be (a bit) on the heavy side

This intentionally vague phrase highlights the speaker's awareness of or hesitation about the weight of something or someone.

1. To be rather heavy, as of an object. Be careful moving that bookshelf, guys—it's on the heavy side! Hey, that tray is a bit on the heavy side, so be sure to carry it with two hands! Will you help me move this planter? It's a bit on the heavy side, and I want to put it near the front door.

2. To have some amount of excess body fat, as of a person. Emma used to be a bit on the heavy side, but she's lost a lot of weight since she started going to the gym regularly. A: "Wait, these are your pants? But they look too big for you." B: "Well, I was on the heavy side not too long ago. A: "That's Frank? But I remember him being a bit on the heavy side." B: "Yeah, it seems he's lost weight since he started cancer treatment."