Daniel Lubetzky, a 'Shark Tank' star, admits to being addicted to checking his work email late at night: "I was trapped in email servitude."

Daniel Lubetzky states that he no longer prioritizes work over sleep, and as a result, he is now more productive.

Lubetzky, the billionaire Kind Snacks founder and newest permanent investor judge on ABC's "Shark Tank," was once a major night owl. He couldn't relax without clearing his inbox, leading to countless all-nighters.

"Lubetzky, 56, admits to having an obsessive personality when it comes to emails. He couldn't take it if there were any waiting to be read, and he would become enslaved by his inbox. After his kids and wife went to bed at 10 or 11 at night, Lubetzky would start checking all his emails. Sometimes, he would finish as late as 2, 3, or 4 a.m."

In 2018, Inc. reported that his work ethic helped Kind double its annual sales for more than 10 years in a row. However, he now admits that his love for being busy caused him to neglect his own health, resulting in "severe, chronic sleep deprivation" due to only getting four hours of rest every day for many years.

Lubetzky has made an effort to live healthily since the start of the Covid-19 pandemic, he claims. He strives to go to bed at a reasonable time and maintain a consistent sleep schedule, even if there are still unread emails waiting.

"Lubetzky states that it has helped him get better quality sleep, allowing him to have more time for workouts and be more focused and clear-headed at work, resulting in increased productivity."

According to the Centers for Disease Control and Prevention, approximately one in three adults in the United States fails to obtain the recommended seven hours of sleep each night. The National Institutes of Health warns that chronic sleep deprivation can increase the risk of developing heart disease, kidney disease, high blood pressure, diabetes, stroke, obesity, and depression.

Lubetzky follows in the footsteps of billionaires such as Elon Musk and Bill Gates, who have given up sleep to accomplish their goals. Musk stated in an interview with CNBC last year, "I've tried to sleep less, but even though I'm awake more hours, I get less done. And the brain pain level is bad if I get less than six hours of sleep per night."

In a 2019 blog post, Gates admitted that his all-nighters had a "big toll" on him. Now, he strives to get at least seven hours of sleep each night.

Lubetzky can determine his health changes by comparing old and new photos of himself, he claims.

"Lubetzky states that looking at pictures of him from 10 to 15 years ago, he appears 10 to 20 years older due to his pudgy and pale appearance. However, he acknowledges that he is now developing better habits to take care of himself."

CNBC has the exclusive rights to air "Shark Tank" off-network.

To become a successful and confident communicator, enroll in CNBC's online course, "Become an Effective Communicator: Master Public Speaking." Our program will teach you how to speak clearly and confidently, manage your nerves, choose the right words, and use effective body language to make a great first impression. Sign up now.