Eating Less Is the Latest Silicon Valley Productivity Hack Fasting is an uncomplicated way to get more alert, not just skinnier.

As instances of obesity, diabetes, cancer and other chronic illnesses are on the rise, a subculture where eating less is prized can seem farfetched and against the grain. Silicon Valley is the home of farfetched ideas, and executives are finding greater mental clarity, concentration and resistance to disease through an age old practice -- fasting.

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There are benefits for weight loss, but almost all of the Silicon Valley executives and high performing entrepreneurs fast for the ease, simplicity and opportunity to optimize their mental performance.

Why entrepreneurs are putting down their forks.

There are many forms of fasting, though the most popular is called "intermittent fasting." A person eats normally for eight hours during the day and then does not eat during a 16-hour period. Although the scientific literature on healthy adults isn't robust, evidence on animals and the elderly show great benefits for this simple fasting technique.

Fasting is known to decrease the rates of neurodegenerative diseases like Alzheimer's, Parkinson's and Huntington's disease. Other studies suggest improved memory retention in fasting individuals through a brain chemical called brain-derived neurotrophic factor (BDNF).

Restricting the time we eat daily allows our body and brain to self-repair and "take out the garbage." This is one of the reasons our mental performance is enhanced by fasting. But fasting can also improve our long-term health. Numerous studies count reduced cardiovascular risk, improved resilience against cancer and reduced signs of aging as benefits of fasting.

Of course, many of the benefits of fasting come from ease and simplicity. Eating one or two fewer meals a day means spending less time doing the dishes, less time visiting restaurants and spending less money. This often translates to increased freedom when one isn't tethered to the ball and chain of food and restaurants.

Some might suggest a lifestyle that revolves around skipping meals is short-term and shortsighted, but as the evidence shows, it is not only more convenient, but healthier and more effective as well.

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Which fasting option is best?

There are many fasting options, depending on an individual's needs and wants. The standard "intermittent fasting" is one of the more popular, but there are a host of others. Some people follow these:

• One meal per day -- essentially fasting 22-23 hours and eating 1-2 hours

• Fasting one full day -- waking up one morning but not eating until the next morning

• Eating fewer calories -- eating below 500-600 calories for a few days in a row

• Extended day fasts -- three, five and even seven days of fasting

All of these have their own unique sensations and benefits. Even eating a super low-calorie diet a few days a week (rather than no food at all) can have anti-cancer benefits, and this lifestyle supports anti-aging according to researchers Valter Longo and Satchidananda Panda.

Many in Silicon Valley are even doing extended fasts where they go without food, caffeine or supplements of any kind for three full days! Although these extended day fasts might seem outside the realm of your capabilities, most people anecdotally recount feeling clearer mentally, more focused and more alert. After all, for most of human history we were hunter-gatherers with scarce access to food. Fasting is in our DNA.

For people with heart conditions or other illnesses, it is a good idea to consult a doctor and have some type of supervision before doing anything too drastic -- especially extended day fasts. Fasting is a form of stress and shouldn't be done recklessly.

For eager beginners, a good place to start is to skip breakfast, and eat no food until noon. See how you feel after skipping a meal, but don't be too quick to judge. It took about two weeks for my body and brain to adapt to the timing of food.

The tech-friendly Silicon Valley execs are even taking kindly to various apps that aid in fasting. According to Cam Secore, owner of tech review site All Power Moves, "as odd as it sounds, numerous tech enthusiasts utilize Kevin Rose's app called 'Zero' to track their fasting. It's free, it works, but it's most useful because it creates accountability."

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The simplest mental performance trick for entrepreneurs.

Being involved in the supplement business (specifically nootropics), it's hard to parse what is snake oil and what actually works. With fasting, there is no beneficiary except you. Those who decide to eat less food and do so during a smaller timeframe can see a tremendous upside in the form of greater mental clarity, increased concentration and long-term health benefits.

As many of the entrepreneurs and executives in Silicon Valley have found out, a simple fasting practice can optimize mental performance without costing a dime. It increases ease in their lives and improves their long-term health.