Intermittent fasting and Ramadan fasting are similar in that both involve periods of restricted food intake, but they differ in terms of duration, frequency, and religious observance.
Intermittent fasting typically involves restricting food intake for shorter periods, such as 16 hours of fasting (but water is allowed) followed by 8 hours of feeding, while Ramadan fasting involves a full day of food and water restriction from sunrise to sundown for one month.
Intermittent fasting strategies, including alternate-day fasting and time-restricted feeding, have been used as approaches to weight loss, although evidence for their efficacy is mixed. Please click here to read our full article about intermittent fasting.
Is fasting for longer hours more beneficial?
Benjamin Horne, director of cardiovascular and genetic epidemiology at Utah’s non-profit Intermountain Healthcare system says, “There’s some evidence that the longer you do a complete fast, the more benefit you get.” It may eventually turn out that longer periods of true fasting—say, going 24 hours or even several days without any food at all—could be even more beneficial.
Is fasting for longer duration more beneficial?
Research from Valter Longo, a professor of gerontology and director of the Longevity Institute at the University of Southern California, has found that fasting for four or five consecutive days a month may extend life and reduce disease risks1. But again, more human data is needed—especially when it comes to fasting’s effects on older or sick adults.
Fasting also makes sense from an evolutionary standpoint. All-the-time access to food is a relatively new phenomenon in human history. Back when sustenance was harder to come by, “natural selection would have favored individuals whose brains and bodies functioned well in a food-deprived state.”
Does the time of the day we fast and eat matters?
According to a recent study published on January 18, 2023, in the Journal of the American Heart Association, the time when you eat, in and of itself, doesn’t appear to be helpful for weight loss. What did matter was the size of the participant’s meals. People who ate more large- or medium-sized meals were more likely to gain weight, while people who ate small meals were more likely to lose weight. In the study, 547 participants used a phone application to track their daily meals over a six-month period.
Dr. Nisa Maruthur, an associate professor at Johns Hopkins School of Medicine, agrees. “If your calories are the same, regardless of when you eat them, there’s not an impact on weight,” says Maruthur.
Is lack of water intake injurious to health?
There is no strong evidence for direct injurious effects of dehydration on normal healthy adults. Caution is advised for certain individuals with chronic health conditions like chronic kidney disease or diabetes. According to one Indonesian study, the most common drinking pattern in Ramadan is 2-4-2, but a drinking pattern of 4-2-2 glasses (sequence of four glasses at iftar, two glasses at nighttime, two glasses at suhoor) had a significantly higher chance to adhere with the recommendation of fluid intake compared to other patterns.
Conclusion:
It appears that the effects of Ramadan fasting with longer hours and longer duration of days may have additive beneficial effects to what we have seen for intermittent fasting. It is important to consult a healthcare professional if someone has underlying medical conditions to ensure that fasting is right for them.