This doesn't seem like a thing. In fact, being a larger person will generally provide you with more resonant space, which will create a deeper, more booming voice. That said, the difference is not huge based on body size.

If your air production increases (because you're not out of breath all the time, because you're in better shape), that's also a thing that can change your vocal quality. But your voice is mainly affected by the air-filled cavities in your respiratory system (chest, oral cavity, nasal cavity, sinuses) and your larynx.

I'm still early on my wright-loss journey, but I have a lot of years of vocal training. A 60-pound loss didn't change my voice at all, and based on some old recordings, the 150+ pound weight gain that got me here didn't change it much either.