Of all of Dr. Nowzaradan's difficult patients, Steven Assanti may be the most challenging. The 800-lb man proved he could lose weight in order to get gastric bypass surgery on TLC's "My 600-lb Life." But then, for some reason, he sabotaged his weight loss.

What's the problem? The 33-year-old can't (or won't) break one simple bad habit. And lifestyle choice is driving his obesity in a big way.

Steven Assanti slave to addiction

The Rhode Island man (who goes by "FatBoyGetDown" on social media) is crippled by obesity and a prisoner of his own bed. But his jailors aren't his 600 extra pounds as much as his addictions (and they are legion).

Assanti is at the mercy of a vicious Vicodin habit. Drug addiction plus being enabled by his father has turned Steven into a spoiled brat.

His younger brother Justin Assanti (who weighs nearly 600 pounds himself), says Steven victimizes everyone including hospital staff on "My 600-lb Life." His tyrannical temper got him booted out of several bariatric surgery programs. But Steven is also a victim of himself.

Steven Assanti can't kick control habit

Like many bossy, controlling people, the obese celebrity of Youtube is out of control. He's ruthlessly demanding and exploitative but expects others to bend rules for him. Is Steven just a manipulative jerk or is there more to it?

The "My 600-lb Life" patient is bedridden, so there's nothing he can do if people won't obey.

Clearly the reality television star has learned how to bully but as obnoxious as he his, Steven seems frightened by his own power. Is he crying out for someone to say no? Well, TLC's Dr. Now was willing to be that person.

For want of pizza Steven Assanti's weight loss was lost

Along with prescription pain relievers, the reality TV star is addicted to food.

Pizza is his kryptonite. When things go wrong, he makes his father order pizza. When things go well, Assanti demands it.

After being kicked out of the bariatric surgery program for ordering pizza, guess what Steven wanted? It may sound funny and pretty childish.

Mama June of "Honey Boo Boo" was addicted to Little Debbie cakes!

But this addiction is no joke. Junk food is poison to a morbidly obese person. However the good news is that for all his dangerous behavior, Assanti has proved he can lose weight.

Will chutzpah or pizza triumph? Watch "My 600-lb Life" to find out.