The FastDay Forum

Some muslims fast (all year) from dawn to dusk on Mondays and Thursdays (or Tuesdays and Thursdays). Once again, from dawn to dusk, and then no limit for what they eat between dusk and dawn.

How does this compare health wise and practicality wise to the 5-2 diet? In my mind, the Islamic fast might be easier to handle, because once dusk sets in, you are no longer constricted by calories intake, unlike the 5-2 which severely restricts your normal intake.

Has there been research on this Islamic fast, which not many non muslims are aware of?

Ghost in Saudi

Research seems to be centered around Ramadan fasting, not what you mention which is effectively 5:2 as a maintenance strategy when calorie restriction is not required.
It should work really well, but better in the countries with a larger gap between dawn and dusk, like UK in the summer. Eating-window strategies seem to suggest at least 16 hours fasting, maybe optimum is 19 hours but this would be quite a restriction for every day...

[carorees]

There is also some research that show the changes in leptin and thyroid hormones during the daylight hours suggests that our bodies are better adapted to feeding during daylight rather than during darkness. This suggests that eating after dawn and before dusk is best. I would guess that as humans evolved in the tropical latitudes that at least a 12 hour overnight fast would be normal for our bodies.

As Pete says, all the research has been done on changes during Ramadan with many (most?) studies finding participants improve various health markers during Ramadan. I've seen nothing on the Monday/Thursday fasts. I think the research has been driven by the need to determine which groups of people should be given dispensation from observing Ramadan on health grounds rather than out of interest in the role of fasting for health.

However, as we don't know which fasting regimen is best for long-term health, I would say that it is likely that the Monday/Thursday dawn to dusk fast would be likely to be better than not fasting! However, if you really do feast as soon as the sun has set than the total calorie intake might not be any different from the other days of the week! The fact that the research on Ramadan has not always found an improvement in health markers may be due to how much and what kind of feasting the subjects indulged in when the fast was over each day.

If you decide to use this approach, I think you should try to eat sparingly to create some kind of calorie restriction (especially if you are hoping to lose weight).

Just wanted to add that although I am not familiar with this type of regular Muslim fasting, I have noticed quite a big change in Ramadan fasting over the last decades. When I first experienced it nearly 40 years ago, people broke the fast with water and a light soup, followed by a modest meal. The pre-dawn meal, if taken, was also very modest, usually bread and labeneh (a curd cheese). Feasting didn't begin until the holy month of Ramadan ended with the Eid. Nowadays, virtually every night between sunset and dawn is a marathon of eating celebration foods and drinking cokes etc. sweets and fruit until you're stuffed. Modern times eh?

As a regular 16:8er I would say that you need to be careful. You can pack a heck of a lot of calories into a short space of time if you are so minded! Still, I suppose its the same for 5:2. the people who do well are the ones who naturally cut back on the 5 off days. You only have to read the posts to see that anyone who normally eats a high calorie diet would struggle to lose if they just let it rip!

I believe its generally accepted that you need a minimum of 14 to 16 hours of fast to get any health benefits and that you should aim for at least 3 of those fasts a week. Whether there is any solid research to support this I couldn't say. Most research is animal based anyway so I guess we are the guinea pigs here!

As I understnad it any fasting you can achieve is all to the good.

What the 5;2 diet encourages is a full 2x24 hour period of fasting in any given week.

So, for me, usually, that means on rising at 7.00 am or whatever from day a........though till 7 am day b.