This has been known for a very long time and is definitely not news worthy

This was only proven by Pontzer and others with double labelled water studies when the cost of double labelled water went down enough for testing with humans to become affordable. Initially it was so expensive that only trials with a few small animal subjects were done so doing this large study was impractical until recent years. https://www.sciencedirect.com/science/article/pii/S000291652...