As many people around the world did earlier this week, I became attached to the television watching the 33 Chilean miners being rescued from the mine they were trapped in for 69 days. The rescue team had numerous concerns about the rescue process, including whether each miner would be able to fit inside the Fenix rescue capsule – the capsule has a 28-inch diameter enclosure and was designed to fit one body.

Nutrition was a major concern while the miners were trapped. The miners looked great when they emerged, thanks in part to a strict diet and exercise program they followed while underground.

After the collapse but before they were located, each miner survived on two mouthfuls of tuna, a sip of milk, and a few bites of crackers every other day. This resulted in an average weight loss of 17-22 lbs. for each miner.

After they were found (17 days later), their first food from the outside was a 7 oz. serving of Supportan, a medical, milk-based nutritional supplement, which was sent in packets. Urine tests showed that about half of the miners were dehydrated, and their muscles were breaking down, as a result of starvation and, possibly, from sleeping on hot rocks.

The miners were told to nearly double the amount of water they were drinking. Liquid gels with protein and vitamins were also sent down. Over time, the miners were able to increase their consumption of Supportan, and start consuming real food. They were slowly brought back to a full menu, in order to avoid refeeding syndrome (a potentially fatal complication of starvation). Eventually, the miners were kept on a diet of approximately 2,300 calories a day and told to exercise for up to an hour a day or more, depending on their fitness level.

Some of the miners complained that they were hungry and jokingly requested beer and wine. On Sept. 18, Chile’s national holiday, each man got an empanada (the meals were packed individually with each miner’s name to avoid conflict over portions).

NASA consulted with Chilean officials regarding the miners diet and for their safe ascent back to ground level, in order to avoid motion sickness, a sudden drop in blood pressure, and locking knees (which impedes proper blood circulation to the brain and heart). In preparation for the ascent, the miners drank up to 42 ounces of an electrolyte solution and took salt tablets in the 12 hours prior to the evacuation. They also wore girdles to prevent blood from pooling in their legs and feet.

Amelia Pons is chief coordinator of nutrition at the Copiapo Regional Hospital, where the meals for the miners were prepared.