Tree bark as food

Question

I saw a youtube video where this guy skinned a spruce tree stick and ate the bark while claiming it is nutritious. That got me curious since trees are everywhere and this could be a great tip so I tried searching for what kind of nutritional value it would have exactly. All i found was this page which says that the bark is "relatively nutritious" and packs around 500-600 calories per pound.

I'm not sure they realize that a grown human being on average needs 2000 calories a day to survive for longer periods of time so you'd have to eat around a metric ton of the stuff per day. Maybe it was a typo and they meant kilocalories but that would mean the bark has to be mostly fat and all the sources I've seen say its mostly carbs.

Does anybody have solid information on what kind of nutrition tree bark has?

Answer 1

According to this entry in the Swedish wiki, flour made out of pine bark contains about 82kcal/100g, or 400 kcal/pound (thanks to a comment).

This flour is not made of the bark itself, but the thin layer between the bark and the wood. It is harvested in the spring when rising sap makes it come of rather easily. To make it into flour you have to dry it, roast it and then you sift it and presto. You have your flour.

Answer 2

Most probably the numbers were typo. There are numerous websites on pine tree bark eating. So far the best I found is this one from Survival Topics. I agree with the statement, this option should be an emergency option. The 2500 kcal requirement is more than the actual minimal need of energy per day. More like 1700-1800 given by the numbers of FAO research. So if we ask for survival, those few pounds of bark could save your life in emergency and give enough energy to hunt, find more suitable food for yourself, with @MarcusWigert's answer the nutrition fact would end up with 400 kcal/pound.

Answer 3

This doesn't really answer the question of how many calories per pound, but why eat the bark when the pine has so many good edible parts: Pining for You (Eat The Weeds).

Answer 4

I'm a biochemist, and if there's 82 kilo calories (or "calories" as used by nutrition science and how I will use the unit term from now on - because in standard conversation no one uses kcals), per 100g of pine flour then there's slightly less (12%) than 82 calories per 100 g of pine bark. There's 12% moisture in pine bark solids to evaporate when drying to obtain the flour. So, simply add 12% back to the weight of the sample and you have 82 calories per 112g of solid pine bark which translates to 82÷112×454=332.39 calories per pound.