Silicon Valley's elite are flocking to an extreme high-fat diet in hopes of living longer

• Silicon Valley's investors are trying out ketogenic diets, which involves extreme carb restriction. Some are reporting rapid weight loss and better energy.
• Side-effects also include crankiness and bad breath.
• A venture-backed company is hoping to reverse type 2 diabetes with "nutritional ketosis."

A lot of the Silicon Valley elite are doing extreme experiments on their bodies in hopes of prolonging their lives and improving their health. The latest fad among this set is sticking to a so-called 'ketogenic' diet that's exceptionally high in fat and low in carbs and is considered an experimental treatment for diabetes. Think Atkins, but way more extreme.

Ambar Bhattacharyya, a managing director with Maverick Ventures, initially embarked on a low-carb, high-fat "ketogenic" diet during the due diligence process for a startup called Virta Health. The diet was designed to transition his body to burning fat as its primary fuel source, rather than glucose. Those on the diet typically eat less than 30 grams of carbs each day.

He lost about 7 pounds in the first week, but gave up after a few months. "I started to get really cranky and had to drink a lot of coffee," he recalled. "That meant a lot more bathroom breaks during our partner meeting."

Bhattacharyya said that two other investors at the office tried it, meaning about a third of the office was on ketogenic diets.

Virta, the company that caught Bhattacharyya's interest, is geared at helping people with type 2 diabetes get off their meds by coaching them to adopt lifestyle changes, including carb restriction. Its doctors have mixed feelings about body-hacking venture capitalists trying to get into nutritional ketosis, without supervision.

"If you only try it for a month, you aren't reaping the benefits," says Sarah Hallberg, Virta's medical director. "And if you're not feeling well, it's probably an indication that you're not doing it right." For Virta, she said, the nutritional regimen is only one part of an overall treatment plan.

Venrock partner Bryan Roberts gave nutritional ketosis a shot after investing in Virta. His rationale for trying it was to provide product development feedback, but he also lost ten pounds after enrolling in the program.

Likewise, Vishal Vasishth, a managing director at Obvious Ventures, took Virta up on its offer to try out the product, which includes health coaching and peer support. "I had a great experience," he said. "And I didn't feel like I was having to make any sacrifices."

Other investors became curious about the diet after meeting Virta Health's CEO Sami Inkinen.

Inkinen was previously a co-founder of online real-estate company Trulia. His journey into health care began when he learned he was at high risk of type 2 diabetes, despite being an endurance athlete.

"A powerful tool, but a lot of things can go wrong"

Inkinen, who once rowed from Monterey to Hawaii with his wife for a wedding anniversary, said he was able to get his blood sugar levels under control after working with scientific experts who had spent their careers researching the role of ketogenic diets in treating diabetes.

"In the past, I was eating a carb-rich diet and I can't tell you how many times I would literally fall asleep with my head on the keyboard at 3pm," he said.

He built up a team of scientists and physicians to build out an "online diabetes-reversal clinic," which later became Virta. The company launched with $37 million in funding, as well as promising results from a clinical trial run. A study found that after 10 weeks on the program, 56% of a group of 262 adults with the disease were able to lower their blood glucose to non-diabetic ranges.

Despite being a proponent of the approach, Inkinen wouldn't recommend it to everyone. "Outside of Virta's work, there's a lot of people biohacking themselves," he said. "It's a little scary to me because it's a powerful tool, but a lot of things can go wrong."

Some VCs who have tried the diet described a slew of positive effects, including weight loss and sustained energy throughout the day. Others said it caused headaches, at least in the initial weeks, and mood swings.

Another side-effect of ketogensis is bad breath, which often smells sickly sweet, although it's typically temporary. Only one investor reported needing to inform a partner at his firm about his unpleasant odor.

Dan Scholnick, an investor with Trinity Ventures, became aware of ketosis through his investment in Bulletproof Coffee. Both times he tried it, his breakfast included Bulletproof's coffee, butter, and "Brain Octane Oil" concoction. Scholnick said it would sustain him until lunch.

For Scholnick, ketosis is a more extreme version of a broader trend, in which those in his network are waking up to the dangers of sugar consumption. "Almost every investor I know in Silicon Valley is on some form of low-carb diet," he said.

Correction: Sami Inkinen is the founder of real estate company Trulia.