The article links to another article in the fourth paragraph. The use of the word seem implies we don't exactly know why.

"That’s because decades of agricultural research has shown that antibiotics seem to flip a switch in young animals’ bodies, helping them pack on pounds. Manufacturers brag about the miraculous effects of feeding antibiotics to chicks and nursing calves."

The above raises the question, do antibotics increase the BMI of human children long-term ? According to this article[1] the answer is yes.

[1] https://www.jhsph.edu/news/news-releases/2015/children-who-t...

This has been known for quite a while. I'm sure you could come up with quite a few sources if you really wanted to, though I'm not sure how well the phenomena has been studied (seeing as we still don't know what causes it).

An answer to your question was already in an immediate sibling subthread half an hour before you posted: https://news.ycombinator.com/item?id=17162574

Seriously this trend on HN to knee jerk react with "do you have sources for xyz" needs to stop. Googling it in 5 seconds will give you plenty of sources. Do your own research.

Aviv isn't just telling you not to be lazy. The observations that someone includes when they are trying to confirm their hypothesis are scientifically meaningless. Observations are only valid when they are made with good faith effort to discredit the hypothesis. This includes the meta-observations of going out and finding studies on the internet.

Lol that's such an aggressive response, no wonder HN has such limited success