I think both. Poor people died because of lack of nutrients and even calories, while the extremely rich died of gout and diabetes because of excess.
It seems the templar got all the nutrients they needed (feast on large amount of protein once a week, plant based diet the rest of the week) while using moderation most of the week and even a fast once a week.
They did a Lenten fast once a week, which is not usually the same as abstaining from food. From the article, it sounds like they were eating but not eating meat. However, note that fish is not considered meat for the purposes of Lenten fasting.
It is the same today... Catholics in my pueblo do not eat carne on Fridays (during Lent) which is to say no air breathing animal. Tuna fish salad is a very popular meal on Fridays if you have a house full of Catholics during Lent.
"So three times a week, the knights were permitted to eat meat"
those two paragraphs were a little scattered, but it's 3x per week... Definitely Sundays and then maybe Tuesday/Thursday, but sometimes one of those days was a fast.
It seems the templar got all the nutrients they needed (feast on large amount of protein once a week, plant based diet the rest of the week) while using moderation most of the week and even a fast once a week.