Neanderthals, owing to their body make up, required 5000 cal per day to maintain.
This is a much higher requirement then for modern man.
With the advent of the ice age, Neanderthals could not compete effectively for the calories that they needed.
“Neanderthals, owing to their body make up, required 5000 cal per day to maintain.”
I don’t buy the body make up bit. There was a show on TV that I watched which was very interesting, it was about the old time loggers who cut forests with axes and two man saws, these were the men who gave rise to the legend of Paul Bunyan. Interestingly it was said that the average logger of that time was around five seven or eight and weighed around one hundred and fifty five pounds. They were said to have consumed an average of around seven thousand calories daily, that is considerably more than your figure for the Neanderthal who were to my knowledge heavier boned than modern man. I have spent many long days cutting wood with an axe and pulling one end of a two man saw in my teen years so I have some knowledge of the subject. Anyone doing really hard work is going to need to consume three to five or maybe even more times as many calories as someone who works at a desk and does little else. Five thousand calories for one day is NOT a huge amount for someone doing real physical work. Neanderthals may not have worked as hard as loggers but I am sure they did not have a physically easy life.