My contemplation of the world situation led down the line of "suppose there's just no food at all. How long can I survive, and how do I recover when food becomes available again?" We know that people in harsh circumstances can survive for days, or weeks, without eating. It's not pleasant, but many survive. Maybe they're stranded by a car wreck, migrating across barren terrain, or drifting in a life-raft after a ship sank... it happens. They go hungry, then they're rescued.
So, what happens next? I'll just quote Wikipedia:
Refeeding syndrome is a metabolic disturbance that occurs as a result of reinstitution of nutrition in people and animals who are starved, severely malnourished, or metabolically stressed because of severe illness. When too much food or liquid nutrition supplement is eaten during the initial four to seven days following a malnutrition event, the production of glycogen, fat and protein in cells may cause low serum (blood) concentrations of potassium, magnesium and phosphate. Cardiac, pulmonary and neurological symptoms can be signs of refeeding syndrome. The low serum minerals, if severe enough, can be fatal.
And, what to do about it? Wikipedia, again:
..., if phosphate drops to below 0.65 mmol/L (2.0 mg/dL) from a previously normal level within three days of starting enteral or parenteral nutrition, caloric intake should be reduced to 480 kcals per day for at least two days while electrolytes are replaced. Daily doses of thiamine, vitamin B complex (strong) and a multivitamin and mineral preparation are strongly recommended. Blood biochemistry should be monitored regularly until it is stable. Although clinical trials are lacking in patients other than those admitted to intensive care, it is commonly recommended that energy intake should remain lower than that normally required for the first 3–5 days of treatment of refeeding syndrome for all patients.
Now, I doubt that we're likely to have the ability to monitor blood biochemistry in a difficult situation. For now, I think it's sufficient to put a note in my emergency medical reference (along with the recipe for oral rehydration solution): "Just because you have it, don't eat it all! Resume eating gradually. 480 kcal per day is about 1/4 lb (140 g) of carbohydrates and protein (and less of fat). Have dry electrolytes and vitamins in reserve."
Tue, 04/19/2022 - 21:18
try wilderness rescue books or sites
Yep, we cant measure those things outside of a hospital. So there must be some kind of rule of thumb. But, yes, one of my offspring who does search and rescue mentioned this to me, that she cant give someone who hasnt had food for a long time food. It I remember, which is about even odds, I will ask her more. Basically, yes, you would have to go slow on food reintroduction if you cant get them to a hospital. And we do need to prepare for what to do without being able to get to a hospital and measure blood levels so it is good to bring up
Teresa from Hershey
Wed, 04/20/2022 - 15:08
Sounds like soup and broth to the rescue.
That sounds like -- if you don't know anything else -- clear soups and broths.
Some veg, bits of meat, bits of potato or noodle in the broth and plenty of liquid.
Then, after a few days, adding more solids (and more calories).
Wed, 04/20/2022 - 19:00
Yes, Reintroduction Slowly
The references I've read about this are from refugees in the 40 Years War era (1600s IIRC) where people who went without food for long periods, then got access to food, would overeat and have medical difficulties or death. The same can happen I believe if you have to go without water.
Thu, 04/21/2022 - 11:23
A related question: little food vs no food
A related question I have wondered about follows. As a thought experiment, say a person has at hand sufficient food to provide 500 kcal/day for 6 months and anticipates no resupply for that length of time. What is the optimal consumption pattern for the best physiological outcome? One might imagine 500 kcal/day each day, two real meals twice a week and fasting in between, or any of an infinite range of other options. Premodern societies may have understood the best strategy but I haven't a clue. While curious, I have never tried to research the question.
Sat, 05/07/2022 - 19:13
You'd also have to think about how to manage what energy (from food) you take in. I imagine cutting back on physical exertion as much as possible. In cold weather, burrow under a heap of insulation and let "the furnace" ease off on keeping you warm. I've heard a little bit about cold climate residents going into a sort of hibernation when there are no more farm chores to be done for the season. Cutting, splitting, and burning wood through the winter might be sub-optimal, if the calories saved by heating the house are more than spent by bringing in the fuel.