The experiment, which was filmed for television, was intended to show what happens when people abandon a modern diet filled with processed foods, according to organizer Jill Fullerton-Smith.
The structure of the diet, dubbed the "Evo Diet," was the brainchild of Lynne Garton, a nutritionist and registered dietician at King's College Hospital in London. Garton devised the menu based on the diet of apes -- the animals biologically closest to humans -- inspired by research that showed their plant-based diet is one human bodies have evolved to process over the millennia and can have beneficial effects on cholesterol and blood pressure.
In the first week of the 12-day study, the nine volunteers sat down to a daily meal of water and about 11 pounds -- or about 2,300 calories -- of honey, hazelnuts and fresh fruits and vegetables like watercress, broccoli, carrots, cabbage, tomatoes, radishes, strawberries, melons, mangoes, apricots, bananas, plums, figs and Satsuma mandarins. The foods were chosen because they were safe to eat in raw form, they sufficiently fulfilled the daily nutritional requirements of a human body, and they provided a calorie count in between the daily recommended values for men and women; 2,500 and 2,000 respectively. During the second week, the diet was adapted to mimic that of hunger-gatherers with portions of cooked, oily fish.
"There is no question that if more humans followed the diets of plant-eating animals, we would wipe out the disease epidemics now sweeping the globe," said Mike Adams, a holistic nutritionist who eats a partial raw vegetarian diet, and who is the author of "The Seven Laws of Nutrition." "When people who have been consuming cooked, processed foods make the switch to raw, vegetarian or vegan lifestyles, they rapidly see remarkable improvements in health and even reversals of conditions like diabetes, heart disease and cancer."
One participant, 36-year-old Jon Thornton, began the study weighing in at nearly 265 pounds, but by the end of the experiment had lowered his blood pressure, dropped 12.5 pounds, and reduced his bad cholesterol by 20 percent. Thornton admitted that his diet prior to the trial was quite poor -- consisting of things like bacon, sausage and egg sandwiches and deep-fried fish and chips -- and nearly left the experiment when the fruit and vegetables first arrived, but he eventually decided to stick with it and reported no adverse effects from the change.
Since the experiment ended, Thornton reported that his knees do not hurt like they used to when he plays soccer, and he has taken up bicycling. Even at Christmas, he managed to remember the healthy habits he had learned.
"For the first time in 36 years this year I had vegetables with my Christmas dinner," he said. "Usually, I say no to them and have a few extra roast potatoes instead."
Despite not being the portions of processed fare the participants were used to, the Evo Diet still turned out to be plentiful. Most of the tent dwellers did not finish their entire daily food ration. The only failure in the experiment was the part where the TV cameras were set up to record the "moments of unhappiness and grumpiness" that were supposed to occur while the subjects overcame their addictions to processed foods. However, once withdrawal symptoms of certain foods and caffeinated beverages passed, the participants were generally happy and energetic. There was some discomfort in the tent, but it all came from the gassy side effects of such a fiber-rich diet.
The participants used to consume saturated fat from 13 percent of their calories on average, but the cholesterol-making fat only accounted for 5 percent of calories by the end. The overall cholesterol drop for the entire group was 23 percent, which is a number that scientists have only attained through use of statin drugs in the past. The average blood pressure level of the group bordered on hypertension at 140/83 at the beginning of the trial, but it had been reduced to 122/76 after the 12 days were up. The average salt intake was double the recommended 6 grams per day, but ended up at 1 gram when the trial had finished. The group lost an average total of 9.7 pounds, despite the fact that weight loss was not a goal for the experiment.
"The main lesson that they took away was to eat more fruit and veg," said Garton.