Obesity was not always synonymous with a poor diet and excess. A new study in the United States shows, toddlers who have links (relations) are bad with their mothers tend to be obese when growing up.

These findings involving nearly 1,000 children. A quarter of them have a poor relationship with their mother. In this group, the risk increases when children become obese at the age of 15 years. In contrast, only 13 percent of children who have good relationships with their mothers who become obese.

According to Sarah E. Anderson, who worked on the study said, the stress in childhood may be a long influence on children's brains.

"There is overlap in the brain that regulate stress and energy balance. This stress response can be associated with obesity through appetite regulation," says Anderson, from Ohio State University College of Public Health, in Columbus.

Meanwhile, dr. David Gozal, a child specialist who was not involved in the study, agrees with this finding. But he said, unhealthy diet, physical inactivity and sleep, tend to play a greater role related to obesity.

"What you see in adulthood is clearly the cumulative effect of what has happened before," said Gozal, of Comer Children's Hospital, Chicago.