Well, not too many longer-term lockdown calorie restriction trials have been done since WWII, certainly none with anything like the enormous documentation done by Ancel Keys. However, back in 1991-1993, eight humans were more or less hermetically sealed into a 200 million dollar greenhouse in Arizona called the Biosphere 2. A lot of things went wrong there, including growing insufficient food to supply the crew. Not only do we have research papers written about the experience, but also books and press articles describing in more detail what happened.

My information for this post comes from a research article by Dr. Roy Walford, and one of the biospherian's books, The Human Experiment: Two Years and Twenty Minutes Inside Biosphere 2, by Jane Poynter. There are also a number of published scientific papers available, some accessible from the Biosphere 2 website, and a decent wikipedia article. The eight crew members were of varying age, sex, and some were somewhat overweight at the start of the experiment, while others were lean.

First, a little background. Biosphere 2 was meant to be a study of a large (3.15 acre) sealed ecosystem, with desert, ocean, rainforest, agriculture etc. along with human habitat and support. In some respects it would offer the first experimental large-scale look at how ecosystems interact, insights into the carbon and nitrogen cycles, and also a possible first blueprint for recreating Earth (biosphere 1) for space colonization. The project was originally conceived and executed by a group of adventurers, artists, and philosophers known as the Synergists, who had the financial backing of Texas billionaire Ed Bass. The Synergists had a number of other enterprises, including an art gallery in London, a cattle ranch and pastoral restoration project in Australia, a ranch and retreat in New Mexico, and an oceanic research vessel called the Heraclitus. Biosphere 2 was a heroic effort, and beautifully constructed.

As a private venture, the designers and leaders had a lot of leeway as to how the whole experiment would be conducted, and what sort of people would be chosen as the 8 member crew to live in the sealed ecosystem for two years. Thus the crew had some scientific experience, and there was a doctor, but many were adventurers who had lived a Synergist life, sailing the world doing research and working in remote regions of the ocean and Australia. Since the two years would be isolating and require hard physical labor, ingenuity, and technical skills, these weren't the worst people to close up inside. But the human element remained problematic throughout the history of Biosphere 2.

The overall goal of the first Biosphere experiment was to keep it sealed, rather like a spacecraft far from home for the whole two years. Nothing other than thermodynamic energy (such as sunlight) and electronic communications would go in or out. Everything would be recycled. In case of medical emergency, an airlock was created so it would be possible for supplies and humans to go in and out without messing up all the measurements. But considering that for the first time, humans were creating a complex ecosystem and populating it with everything from scorpions to microbes to coral reefs to crops and pests, to have success or failure balance on the "closure" of the experiment for such a long time seems, well, an incredible undertaking doomed to fail. But that is how the media, the biospherians, and the leadership of the venture viewed it then. That goal led to some fairly... interesting decisions along the way, especially with respect to the health of the crew. But turns out we did get another semi-starvation experiment out of it!

Prior to closure, the biospherians were already working inside the Biosphere, growing crops, making sure everything worked, etc. Jane Poynter, the crew member responsible for Agriculture, had predicted that they would be able to grow 80% of the food they needed within the biosphere. This was actually quite an achievement as the farm was 1/2 acre or so, and had to be entirely organic and self-sufficient - so no chemical fertilizers, no pesticides (as any poisons they sprayed on the plants would be sealed up inside the Biosphere with them). According to Jane, however, this number was not acceptable to management, and that 80% was somehow turned into 100% by putting the crew on a "calorie restricted, low-fat, nutrient-dense diet." They did consume a bit of goat milk and meat and eggs about once a week, but otherwise, the diet was mostly vegan. To give you an idea, over the course of the first year, the diet was about 50% sweet potato, and 31% of the fat they consumed was from the bananas.

The doctor on the crew, Roy Walford, had spent much of his career researching low-calorie diets as they relate to longevity, so this was the perfect experiment for him. Unfortunately he would die of ALS (commonly known as Lou Gehrig's Disease) at the age of 71 in 2004. He did publish several papers on the biospherian diet, one of which we'll review now, optimistically titled: "The calorically restricted low-fat nutrient-dense diet in Biosphere 2 significantly lowers blood glucose, total leukocyte count, cholesterol, and blood pressure in humans." Free full text, so go take a look. Actually, go ahead if you haven't already and look at my first Dieting Can Make You Lose Your Mind post and then go take a look.

It is perhaps predictable that Biosphere 2 had some crop problems, and the crew in the first six months was restricted to an average of 1780 calories daily. Now that's more, actually, than I would be allowed on any number of popular commercial dieting plans, but the biopsherians were engaged in hard physical labor much of the day. The carbon dioxide levels were rising, so they continuously had to harvest and sequester biomass all over the facility, and shovel and scrape carbonate off their home-made natural CO2 scrubber. Not to mention the farming itself, harvesting rice paddies, threshing wheat, milking goats - it was constant hard work.

Some of the glass panels admitted UV light to help the reptiles survive, but the humans were allowed supplementation with 400 IU vitamin D, vitamin B12, folic acid, 400 IU vitamin E, 500 mg of vitamin C, and calcium. They ate three meals a day, equal portions between men and women.

Not surprisingly, the Biospherians lost weight. Lots of weight. Men lost 16% of their BMI in 6 months, women 11%. Average systolic blood pressure decreased from 109 to 89, and diastolic BP decreased from 74 to 58. Mean total cholesterol decreased from 191 to 123. HDL fell from 62 to a dismal 38. The "risk ratio" of total cholesterol to HDL remained about the same. Triglycerides decreased in men (from 139 to 96) and increased in women (from 78 to 114). Fasting glucose fell from 92 to 74.