Overweight seniors cost more under Medicare than their thinner counterparts, a new study finds.

The journal Health Services Research found that, over the course of their enrollment in the Medicare program, heftier seniors required an additional $15,000 to $26,000 worth of treatment than those beneficiaries at a healthy weight. Researchers at Emory University interpreted the data collected from the Medicare Current Beneficiary Survey from 1992 to 2001 to determine the relationship between a senior’s weight and his or her medical expense requirements.

A separate recent study from the Centers for Disease Control and Prevention found that seniors in general are among the skinniest subset of the adult population. An average of 25.6% of all adults are reported as being obese, compared to 19.4% of seniors over 70, according to that report.