New York, Feb 5 (IANS): Obesity has significantly increased over the past three decades in both children and adults, a new study has found.

Children with childhood attention deficit hyperactivity disorder (ADHD) -- the most commonly diagnosed mental disorder of children -- are at a high risk of developing obesity during childhood and adulthood.

Females with childhood ADHD were at a two-fold greater risk of developing obesity during childhood and adulthood compared to females without ADHD, the study revealed.

Also, obesity was not linked with stimulant treatment among childhood ADHD cases, the findings showed.

"Females with ADHD are at risk of developing obesity during adulthood, and stimulant medications used to treat ADHD do not appear to alter that risk," said Seema Kumar, paediatrician and researcher at Mayo Clinic in Minnesota, US.

There is a need for greater awareness regarding the association between ADHD and obesity in females among patients, care givers and health care providers, the researchers stressed.

The study encourages all patients with ADHD to engage in preventive measures, specifically healthy eating and an active lifestyle, as part of routine care to prevent obesity, they added.

The research, published in the journal Mayo Clinic Proceedings, is the first population-based longitudinal study to examine the association between ADHD and development of obesity using ADHD cases and controls of both sexes derived from the same birth cohort.

The study included 336 individuals with childhood ADHD born from 1976 to 1982 and matched with 665 non-ADHD controls of the same age and sex. Weight, height and stimulant treatment measurements were gathered from medical records detailing care provided from January 1, 1976, through August 31, 2010.