BABY, BABY, WHERE DID OUR LUNCH GO?

Your last meal didn’t wind up just in your gut. After a meal, your body begins
to apportion the calories to nutrient-hungry organs, growing muscles, and,
yes, your belly. Michael Jenson, M.D., a professor of medicine in the division
of endocrinology, diabetes, and metabolism at the Mayo Clinic, calculated this
breakdown of how your body processes food.
10 percent to the kidneys. Kidneys work to make sure the blood is balanced
with the right amounts of water and nutrients.
5–10 percent to the heart. The heart gets most of its energy from fat, which
provides more long-term energy for the hardworking heart than glucose can.
23 percent to the liver, pancreas, spleen, and adrenal glands. After the
liver pulls out nutrients, it stores excess calories as glycogen.
25 percent to muscles. Muscles require a constant source of energy just to
maintain their mass, so the more muscle you have, the more calories you
burn.
10 percent to the brain. Glucose is brain fuel. It can’t be stored long term,
which is why people often feel faint if they skip a meal.
10 percent to thermogenesis. The simple act of breaking down the food you
just ate takes up one-tenth of your calories.
2–3 percent to fat cells. Your fat cells grow and eventually divide as more
and more calories are deposited.
10 percent to no one knows where. Your body’s a big place, and some calories
go unaccounted for.
the standard army fitness test of situps, pushups, and a
2-mile run, researchers tracked their lower-body injuries (such
as lower-back pain and Achilles tendonitis) during a year of field
training. The 29 men who cranked out the most situps (73 in