When I still lived with my parents and was in high school I would see the same guy huffing his way down the road. Really big guy, you could tell he was struggling and miserable and losing motivation so I honked at him and yelled something along the lines of “you got this bro don’t give up”. I waved at him, gave him a thumbs up or just grinned at him every school day. By the end of the school year he went from obese to slightly chubby (but still shrinking). I ended up buying him coffee and chatting for a while. He told me that me encouraging him on that first day and acknowledging him every day after had been a factor in his not giving up since his family was pretty unsupportive and thought he would give up quickly.