Being overweight or obese puts a person at greater risk for a wide variety of serious health problems. Obesity is recognized as a national problem that has grown tremendously over the last three decades, contributing to increases in medical expenditures for treatment of related diseases.

In 2016-18, 69% of residents in Lancaster County were either overweight or obese, which was higher than the state and nation (both at 66%). The counties' percentage was up 3 percentage points from 2011-13. Pennsylvania's rate increased by 1 percentage point and the U.S. rate decreased by 2 percentage points during the same period.

The percentage of overweight and obese residents in Lancaster County in 2016-18 was higher than in all the comparison counties, with the exception of Berks/Schuylkill at 73%. Of the comparison counties, Chester County had the lowest percentage of overweight or obese residents at 56%. Like Lancaster, Berks/Schuylkill and Cumberland/Perry counties saw increases in the percentage of overweight and obese residents since 2011-13, up 7 and 3 percentage points respectively. Chester County saw a decrease of 3 percentage points and both Dauphin/Lebanon and York saw a decrease of 2 percentage points in the same time period.

Data come from a federal government survey designed to collect scientific data on health risks and behaviors. The data reported are for moving three-year averages. Berks and Schuylkill county data is combined by the survey and reported together. Similarly, Dauphin and Lebanon counties and Carbon, Lehigh, and Northampton counties are reported as groups of counties.

Beginning in 2011, the Centers for Disease Control made two changes to the Behavioral Risk Factor Surveillance System on which this indicator is based. The survey now includes cell-phone users, and a new statistical method is used to weight responses. As a result, changes from 2010 and years prior to 2011 and later may be a result of those technical changes rather than true trends.