By Chris Adams

Deep inside a hospital in Phoenix, a federal research unit is measuring precisely what goes in Americans’ mouths and how their bodies then burn and process it.

The effort is overseen by Dr. Jonathan Krakoff, chief of the Obesity and Diabetes Clinical research section of the National Institute of Diabetes and Digestive and Kidney Diseases, part of the National Institutes of Health.

And when it comes to counting inputs and outputs, this team gets down to the granular level.

Krakoff, whose research has identified “spendthrift” and “thrifty” body types that can help predict a person’s susceptibility to weight gain and loss, led National Press Foundation fellows through his clinical research unit and the tools it uses to measure energy intake and expenditure:

  • A metabolic kitchen that prepares precisely measured foods that are given to participants in clinical research studies;
  • Automated vending machines that give participants choices on what to eat but requires a passcode so researchers know when and how much a participant has eaten;
  • A “whole room indirect calorimeter,” which is a sealed room with circulating air that a participant stays in for 24 hours so researchers can carefully measure energy expenditure based on air samples;
  • A process to collect, freeze-dry and burn participants’ daily intake and bodily waste, allowing an exact measurement of how many calories are ingested and have left the body.