Ketogenic dieting has become a favorite pastime of Silicon Valley techies who want to hack their bodies to improve energy levels and performance. The regimen involves eating foods that are high in fat and some protein, while keeping carbohydrates to a minimum.

The goal of ketogenic diets is to get body to a state calld "ketosis," which requires keeping carbohydrates to less than five percent of daily caloric intake. Once that happens, the body burns stored fats instead of recently eaten carbs, resulting in a buildup of acids called ketones within the body.

Some critics say "keto" is just another fad diet, like Atkins or Whole30, but others rave about the benefits of being in ketosis, ranging from weight loss to increased energy.

Ketones can actually be measured in the blood, the urine and the breath, which is how many people on the diet figure out if their carb restriction is having an impact. But measuring it through the blood or urine is a bit much for some.

So Keyto, a new start-up in the space, aims to make it easier for people on ketogenic diets to track their body's transition into ketosis by simply blowing into a device. It was founded by Ethan Weiss, a cardiologist at UC San Francisco, and former Weight Watchers vice president Ray Wu.

Weiss offered me the opportunity to join the beta program and get early access to the device, as I've long been curious about the keto diet. I'd heard from advocates of the diet, including Weiss, that it can help with afternoon energy slumps, which sounded appealing. I often feel tired in the middle of the day, and rely on caffeine or a sugary snack to keep going.

Weiss provided me with a device that resembles bright orange breathalyzer to assess if I'm in ketosis. I also downloaded the Keyto app, which I used to search for foods to find out if they're keto-friendly or not.