After nine months of participating in the lifestyle intervention, insulin sensitivity improved in 71 percent of the men and 58 percent of the women. Individuals with improved insulin sensitivity lost significant amounts of visceral fat (a mean reduction of 19 percent for women and 20 percent for men) and liver fat (a mean reduction of 35 percent for women and 44 percent for men) while reducing 3 to 5 percent of body weight.

"The participants who improved their health status as a result of diet and exercise started out with lower baseline levels of abdominal and liver fat," Machann said. "In our study, these two factors predetermined whether or not a lifestyle intervention would be successful for a particular individual."

Individuals who did not improve insulin sensitivity as a result of lifestyle changes lost much smaller amounts of visceral fat (a mean reduction of 4 percent for women and 6 percent for men). The men also lost less liver fat (a mean of 15 percent), and women gained a mean of 22 percent in liver fat.

"Our results demonstrate that with MRI and MR spectroscopy, we can determine who will benefit from dietary changes and exercise and who will need other interventions," Machann said.

Source: Radiological Society of North America