To those of us who struggle to make it past 11am without eating their lunch may find it hard to comprehend the lives of a group of Silocon Valley entreprenuers (who else?) who regularly fast for at least 36 hours.The WeFast group argues that by only drink water for 36-hours in a row, they are more focused mentally and have boost their health.

The “MonkFast” regime which they adhere to involves ending the first day with a typical dinner, then fasting for an entire day, and eating in the morning of the following day.

The WeFast website warns those tempted by the regime that they will drink more water than usual, feel colder as the body begins to conserve energy, and experience hunger pangs that are best dealt with by "keep[ing] yourself busy." Other fasting protocols followed by the group include "Leangains", where a person fasts for around 15 hours; the "Warrior Diet" 20-hour fast followed by a large evening meal; and "The Himalayan Fast" for 60-hours straight.

"Most people think that my regimen is crazy and that it is impossiblem”, Geoffrey Woo CEO and co-founder, of Nootrobox supplements, told The Independent, but urges that it is “100 per cent safe."

"I'm currently doing a seven day or 168 hour fast to start off the New Year with most of my company and with over 100 of our community members.

The world's biggest food fights Show all 11 1 /11 The world's biggest food fights The world's biggest food fights La Tomatina, Buñol, Spain Revellers throw tomato pulp at each other during the annual "tomatina" festivities in the village of Bunol, near Valencia on August 26, 2015. Some 22,000 revellers hurled 150 tonnes of squashed tomatoes at each other drenching the streets in red in a gigantic Spanish food fight marking the 70th annual "Tomatina" battle. AFP PHOTO / BIEL ALINO (Photo credit should read BIEL ALINO/AFP/Getty Images) Biel Alino/AFP/Getty Images The world's biggest food fights La Tomatina, Buñol, Spain A reveller is pelted with tomato pulp during the annual "tomatina" festivities in the village of Bunol, near Valencia on August 31, 2016. Today at the annual Tomatina fiesta 160 tonnes of ripe tomatoes were offloaded from trucks into a crowd of 22,000 half-naked revellers who packed the streets of Bunol for an hour-long battle. / AFP / BIEL ALINO (Photo credit should read BIEL ALINO/AFP/Getty Images) Biel Alino/AFP/Getty Images The world's biggest food fights La Tomatina, Buñol, Spain Revellers covered in tomato pulp participate in the annual "tomatina" festivities in the village of Bunol, near Valencia on August 31, 2016. Today at the annual Tomatina fiesta 160 tonnes of ripe tomatoes were offloaded from trucks into a crowd of 22,000 half-naked revellers who packed the streets of Bunol for an hour-long battle. / AFP / BIEL ALINO (Photo credit should read BIEL ALINO/AFP/Getty Images) Biel Alino/AFP/Getty Images The world's biggest food fights World Custard Pie Championship, Kent Funk Dooby/Flickr The world's biggest food fights World Custard Pie Championship, Kent Funk Dooby/Flickr The world's biggest food fights La Merengada, Vilanova i la Geltrú, Spain Ajuntament de Vilanova i la Geltrú The world's biggest food fights La Merengada, Vilanova i la Geltrú, Spain Ajuntament de Vilanova i la Geltrú The world's biggest food fights Battle of the Oranges, Ivrea, Italy Giuseppe Cacace/AFP/Getty Images The world's biggest food fights Battle of the Oranges, Ivrea, Italy Giuseppe Cacace/AFP/Getty Images The world's biggest food fights Clean Monday, Galaxidi, Greece Louisa Gouliamaki/AFP/Getty Images The world's biggest food fights Clean Monday, Galaxidi, Greece Louisa Gouliamaki/AFP/Getty Images

In 2016, Woo fasted for between 44 to 48 weeks of the year, only stopping while he was travelling or on holiday.

“I think my health, energy, and biometric data shows that this is not crazy. It's very possible, and in fact a lot more optimal. We have thousands of people in our community fasting with us on a weekly basis.

WeFasters point to evidence that cutting out food can lead to a longer life; boost the metabolism; improve immunity; and cut the risk of cancer.

“Our bodies have a natural refrigerator of energy in body fat. We evolved as a species to have a second metabolism mode, or ketosis, where we use fat for energy rather than carbs or glucose or glycolysis," he explains.

“When we fast, we dip into this mode of tapping our own fat for energy. You can think of it like 'turbo' mode for survival and it's more efficient for our cells.”

Nootrobox founders Geoffrey Woo and Michael Brandt fast for at least 36 hours a week (Nootrobox)

In fact, he believes fasting is important in desensitising ourselves to advertising and the culture which tells us to eat all the time.

“That's why we see the highest obesity rates in the history of humanity. Let's solve this massive societal problem with fasting and other biohacking.”

“Biohacking is a populist movement within today's broken healthcare system. USA has some of the highest healthcare costs with some of the worst outcomes. Optimising what we intake on a daily basis is often much more impactful than an annual check-in with an overworked doctor who sees you for 15 minutes.

Woo said the team settled at 36 hours because the body stores excess glucose in the liver as glycogen for between 20 to 24 hours.

“Once we deplete glycogen, our bodies start process called autophagy, which recycles damaged senescent cells. Our bodies also start releasing natural human growth hormone and brain-derived neutrophic factor that promote new neurons and healthy lean muscle mass.”

“We all have access to ketosis. Our ancestors have survived famines much worse than not eating for 36 hours. We all have the ability to fast; it's just that the vast majority of us have never used it.”

The WeFast group meets every Wednesday in San Francisco to end their water fast (Nootrobox)

Woo admits that it was tough at first, but that overcoming his urges was "mentally and physically liberating."

"My body was tuned to expect the next snack and the next insulin spike because our society is trained and programmed for constant consumption."

By the third run, he said it became “refreshing” and something he looked forward to. Still, Woo isn’t as invincible as he sounds.

“I love great food, and I'm the type of person that will invest in Michelin starred restaurants. I don't feel hunger pangs, but the idea of delicious food is attractive. Sushi, BBQ, pho, and hot stews sound tempting right now.

“The first time I tried to do an extended fast of five days I timed it to break on Thanksgiving. I failed in the middle. I didn't have the discipline to continue at one AM at night, so I ate a protein bar and then had a lot of delicious food the next day to reset and recalibrate to complete another two days of fasting."

To break his fast, Woo, a high fat, medium protein, low carb ketogenic breakfast with eggs, bacon, avocado, greens like spinach. For lunch he will eat a large salmon or chicken salad.

“Because I'm disciplined with fasts, I'll let myself eat whatever comes to fancy and is convenient for subsequent meals.”

And he stresses that fasting isn't for everyone. Those who are underweight certainly shouldn't try his regime.

Building on this, Gillian Killiner a British Dietetic Association spokesperson who runs 121Dietitian.com, commented that fasting can be approached in many different ways, including the popular 5:2 diet. However she stresses that fasting must be adopted gradually and care must be taken to eat well afterwards.

“Repeatedly fasting and not replenishing the body can cause negative issues if not careful.”

People who have mental health issues, such as body dysmorphic, anorexic, shouldn’t fast, she adds. “Certain groups with heart failure, kidney and so on would really not wish to do anything drastic but actually try to eat healthy and exercise and stay within the parameters of their optimal health. If they are already within this then they should discuss any changes with their physician and dietitian.”

In fact, she argues, fasting and depriving oneself of food is a privilege.

“Overall, if you are able to make a few changes in looking after your health and wellbeing physically and mentally and enjoying the world fully, then wow, how fortunate we are to have the privilege that many do not.”