A 45-year-old tech tycoon who spends upwards of $2 million per year to bio-hack his body into aging backwards said he eats dinner at 11 a.m. to achieve an 18-year-old physique.

Bryan Johnson — who also has said he uses a machine to count his nighttime erections and has taken steps to make his rectum perform like a teenager’s — made his fortune in his 30s when he sold his payment processing company Braintree Payment Solutions to EBay for $800 million in cash.

In addition to swapping blood with his teenage son and taking more than 100 supplements a day, Johnson said his daily routine also includes consuming all of his food for the day before the clock strikes noon.

Johnson responded on Twitter to a commenter who quizzed him over his eating schedule.

“Is this a typo? Can you clarify?” tweeted Twitter user Martina Markota, who wondered whether the tech mogul actually ate his dinner before noon.

“My final meal of the day is at 11 am. I eat between ~6-11am,” Johnson tweeted.

Johnson is a practitioner of “time-restricted eating,” also referred to as “intermittent fasting,” which means cramming meals into a window so as to allow for longer periods of digestive rest.

The practice, which has been made popular in recent years by celebrities, has been touted for its purported health benefits, including increased energy, weight loss, and greater mental focus and cognition.

Johnson became a social media sensation earlier this year after a report detailing his extreme daily ritual which is aimed at getting all of his major organs — including his brain, liver, kidneys, teeth, skin, hair, penis and rectum functioning as they were in his late teens.

In May, it was learned that Johnson enlisted his 17-year-old son, Talmage, to be his personal “blood boy” by providing transfusions in an hours-long process whereby plasma is fed directly into the dad’s veins.

Using plasma as an anti-aging technique caught the attention of wellness junkies when scientists literally stitched young and old mice together so they shared a circulatory system, Bloomberg reported.

The older rodents showed improvements in their cognitive function, metabolism and bone structure, while the younger subjects showed that frequent blood donation could have positive effects.

However, there is little human-based data, leaving many researchers to view plasma-swapping longevity techniques as inconclusive, according to Bloomberg.

Known as Project Blueprint, Johnson adheres to a strict vegan diet totaling 1,977 calories per day, a one-hour-long exercise regimen, high-intensity exercises three times a week, and going to bed at the same time each night.

What I do may sound extreme, but Im trying to prove that self-harm and decay are not inevitable, Johnson told Bloomberg News.

Johnson wakes every morning at 5 am, takes two dozen supplements, works out for an hour, drinks green juice laced with creatine and collagen peptides, and brushes and flosses his teeth while rinsing with tea-tree oil and antioxidant gel.

Before bedtime, Johnson wears glasses that block blue light for two hours. He also constantly monitors his vital signs and undergoes monthly medical procedures to maintain his results, including ultrasounds, MRIs, colonoscopies and blood tests.

While sleeping, Johnson is hooked up to a machine that counts the number of nighttime erections. He also takes daily measurements of his weight, body mass index, body fat, blood glucose levels and heart-rate variations.

Johnson’s part of a trend that has become fashionable among Silicon Valley tech executives who have vowed to crack the code on aging and longevity.

Peter Thiel, the PayPal co-founder, has invested millions of dollars into a nonprofit that seeks to make “90 the new 50 by 2030.”