So, I’ve been researching for an apocalyptic book, and I was wondering about the effects of prolonged, minimal food on an 18-year old male. He scrounges enough food to survive and be reasonably active, but I’m wondering what that would look like/what effects it would have. Thanks!
I read a book on a guy that spent 120 days in a life raft in the ocean, and he did not fair well. One thing that he noted was, upon starving for that long, when you eat real food again, you get sick because your stomach cannot handle it. Peanut Butter was originally intended as a medicine of sorts for this condition for starving children in the depression era. Another thing to consider is the need for Vitamin C. Only humans and hamsters need vitamin C, but it stops Scurvy. It is a horrific disease that you could include, or eat purposefully for, so the character does not get affected by it. In an apocalyptical situation, if the sun is obscured, Vitamin D might be an issue too. That affects sleep and mood.
If he gets a bare minimum of calories to at least maintain his mass and bodily processes functioning, would be on the scrawny side, but still able to be active.
It might be important to note that the stomach can swell up when you are malnourished, making it look like you've had your fill. Here are some links: https://en.wikipedia.org/wiki/Kwashiorkor https://www.livestrong.com/article/505253-swollen-stomachs-in-malnutrition/
Somewhat ironically hoarding food (instead of actually eating it) can be an effect of starvation. On season 3 of Alone one of the contestants had preserved 33 fillets of fish, but he starved and had to be evacuated medically because he was hoarding instead of eating it. Starvation can do weird things to the mind.
The brain needs a constant supply of glucose to function correctly as it cannot store it like muscles can. The brain is also around 60% fatty tissue so prolonged malnutrition/starvation can lead to brain atrophy and psychological ill health and strange behaviours. This is partly why anorexic patients can appear so illogical and fearful of food. Malnutrition can also lead to significant physical symptoms related to a lack vitamins and minerals - heart palpitations and arrhythmias, digestive issues, neurological issues, muscle wastage, weakness, poor healing etc etc. Also, an 18 year old male may still be experiencing final stages of puberty, which consumes a huge amount of calories, so hormone levels and bone density might be affected by malnutrition.
I thought of Auschwitz and the starvation diets during WWII. Here's a description of food intake and resulting affects on the body. This might lead to more details. http://auschwitz.org/en/history/life-in-the-camp/nutrition
