A new study has found that people who live in countries where the weather is good and there are more natural features like hills and lakes are more active and thinner.
The findings do not prove that natural features affect how much exercise people get or how much they weigh, but it does raise questions that further research can explore.
"We're trying to figure out whether the places themselves encourage activity or people who want to be active move to these places," said lead author Stephanie Jilcott, an assistant professor at the Department of Public Health at East Carolina University.
She added that such research could encourage discussion about how to better link people with natural amenities - like lakes - that could boost their physical activity.
The study authors examined statistics about the average weight of residents in 100 North Carolina counties and tried to link them to rankings of the weather and the presence of natural features like lakes and hills.
The researchers adjusted their statistics, compiled from 2000 to 2007, so that factors like poverty level, participants' age or the percentage of rural and African-American residents in each county would not throw off the results.
Body mass index (BMI) is a measurement used to determine whether people are overweight. In adults, normal BMI is 18.5 to 24, while experts consider 25 to 29.9 to be overweight and 30 and over to be obese.
For the study, Jilcott said, the average body mass index was 0.47 points higher in counties with the lowest natural amenity scores compared to those with the highest. This might not make much difference to an individual, she said, but it is more significant in total across a community.
However, the statistics in the study did not offer a breakdown of how many exercised in, say, a gym instead of outside.
"There's nothing we can do to change the natural environment. It is what it is, but county leaders may want to assess what elements of natural amenities that could be enhanced," Jilcott said.
"For example, if the county is flat, but has access to water, parks and recreation departments could attempt low-cost investments in encouraging residents to be active in and around the water," she added.
The results appear in the September/October issue of the American Journal of Health Promotion.