Apologizes for the poor wording. Let me try again:
Since those who are condemning sleeves to the elbows are basing their argument on historical practices, I must ask if any of you follow the old Lenten fasting and abstinence laws of no meat and diary for 40 days and nights. Now the Church allows one meal for meat and all can include diary.
I would argue this a concession just like the one regarding shorter sleeves. Yet the Church tolerates it.
That's not a fair comparison, because modesty pertains to the Natural Law. Fasting pertains to Church Law.
I view it as Providential that more dense food is allowed than before, because with the Industrial Revolution and modern technologies, soils have become so depleted that food does not nourish as it used to.
If you speak to people who grew up on wholesome farms with mineral-dense soils, they will tell you that vegetables can be quite filling, while mainstream grocery store vegetables do not come close to being satiating.
As a result, my point is that the amount of discipline or self-denial it takes to fast today as opposed to back then is probably not much different.