I know someone like that. She was gaining weight while her daughter was losing weight - same diet, same walks everyday to hold each other accountable. It just didn’t make sense.
She finally confessed to having chocolate in her nightstand drawer. Lots of chocolate, and constantly replenished.
In high school I was at the home of a very overweight classmate. I was hanging out with her and another friend. She left the room for a moment and we noticed some candy bars on the floor by her bed. We took a closer look and underneath the bed was stockpiled with candy.