Everything you need to know about intermittent fasting

With more people turning to intermittent fasting to channel a sense of well-being, we weigh in on the benefits of sporadic eating

Nutritionists recommend eating fibre-rich fruits, veggies, wholegrains and lean plant proteins when fasting intermittently. Getty

Earlier this week, Twitter co-founder Jack Dorsey put out a question to his nearly 4.2 million followers. "Been playing with fasting for some time," he tweeted. "I do a 22-hour fast daily (dinner only), and did a 3-day water fast. Biggest thing I notice is how much time slows down. The day feels so much longer when not broken up by breakfast / lunch / dinner. Anyone else have this experience?"

The Twitterati were quick to like, retweet and respond to Dorsey’s query. Amid the rabble-rousers and comics, one of whom requested “can we get an edit button before you pass out?”, many users shared their own experiences with intermittent fasting, with some noting they had lost weight and felt more mindful, while others deemed it an unhealthy fad.

Fasting in fits and starts

Intermittent fasting can follow two formats: either you fast for a number of hours per day or a number of days per week.

Dr Charushila Thadani, director of health services at Aetna International, lists some common intermittent-fasting methods. “The 5:2 method allows you to eat normally five days a week. The other two days are your fasting days, although you can still eat; just keep it between 500 and 600 calories.

“With the eat-stop-eat method, you restrict all food for 24 hours, once or twice a week. In 16/8, you eat all your daily calories within a shortened period, typically 6 to 8 hours, and fast for the remaining; you can do this every day, or a few times a week. And in alternate-day fasting, you fast every other day, with some eating about 500 calories on fasting days.”

Of course, some add their own permutations to these formulae, such as eating only one meal every day – a la Dorsey. “Intermittent fasting is popular among the ‘life-hacking’ crowd, as it can improve your health while simplifying your life – you don’t need to plan, cook or clean up after as many meals as before,” adds Thadani.

"With 5:2, you limit your intake, but some load up on black coffee, tea or diet drinks to get them through the day, which is not healthy at all," she cautions. "Also, on non-fasting days, no matter which regime you are following, you are supposed to follow a healthy eating programme, but the temptation can be to eat anything and as much as you want.The theory is that by restricting calories on a number of days in the week or hours in a day, you can lose weight, and reduce blood sugar and ­cholesterol. However, scientifically it's not known yet which regime works best. Most studies have been conducted on small groups over short time periods," notes British nutritionist Dr Marilyn Glenville.

Pros and pitfalls

A team at the University of Texas recently conducted a study on intermittent fasting, and found that going through periods with little or no food – what they call time-restricted fasting – reduces inflammation, improves blood lipids and helps in weight loss. Notably, the participants did not reduce their total number of calories – just the time frame in which they consumed them.

“During fasting, cells are put in stress and this can help to lose weight as fat is used as a source of energy. This helps to maintain the blood sugar and cholesterol levels,” says clinical dietician Archana Baju from Burjeel Hospital, Abu Dhabi.

"If you are fasting, include fibre-rich fruits, veggies, wholegrains, lean and plant proteins in your diet, and stay hydrated. Avoid carbonated beverages, junk foods, refined carbohydrates, calorie-dense sweets and fried foods." She adds that such a diet is not sustainable or recommended in the long term, a viewpoint countered by Saliha Afridi, clinical ­psychologist and managing director of The LightHouse Centre for Wellbeing.

"We as a society eat too much, and we mainly eat out of habit and not out of hunger. I have been doing IMF since I was very young. I prefer to eat one meal a day and snack in the afternoon. I have people tell me: 'You do not look like you are a mother of four ­children, or that you are in your 40s,' and I believe it is because of IMF – giving my organs rest so they can recuperate."

Ruba Elhourani, head dietician at RAK Hospital, says weight gain is a major disadvantage for those who fall off the intermittent-fasting wagon. “When people who are used to a limited amount of calories go back to a regular diet, it has an adverse reaction and they can regain the weight lost. There’s also the possibility of extra weight gain since they may consume certain foods that they were deprived of. Moreover, such type of fasting [can] lead to dehydration.”

Intermittent ­fasting is also unsuitable for people who have diabetes, or are under 18 and still growing, as well as for women who are pregnant or breast feeding.

“Some studies demonstrate that intermittent fasting may cause adverse effects such as low moods, fatigue, reduced concentration, and disruption in the menstrual cycle,” says Azza Al Jneibi, a nutritionist at Cleveland Clinic Abu Dhabi. “We recommend medical consultation for those who have a history of eating disorders, have been diagnosed with type 1 or type 2 diabetes, are underweight, malnourished or have nutritional deficiencies, before they begin this form of dieting,” she adds.

“This kind of diet is harder for women because they are more susceptible to blood sugar fluctuations, which can be ­exacerbated depending on which part of the menstrual cycle you are in,” says Glenville. “My major concern is that this type of fast doesn’t re-establish a healthy relationship with food for most, which is really the ultimate goal for serial dieters.”

Cultural connotations

Trend it might be, but fasting has been practised by some cultures regularly. Following Dorsey’s tweet, some users referenced Islam, pointing out that Muslims have been fasting intermittently for centuries, especially during Ramadan. And the majority of adults who stick to healthy and nourishing food during the Holy Month report losing weight and an enhanced sense of well-being.

Afridi urges naysayers to look past politics and dogma to ­consider the healing power of religion and traditions. “There are many things that ­individuals do to attain a higher level of spirituality, fasting being one of them.” She lists three advantages she has experienced by fasting on a regular basis, as well as during Ramadan. “The first is connection with a higher power. When people are not thinking about their next meal, they have more time and less distractions. Denying the body [food] can result in more of a connection with the spirit.

“Second is heightened energy because, once you have gone through the initial detox, the body is not using [as much] energy for digestion.

“Finally, most individuals who engage in IMF say they feel clean and clear. Their stomach is not hurting from eating foods that are bad for them, they feel in control.”

Mind games

Like Dorsey, who felt the ­absence of a set time for ­breakfast, lunch and dinner, Twitter user Anthony Noto said time did slow down when he fasted, “mostly because I am fighting the hunger [pangs] and watching the clock ­counting down until I can eat”.

Afridi admits the day is likely to feel longer when you first start fasting because of long-­ingrained eating habits, but that it gets easier as the weeks go by.

“Most people I know, including myself, who do IMF skip breakfast, and ‘break their fast’ at 3pm or 4pm with fruit or a snack, and then eat dinner at 8pm. That’s about an 18-hour fast most days. Once your body adapts to this routine, it actually ­becomes a way of life.

“To counter the struggle, do something fun that keeps you engaged during those set times where you used to eat. You should also drink electrolytes so you don’t feel weak. Sometimes we eat not because we are hungry, but ­because we want to take a break from work or to ­socialise. Find other ways that you can have those needs met, and you will soon be able to break the habit of eating on external cues.”  

Above all, she says, fast healthy. “When you start ­intermittent fasting and stay away from sugar and processed foods, you do not crave them after some time. Eventually, the addiction of eating these foods wanes and being healthy becomes a way of being rather than something you only do for a specified period.”