Above: This stingray weighed over 100 lbs with an estimated whole caloric value of 60,000 kcal.

For those interested in the fascinating anthropological aspects of Naked and Afraid, Nathan has analyzed his experience and developed an optimal foraging strategy based on the available resources. 

Stingray: 130 kcal/100 g (data from shark, no reliable source for stingrays. National Nutrient Database)

Armadillo: 159 kcal/100 g (could not find reliable source.

Note: The above caloric values are conservative, as the participants consumed fat-rich portions of both species (nervous tissue, eyes, organs and skin) that are typically discarded prior to the calculation of the above values. The participants also consumed small fish, frogs and snails that contributed significant amounts of protein but few calories (< 100 kcal/day), as well as fruits of black palm and marmalada (guava).

Palm Heart 115 kcal/100 g (National Nutrient Database)

Approximate weights of whole foods:

Black Palm Heart: 200 g X 40 = 8,000 g (estimate from memory)

Stingray: 3,200 g +1,800 g + 1,800 g + 900 g = 7,700 g (estimates based on Length/Weight Conversions for Marine Fishes of Texas using southern stingray and wingspans of 18, 15 and 12 inches)

Armadillo: 900 g (estimate from memory)

Calories Consumed:

Black Palm Hearts: 9,200 kcal

Stingrays: 10,010 kcal

Armadillo: 1,431 kcal

Total: 20,641 kcal

Per day: 983 kcal

Per person per day: 491 kcal

In order for 2 people to live on the island indefinitely and lose no weight, they would have to procure the following each day (based on a 2,000 kcal/day diet, as very little work in terms of calories is required to procure these particular hearts and animal foods):

Palm hearts: 8 - 9 per day

Stingrays: 1 per day (15 inch wingspan)

The island was estimated to have a population of black palms and stingrays sufficient for a 21 day stay, but no longer. In addition to the 4 stingrays that were taken, approximately 6 additional stingrays (including much larger ones) were observed prior to the participants developing the appropriate tools and methods for procuring them. Based on these findings, 2 hunter-gatherers specializing in palm and stingrays would need to move every two to three weeks to sustain their diet indefinitely.