A woman became obese after a fecal transplant -- hinting at the complexity of how obesity works in the body, experts say.
The unnamed woman weighed 136 pounds -- but gained 34 pounds over the next 16 months -- going from a healthy body mass index to an obese one, according to a case study published in an Oxford Journal called Open Forum for Infectious Diseases.
"The patient actually said this: 'From the moment I had the fecal transplant, I felt like a switch flipped in my body,'" said. Dr. Colleen Kelly, a gastroenterology at the Warren Alpert School of Brown University. "She felt like prior to the fecal transplant, she had never had to worry about weight."
How you recognize what "enough," "too little," and "too much" are are based on a complicated set of hormonal and nervous system cues. When that system tips too far one way or another you're inevitably going to start gaining weight or have trouble building muscle.