I'd Google their names. Invariably those thirty-somethings were very overweight, most likely obese.
This is not weight shaming, just observation. I'm someone who has struggled with my weight for a very long time. Last summer I started cutting way back on my food intake, and had dropped at least 35 pounds by the time I had a heart attack in December. I've since lost another 20 pounds. More to the point, my BMI has gone from over 31, the start of obesity, to 23, well within the normal range.
I've had to buy new clothes, not a problem since I dress quite casually and so my new clothes aren't at all expensive. Right now I weigh less than I have in decades, before I got pregnant with my first child. It feels good.
More recently the continued weight loss has been helped by having major oral surgery back in June, having all of my teeth extracted and wearing dentures, which still are needing refitting. Honestly, while this has been a sort of boon to my weight loss because eating is sufficiently unpleasant that I tend to avoid it, I would not recommend this to others.