your fluids ⁴. But if you usually drink a lot of caffeine, cutting down gradually beforehand may help: on the first day of Ramadan, more than half of 755 caffeine drinkers got a withdrawal headache, more often the more they usually had ⁵.

A balanced suhoor and iftar

Suhoor, the meal before dawn, has to carry you through the day. Protein helps you feel full ⁶, so build it around eggs, yoghurt, cheese, beans or lentils, with whole grains such as oats or wholegrain bread, fruit and vegetables, and plenty of water. At iftar, many people break the fast with water and dates before a main meal. Starting gently, then eating a balanced meal with protein and vegetables, is often more comfortable than one very large meal.

What the research shows about weight

An earlier review found the same: an average loss of about 1.24 kg, mostly regained within a few weeks. Its authors concluded that lasting weight loss needs lifestyle changes that continue after the month ⁸.

Diabetes and other health conditions

Fasting during Ramadan is obligatory for healthy Muslims from puberty, and people with some illnesses and serious medical conditions, including some people with diabetes, can be exempted ¹. Whether you should fast is a question for your doctor and, on the religious side, for a scholar you trust.

If you have diabetes, the International Diabetes Federation and the Diabetes and Ramadan International Alliance publish practical guidelines for people who choose to fast and their care teams, including type 1 diabetes, older age, pregnancy and mental wellbeing ¹. Talk to your care team well before Ramadan: medication doses and timing often need changing, especially insulin and other medication that lowers blood sugar ⁹. See also medication while fasting.

Using Fasting Tracker during Ramadan

Fasting Tracker isn't a religious app. It doesn't show prayer, dawn or sunset times, and it can't tell you when to fast. If you'd like to time your fasts, you set the times yourself: start the timer at the end of suhoor and end the fast at iftar, or, with Pro, set a custom fast of 12 to 72 hours to match the day. If you forget, edit the start time or log a past fast. Between iftar and suhoor, log water towards your daily goal. The app's stages describe a fast with water, so treat them as a rough guide.

Sources

1. Hassanein M, Afandi B, Yakoob Ahmedani M, et al. Diabetes and Ramadan: Practical guidelines 2021. Diabetes Res Clin Pract. 2022;185:109185. doi.org/10.1016/j.diabres.2021.109185
2. Armstrong LE, Ganio MS, Casa DJ, et al. Mild dehydration affects mood in healthy young women. J Nutr. 2012;142(2):382-8. doi.org/10.3945/jn.111.142000
3. Blau JN, Kell CA, Sperling JM. Water-deprivation headache: a new headache with two variants. Headache. 2004;44(1):79-83. doi.org/10.1111/j.1526-4610.2004.04014.x
4. Killer SC, Blannin AK, Jeukendrup AE. No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS One. 2014;9(1):e84154. doi.org/10.1371/journal.pone.0084154
5. Magdy R, El Desouky ED, Hammad EM, et al. Prevalence, characteristics, and factors associated with caffeine-withdrawal headache during the first day of Ramadan. Headache. 2023;63(3):360-367. doi.org/10.1111/head.14483
6. Leidy HJ, Clifton PM, Astrup A, et al. The role of protein in weight loss and maintenance. Am J Clin Nutr. 2015;101(6):1320S-1329S. doi.org/10.3945/ajcn.114.084038
7. Fernando HA, Zibellini J, Harris RA, et al. Effect of Ramadan Fasting on Weight and Body Composition in Healthy Non-Athlete Adults: A Systematic Review and Meta-Analysis. Nutrients. 2019;11(2):478. doi.org/10.3390/nu11020478
8. Sadeghirad B, Motaghipisheh S, Kolahdooz F, et al. Islamic fasting and weight loss: a systematic review and meta-analysis. Public Health Nutr. 2014;17(2):396-406. doi.org/10.1017/S1368980012005046
9. Grajower MM, Horne BD. Clinical Management of Intermittent Fasting in Patients with Diabetes Mellitus. Nutrients. 2019;11(4):873. doi.org/10.3390/nu11040873
10. Glazier JD, Hayes DJL, Hussain S, et al. The effect of Ramadan fasting during pregnancy on perinatal outcomes: a systematic review and meta-analysis. BMC Pregnancy Childbirth. 2018;18(1):421. doi.org/10.1186/s12884-018-2048-y