Leptin is a hormone that contributes to appetite regulation and satiety. There is some data that show that individuals with Down syndrome have increased leptin levels which correlates with higher rates of obesity. This is consistent with reports of family members and caregivers who have shared that their loved ones with Down syndrome never seem to get full.
Monitoring and managing portion sizes may help individuals with Down syndrome reach or maintain a healthy weight.
Source: Advocate Medical Group Adult Down Syndrome Center