Vexillology

But the idea is that there are sacrifices people make as an observance of faith.

The ideas of tithing and shows of humility and pilgrimage were more than just observations of faith. They were cultural patterns of behavior intended to build social cohesion. The building of a shared identity through communal offering and collective participation in events isn't unique to religion. In the modern era we pay taxes and celebrate national holidays and travel to places of historical significance in an ostensibly secular consequence. But all of this mirrors (and much of it is predicated by) patterns within religious institutions.

Right now during Lent millions of people have chosen to give up something as a religious ritual.

Sure. And during Meatless Monday millions of people have chosen to give up something as a secular ritual.

As the costs (both financial and ecological) of meat consumption rise, a secularized ritualization of eating more "humble" meals could provide significant benefits. And there's a certain degree of irony in religious conservatives seeing that more clearly than secular liberals, as AM radio talking heads go into apoplexy over Veganism as some kind of heresy in the Cult of the Burger.

If the government banned the sale of caffeine during Lent, then my choosing to go without it for a month wouldn’t have any impact

It would have an enormous impact... to Starbucks. That's why its very unlikely to happen.

Similarly, you won't see too many major news networks platforming an LDS Pastor who advocates prohibition on caffeine. Hell, you won't see too many daytime talk show heads who warn the health hazards of ground beef. Not after the Oprah Winfrey lawsuit in 1996.

But if state officials could decouple themselves from the corporate cronies that are fixated on quarterly profits above all else, would I really cry over a designated National Day of Abstaining From Burgers and Coffee? No.