But even in Colorado, known as the Rocky Mountain state and prized for its outdoor lifestyle, obesity crept up from 18.4 to 18.7 per cent.
In 1980, the average of obese adults across the United States was 15 per cent.
The report blames the upward trend on a number of factors, including the fact that Americans consume an average of 300 more calories per day than they did 25 years ago, eat less nutritious foods, and jump into the car even for trips of less than 1.6 kilometres instead of walking.
Meanwhile, the percentage of obese and overweight children aged 10-17 was at or above 30 per cent in 30 states, the report said. In no state was childhood obesity lower than 20 per cent.
The worrying trend among children is blamed on poor diet, unsafe or poorly maintained outdoor spaces, and too much time spent in front of the television, computer or games console - activities that also eat into the time that kids could be active.
Obese children are at higher risk of developing heart disease, high cholesterol and type 2 diabetes, and they are more likely to become obese adults, who are at risk from the very same health problems.
'The childhood obesity epidemic is putting today's youth on course to potentially be the first generation to live shorter, less healthy lives than their parents,' the report said.
It urged action on the national, state and community levels to fight obesity, but warned that the United States was way off target to meet a goal set by the Department of Health and Human Services of slicing the obesity rate in all 50 states to 15 per cent by next year.
'Clearly that goal will not be met,' the report said. -- AFP