Wow, this surprised me. This is the sort of thing that I would write off as nonsense on first glance if it weren’t from Robert Freitas, who is legendary for the rigor of his calculations. Here’s the bit, from a World Future Society update:

The Issue: Hunger

The number of people on the brink of starvation will likely reach 1.02 billion — or one-sixth of the global population — in 2009, according to the United Nations Food and Agriculture Organization (FAO). In the United States, 36.2 million adults and children struggled with hunger at some point during 2007.

The Future: The earth’s population is projected to increase by 2.5 billion people in the next four decades, most of these people will be born in the countries that are least able to grow food. Research indicates that these trends could be offset by improved global education among the world’s developing populations. Population declines sharply in countries where almost all women can read and where GDP is high. As many as 2/3 of the earth’s inhabitants will live in water-stressed area by 2030 and decreasing water supplies will have a direct effect on hunger. Nearly 200 million Africans are facing serious water shortages. That number will climb to 230 million by 2025, according to the United Nations Environment Program. Finding fresh water in Africa is often a huge task, requiring people (mostly women and children) to trek miles to public wells. While the average human requires only about 4 liters of drinking water a day, as much as 5,000 liters of water is needed to produce a person’s daily food requirements.

Futurist Fixes

1. The Food Pill. In the future, we may see a type of pill for replacing food, but experts say it likely would not be a simple compound of chemicals. A pill-sized food replacement system would have to be extremely complex because of the sheer difficulty of the task it was being asked to perform, more complex than any simple chemical reaction could be. The most viable solution, according to many futurists, would be a nanorobot food replacement system.

Dr. Robert Freitas, author of the Nanomedicine series and senior research fellow at the Institute for Molecular Manufacturing spoke with FUTURIST magazine senior editor Patrick Tucker about it.

In his books and various writings, Freitas has described several potential food replacement technologies that are somewhat pill-like. The key difference, however, is that instead of containing drug compounds, the capsules would contain thousands of microscopic robots called nanorobots. These would be in the range of a billionth of a meter in size so they could easily fit into a large capsule, though a capsule would not necessarily be the best way to administer them to the body. Also, while these microscopic entities would be called “robots,” they would not necessarily be composed of metal or possess circuitry. They would be robotic in that they would be programmed to carry out complex and specific functions in three-dimensional space.

One food replacement Dr. Freitas has described is nuclear powered nanorobots. Here’s how these would work: the only reason people eat is to replace the energy they expend walking around, breathing, living life, etc. Like all creatures, we take energy stored in plant or animal matter. Freitas points out that the isotope gadolinium-148 could provide much of the fuel the body needs. But a person can’t just eat a radioactive chemical and hope to be healthy, instead he or she would ingest the gadolinium in the form of nanorobots. The gadolinium-powered robots would make sure that the person’s body was absorbing the energy safely and consistently. Freitas says the person might still have to take some vitamin or protein supplements but because gadolinium has a half life of 75 years, the person might be able to go for a century or longer without a square meal.

For people who really like eating but don’t like what a food-indulgent lifestyle does to their body, Freitas has two other nanobot solutions.

“Nutribots” floating through the bloodstream would allow people to eat virtually anything, a big fatty steak for instance, and experience very limited weight or cholesterol gain. The nutribots would take the fat, excess iron, and anything else that the eater in question did not want absorbed into his or her body and hold onto it. The body would pass the nurtibots, and the excess fat, normally out of the body in the restroom.

A nanobot Dr. Freitas calls a “lipovore” would act like a microscopic cosmetic surgeon, sucking fat cells out of your body and giving off heat, which the body could convert to energy to eat a bit less.

Where can you read more about Robert Freitas’s ideas? In the January-February 2010 issue of THE FUTURIST magazine, Freitas lays out his ideas for improving human health through nanotechnology.

Yes, there are many other technologies that could help out better with hunger right now. The most important are the three initiatives singled out by Giving What We Can as being high-leverage intervention points: schistosomiasis control, stopping tuberculosis, and the regular delivery of micronutrient packages. Another is the iodization of salt. How can these stop hunger? Well, the diseases and ill health caused by the absence of these measures is so great that alleviating them will increase the total amount of time that people have available to engage in farming, which in the short term will alleviate hunger more effectively than any direct measure. Delivering food in the form of aid fosters dependence.

Anyway, the summary of Freitas’ food bot ideas above seems very limited. I’m sure that Freitas has worked out the design in greater detail. For instance, are the nanobots he is talking about is powered through a radioisotope rather than a nuclear fission plant, and the text doesn’t make that clear enough, in my opinion. I wonder — how is it that gadolinium can be broken down into all the nutrients the body needs? Wouldn’t a large amount be required, because fueling the chemical reactions of the body requires bulk and mass no matter how you slice it? I am seeing a lot of technical questions and holes in the idea, as it is brusquely presented above. I will email Freitas and ask him to point us to the proper writings.