SAN FRANCISCO, Calif…July 29…Forget South Beach. If you really want to shed the pounds Alcatraz is the place for you.

“The Rock,” California’s newest spa,which opened last month in the abandoned penitentiary on Alcatraz Island, has become the number one diet destination for image conscious celebrities.

“Fat plus Fear equals Fitness ,” says spa founder Dr. Immer Kronkheit. “We eat, exercise and think like hardened criminals.”

A holistic nutritionist, Kaballah sex therapist and licensed cannabis dispenser in Southern California, Dr. Kronkheit was long puzzled by what he called “flab creep” among even his most dedicated patients.

“People could lose twelve to fourteen pounds in a few weeks on the crash part of the diet, but when they went on maintenance they would watch in a panic as the flab crept back.”

Kronkheit realized that only a major metabolic change would keep the pounds off permanently.

Inspiration came when he read a study in The Social Science Journal which advanced the astonishing hypothesis that criminals were the fittest members of the population.

The study examined 5000 inmates in the Arkansas prison system. Using body mass index, a measure of height and weight, to assess fitness it concluded that the healthy, athletic mesomorphic body type made up “an unusually large percentage of the population, from 62 to 73 per cent.”

“This was much larger than the proportion in the national population, which is consists mostly of endomorphs (fatties)n and ectomorphs (skinnies),” Kronkheit said.

Anecdotal observation showed that inmates exercised more frequently and strenuously than the average individual.

“Exertion in the form of competitive sports, in-cell activities and homicidal attacks on officers and other inmates took up more than forty per cent of the inmates’ waking hours,” Koronkheit says. “Follow up studies showed that those inmates who left prison alive and in one piece weighed less, did more push ups and ran faster than when they entered…And they were better dancers…”

Kronkheit put together a program that replicated the diet and daily routines of inmates in maximum security facilities. He rented Alcatraz, which has been closed since 1963 and within weeks had a six month waiting list.

“Our program is not for the faint of heart,” Kronkeheit warns. “Customers must pass a casual physical and extensive credit check before acceptance.”

What Kronkheit calls “the sentence” begins at dawn when the customers are herded onto a rusty ferry by overweight, abusive ex MP’s, formally stationed at Guantanamo. Once on the island they are made to strip in the chilly reception center where they are prodded by defrocked priests and palsied proctologists and ridiculed for their flab, their odd shapes and puny endowments. “We find that humiliation is a tremendous appetite suppressant,” says Kronkheit.

Their cells are leaky and rodent infested. Cellmates, their diametric opposites in race, politics and sexual preference, have been chosen from a pool of ex convict volunteers. “It’s inspiring to see how many ex cons want to share their lifestyle,” Kronkheit says.

The first few nights are spent in sleepless terror. “Fear is especially effective for reducing love handles,” Kronkheit says.

The menus are counter-intuitive, emphasizing fat, sugar, salt and chemicals. The standard prison breakfast is sodium-rich pancake mix, grits, swimming in margarine and fructose enriched canned pineapple juice. Prison toothpaste is the cheap variety imported from China and rich in industrial solvent diethyleneglycol.

“This causes instant purging sweats and high fevers, which quickly deplete body fat,” Kronkheit says.

As in prison meals are timed for maximum inefficiency.

“Lunch is served at 11:15 long before the prisoners have gotten over their mid-morning nausea,” he says. “Dinner comes at 4 p.m. so the staff can beat the rush hour traffic.”

The prison diet emphasizes cheapness and convenience.

“We like to serve food at least an hour it was prepared to diminish vitamin content, Kronkheit says.”We keep the cold drinks like milk out to get warm and the hot beverages like coffee out to cool off.

“Powdered eggs, canned soups and fruits, pre packaged burgers and frozen pizza are a staple,” Kronkheit says. “We find that junk food combined with stress and poor body image really takes off the pounds.”

Smoking, illicit drug use and bootleg alcohol are part of the prison culture so Kronkheit encourages their use.”

There is no need for formalized exercise program. “Prison rituals encourage fitness,” he says. “After every meal Customers have to run a gamut back to their cells. They do pushups to develop the strength and stamina necessary to fight off their cellmates.”

And the treatment works. Average weight loss after thirty days is forty-two pounds. “We’ve had people lose so much they had to be put on IV’s and taken off on stretchers.,” Kronkheit says.

Since leaving the program, a few of his dieters have been implicated in bank robberies and carjackings. Kronkheit says this is “an interesting statistical anomaly.”

He has asked the Social Science Journal to do a study on it.