From the 5:2 diet to a 24-hour fast, and even Rishi Sunak’s 36 hours of abstinence, almost everyone has had a brush with intermittent fasting (IF).
It has many forms, and has recently exploded in popularity as people learn about some of the benefits IF can have. But every year, millions of Muslims around the world undertake a month of a different form of intermittent fasting – known widely as Ramadan.
During this period, Muslims are not permitted to have any food or water during sunlight hours and have two main meals a day, known as Suhoor and Iftar.
But what effect can IF have on a person’s body, and is it something you should try?
What effect does intermittent fasting have on your body?
‘Intermittent fasting has gained significant popularity as a dietary approach,’ dietician Jenaed Brodell, founder of Nutriton and Co, tells Metro.co.uk.
‘But it’s essential to approach it with caution, especially for those in certain populations such as pregnant or breastfeeding individuals, people with diabetes, and those with a history of eating disorders. Consulting with a healthcare professional before starting any fasting regimen is recommended to ensure it aligns with individual health needs and goals.’
Ms Brodell says that IF, for the right person, can assist in weight loss, through regulating calorie intake and could improve metabolic health – as well as having potential longevity effects such as increasing lifespan and preventing age-related diseases.
But when it comes to Ramadan, UCL doctoral researcher Alex Ruani says that by doing this form of fasting ‘right’, such as eating healthy and not compromising sleep, there could be a myriad of benefits.
‘Ramadan fasting has shown many favourable cardiometabolic effects in healthy people, including lower blood levels of LDL ‘bad’ cholesterol, triglycerides, fasting blood glucose, inflammatory markers, and oxidative stress markers,’ she tells Metro.co.uk.
‘Other benefits seen are improved gut microbiota composition, better liver function and an improved modulation of genes linked to antioxidant defence.’
However, just because you’re fasting for over 12 hours, does not mean you’re guaranteed to lose weight. There is something known as the Ramadan paradox, where people often put on weight despite fasting all day.
‘Depending on what, how much, and how long you gorge overnight, your fast may turn into an unhealthy feast in disguise,’ says Ms Ruani.
‘To avoid turning your fast into an unhealthy feast negating its benefits, it helps to eat a variety of fruits, vegetables and legumes while timing your meals, rather than eating for an unlimited time, which can also rob hours from your sleep.
‘We know that sleep deprivation can result in increased levels of the hunger-inducing hormone ghrelin, making us ravenous and more likely to overindulge during the night-time eating window.’
During the month, people often increase the amount of sugar they eat, which could lead to an increase in weight, and if that’s coupled with non-stop night-time binging, poor food choices and reduced physical exertion with fewer calories spent, you won’t feel any benefit at all.
Ms Brodell agrees, and says intermittent fasting can also have a few negatives, which could lead to potential nutrient deficiencies.
‘Limited eating windows may make it challenging to consume adequate nutrients, particularly if not carefully planned,’ she says.
And for some people, being hangry is a real thing: ‘Some people may experience fatigue, irritability or decreased focus during fasting periods, impacting daily activities.’
Ramadan: the lowdown
- Ramadan falls in the ninth month of the Islamic calendar and is the time when Muslims dry fast during daylight hours
- It lasts around 29/30 days, and begins when the Moon is in its crescent form – and usually moves back 11 days in the Gregorian calendar
- This month is considered to be holy as it’s believed to be when the Qur’an was revealed to Prophet Muhammad
- Dates are traditionally eaten first thing for Iftar
- People travelling further than 50 miles could be exempt from fasting
- People who are pregnant, on their period or have certain illnesses like diabetes are also exempt
- Ramadan is more than just avoiding food, and there are other restrictions such as having sex during fasting hours
Ms Ruani says that another contributing factor to weight gain while fasting could be due to the leptin rhythm – a body cycle that helps regulate the long-term balance between your body’s food intake and energy use.
‘Going against leptin’s rhythm from eating most calories during night hours is one of them,’ she says. ‘This may disrupt your metabolism and make you pile on the pounds, especially in the first two weeks. After that, leptin rhythms start shifting and become adapted to a later eating time.
‘As leptin levels become higher in the morning instead of night-time, we may experience enhanced fullness throughout the day helping us to better maintain the fast.’
Ramadan is a well-known intermittent fast, but when stacked against the alternatives, Ms Ruani says other methods produce more pronounced fat loss and body composition advantages.
Other types of intermittent fasting often show weight loss that is less fleeting and more lasting than Ramadan fasting.
Either way, it’s important to only intermittently fast when it’s something you can handle – as even Ramadan fasting is exempt for individuals with medical conditions like severe diabetes, heart disease and kidney disease.
It’s also exempt for pregnant or breastfeeding women, as well as those hospitalised, prescribed oral medication during fasting hours, or for whom fasting could pose a health risk.
But as we inch closer and closer to Ramadan, millions of people are preparing to dry fast in daylight hours, and for the next 30 days, their relationship with food dramatically changes.
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