Intermittent fasting is a method of eating that essentially permits you to eat whatever you want (within reason) during a specific time period. Although the concept was created in the early 1900s as a treatment for epilepsy, it resurfaced as an effective weight loss tool in the mainstream around 2013 with the promotion of the 5:2 diet. The 5:2 diet allowed followers to eat unrestricted for 5 days, whilst restricting calories for the remaining 2 days of the week.
In 2018, the concept has taken on many forms, including fasting for extended hours during the day, to limiting intake to 500 calories per day.
Science, and logic to some extent, supports fasting's ability to help you lose weight, mostly due to a smaller window of time to eat, therefore more likely a reduced caloric intake.
However research has also linked the eating pattern to improved blood sugar levels, decreased risk of heart disease and cancer, and, according to neuroscientist Mark Mattson's research, it might just help your brain ward off neurogenerative diseases like Alzheimer's and Parkinson's while improving mood and memory say scientist in Neurobiology Of Disease.
But what about the gains? Surely eating less will mean that your body will turn to your hard-earned muscle mass for nourishment. Not exactly.
A recent 8 week long study on the effects of fasting on the muscle mass of active males, published in the Journal of Translational Medicine, found that only fat fell victim to the effects of the restriction.
"Our results suggest that an intermittent fasting program in which all calories are consumed in an 8-h window each day, in conjunction with resistance training, could improve some health-related biomarkers, decrease fat mass, and maintain muscle mass in resistance-trained males. Growth hormone has been shown to increase as much as five-fold in your blood as a result of fasting, helping you build muscle quicker, according to the Journal Of Clinical Investigation.
“The majority of studies have been on animals, and we need more research,” says Robin Foroutan, RDN, a spokesperson for the Academy of Nutrition and Dietetics when talking to Prevention. "But if you're in overall good health, it's probably safe to try it out."
One high profile fan of the eating plan is MH Action Hero, Tim Robards, who regularly fasts until 12pm. "Break-fast doesn't always have to happen as soon as you wake... lots of benefits to breaking fast a little later when coupled with a real food diet," said Robards on his Instagram profile, with wife Anna Robards (née Heinrich) also a devout follower.
"I’ve been doing a bit of intermittent fasting," she recently told Alex Davies of Women's Health. "So, I won’t get up and have breakfast straight away – I have it around 11am or 12pm, which I guess is lunch or brunch! I don’t do that every single day (some days I get up and am a lot hungrier than others) but when I do, I find I have just as much energy and can still tackle the day. Everyone’s individual so it’s about what works for you."