Nine volunteers, aged 36 to 49, took on the 12-day Evo Diet, consuming up to five kilos of raw fruit and veg a day food closer to what our ape-like ancestors once ate.
No more processed foods and saturated fats. Goodbye to great taste and hello bland health.
Locked up in a tented enclosure at Paignton Zoo, Devon, next to the ape house, in an experiment filmed for TV.
The idea, says Jill Fullerton-Smith, who helped organise the trial, was that modern diets, often dominated by processed foods and saturated fats, cause costly health problems.
Nearly half Britain's 117,000 annual deaths from coronary heart disease are linked to high cholesterol, according to the British Heart Foundation. And while the government urges everyone to eat five portions of fruit and veg a day, obesity is still rising because the fruit and veg is served with a plate of chips and a fried egg on top.
So could an experiment on ordinary people's lives deliver the healthy eating message? Only if the price of healthy food is lowered and they make it taste nice and less work and time to prepare.
The regime was devised by nutritionist and registered dietician Lynne Garton and King's College Hospital.
It was based on research showing such a diet could have health benefits for cholesterol levels and blood pressure, because it is made up of the types of foods our bodies evolved to eat over thousands of years.
Ms Garton looked for inspiration to the plant-based diet of our closest relatives, the apes, and devised a three-day rotating menu of fruit, vegetables, nuts and honey. The prescribed menu was:
safe to eat raw;
met adult human daily nutritional requirements; and provided 2,300 calories - between the 2,000 recommended for women and 2,500 for men.
Volunteers could also drink water. In the second week, standard portions of cooked oily fish were introduced a nod to a more hunter gatherer lifestyle though no yummy wild boar was served.
Among the volunteers was Jon Thornton, 36, a driving instructor from Sheffield, who had never eaten vegetables, from childhood upwards.
Weighing in at almost 19-stone, his typical diet was breakfast was four slices of toast; at 10am a bacon sausage and egg sarnie followed; fish and chips for tea and a Chinese take-away before bed. Sounds great to this reporter.
That was before his fat domineering wife signed up Mr Thornton for the experiment. Over 12 days he lost 5.7kg (12.5lbs), and reduced his cholesterol by 20%. His blood pressure also fell.
Despite nearly backing out at the start the first day's food arrived in a cool-box, was raw and he was distinctly uncomfortable with the idea of tasty broccoli (as found in the jungle) he was converted to eating vast portions of fresh fruit and veg as if he had a choice.
If our Ape ancestors could order a Chinese take away I think they would instead of eating raw broccoli, and they say water boarding is torture.
"I didn't feel any loss of energy, I didn't feel ill at all," he says. "It's not a diet you'd recommend as a diet itself, but it worked to bring my cholesterol and blood pressure down."
Nothing to do with 12 days off work away from inexperienced drivers.
With so much food bulk and plenty of calories the subjects did not go hungry indeed most failed to finish their daily ration, I bet it was the broccoli left over.
And once they were over the withdrawal from caffeinated drinks and some foods, says Ms Garton, they enjoyed good energy levels and mood.
The only draw back was the extreme farting, how can you smell rotten eggs without consuming eggs? Overall, the cholesterol levels dropped 23%, an amount usually achieved only through anti-cholesterol drugs.
The group's average blood pressure fell and they lost weight not the aim of the experiment.
To produce an environment closer to that of our closest cousins the Chimpanzees the group were encouraged to kill and eat on of their own with extreme violence.
For Jon, life has changed since he was "released" from the zoo. He has gained a little weight but now says he only eats when hungry and knows good food can help health and longevity, he is now wise beyond his years .
He can play football because his knees no longer hurt under the extra weight and he goes cycling.
If he only lost 12 lbs and has since put some back on I suspect it is all in his head.
He even managed to hold out at the most tempting time of year. "For the first time in 36 years this year I had vegetables with my Christmas dinner," he says. "Usually, I say no to them and have a few extra roast potatoes instead."
However his IQ has dropped by 30 points which he could not afford to loose, his penis has shrunk to the average size of that of a male gorilla which is 3 inches long and about as thick as a pencil and he has had an increase in body hair.