Abstinence and fasting (Catholic traditional definition is one big meal, or a couple small meals) are sacrifices. They&#x27;re also not sustainable (ok, maybe abstinence from meat, plenty of healthy vegetarians, but not fasting) over a long period if a population actually has to do any significant physical labor. Once a week makes it more significant than once or twice a year, but not so impactful as to prevent people from remaining otherwise high functioning (physically and mentally).<p>Also, Meatless Monday is not about concern for the animals. It started as a health concern, and morphed into an environmental concern. If the concern were for the animals, they should be going for full-time meatlessness.<p><a href="http:&#x2F;&#x2F;www.jhsph.edu&#x2F;research&#x2F;centers-and-institutes&#x2F;johns-hopkins-center-for-a-livable-future&#x2F;projects&#x2F;MMP_old&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.jhsph.edu&#x2F;research&#x2F;centers-and-institutes&#x2F;johns-h...</a><p>EDIT:<p><a href="http:&#x2F;&#x2F;www.meatlessmonday.com&#x2F;the-global-movement&#x2F;" rel="nofollow">http:&#x2F;&#x2F;www.meatlessmonday.com&#x2F;the-global-movement&#x2F;</a><p>In reviewing the above link, it seems that Meatless Monday has been brought to numerous countries by various groups. The two primary motives seem to be about health and sustainability. There are, however, some countries where vegetarian groups brought it in, I imagine as a way to get more people implementing a partial practice of what they want, a more politically savvy way to move things where they want rather than insisting on 100% vegetarianism <i>today</i>.