The Unofficial Hunger Games Companion by Lois H. Gresh

aside for the moment the idea that people often eat too much, let’s return to the unpleasant topic of starvation. As the body grows increasingly hungry and without food, the brain ceases to register the hunger as acutely as it recognizes it in the first stages of starvation. The person feels less hungry and is satisfied by increasingly smaller amounts of food.
    Eventually, hunger leads to death as the body literally eats itself. It may be hideous to consider that your body may one day cannibalize you, but alas, it is true: If you starve long enough, you will be your own cannibal.
    As the brain runs out of sources of glycogen, it cannibalizes the body’s protein to get it. The muscles are used, and finally, the heart.
    Think about newborn babies, who awaken every few hours at night because they’re hungry. They’re too young to produce sufficient glycogen, which is the way our bodies store sugar, and they need glycogen to think, to move their muscles, to keep their cells functioning. The calories we ingest eventually turn into glycogen in our bodies.
    When the body is hungry, it uses stored calories as fuel, with approximately 85 percent of the calories coming from fat, 14 percent from protein, and the remaining 1 percent from carbohydrates that come from blood glucose or liver and muscular glycogen. If your body has 100,000 calories stored in fat, 18,000 in muscles, and 300 in glycogen, you won’t last too long.
    Minimally, you need glucose for your brain. But when you fast, at first the glucose level drops in your blood, which in turn, drops the insulin level circulating in your blood. As the insulin drops, your body tissues release fatty acids that travel through your blood to the liver. A hormone is released that raises your blood sugar level. Your liver converts and depletes its glycogen—still within the first day of fasting. In addition, your liver converts the glycerol that, along with fatty acids, make up the triglycerides in your body, and the lactic acid in your muscles also starts converting back into glucose.
    All of the above happens within twenty-four hours of fasting. After thirty-six hours, your body relies on the use of protein to produce necessary glucose. Your muscles send amino acids to your liver and kidneys for glucose production, and your body adapts and uses less glucose, pushing the glucose produced by your muscles to your brain, where it’s most needed. Your body is now eating your muscles.
    At this point, your body revolts against its own cannibalization! You might have a headache and stabs of pain behind your eyes. If you continue to fast, then by the third day, most of your body’s energy is now coming from converting your muscles into glucose. In addition, your liver kicks into action and turns fatty acids in your body into ketone bodies, which cells can use instead of glucose. As your body desperately tries to save its remaining protein, that is, your muscle tissues, it sends ketone bodies into your brain; and by day four, ketone bodies are supplying much of the fuel for your struggling brain.
    After a week or so, you contract ketoacidosis , which typically is seen in people who suffer from diabetes. Too many fatty acids are in your bloodstream due to a lack of insulin. Ketone bodies are now supplying the vast majority of your brain’s fuel. Your intestinal walls shrink. Your glucose level is too high, dehydrating your body, and typically by week two or three, you slip into a coma or die.
    Typical Starvation Timeline:
How Your Body Eats Itself

24 hours
Insulin level drops.
    Blood sugar rises.
    Liver depletes its glycogen.
    Muscles start converting into glucose.

36 hours
Muscles provide protein for glucose.

3 days
Most of your body’s energy now coming from converting your muscles.
    Liver turns fatty acids into ketone bodies to take the place of glucose.

4 days
Ketone bodies supply much of your brain’s energy.

7 days
Your body is hit by ketoacidosis .
    Glucose level dangerously