SNICKERS might like to think you are not yourself when you are hungry, but it turns out that may not be the case.

Well, that’s if you believe the increasing number of Silicon Valley execs taking the trend of intermittent fasting for weight loss to extremes — all in the name of performance.

Intermittent fasting allows followers to eat normally for five days a week and “fast” by limiting their intake to 500 calories for the other two days.

While popular among those looking to shed extra kilos, Silicon Valley exec Phil Libin has been fasting for anywhere between two and eight days to increase his quality of life.

Consuming just water, coffee and black tea during these fasting periods might sound like it does the opposite, but those using the technique swear otherwise.

In addition to the benefit of weight loss — Mr Libin has shed 40 kilos in eight months — the AI studio chief executive claims he has experienced fewer mood swings and improved productivity when fasting for extended periods.

“There’s a mild euphoria. I’m in a much better mood, my focus is better, and there’s a constant supply of energy. I just feel a lot healthier. It’s helping me be a better CEO,” he told The Guardian.

Achievement unlocked: first time since high school that I weigh less than 200 lbs. Five months of intermittent fasting experiments, -56lbs. pic.twitter.com/h0FsiJXTzp — Phil Libin (@plibin) February 4, 2017

“Getting into fasting is definitely one of the top two or three most important things I’ve done in my life.”

Mr Libin said he had his doubts when he first heard of the concept, but was willing to give it a try and was glad he did.

“The first day I felt so hungry I was going to die. The second day I was starving. But I woke up on the third day feeling better than I had in 20 years,” he said.

Chief executive of biohacking and nootropics company HVMN Geoffrey Woo said participants got the most out of the trend when combining fasting with tracking of vitals like body composition, blood glucose and ketones — a compound produced when the body burns fat for energy or fuel.

“You would think that after seven days of not eating you would be totally distracted and hunting for food, but at around the two or three day mark hunger tapers off as ketone levels are elevating. You are feeding your brain and body with an alternative fuel source.”

Mr Woo added ketones are a super-fuel for the brain.

“So a lot of the subjective benefits to fasting, including mental clarity, are down to the rise in ketones in the system,” he said.

But nutritionists warn that fasting could be detrimental to our health long term, encourage disordered eating habits or exacerbate pre-existing conditions including diabetes or anxiety.

“Muscle breakdown accounts for quite a bit of the weightloss in fasting diets, rather than fat,” dietitian Jo Travers told The Independent.