Many consider veganism to be an exercise in self-denial and self-sacrifice, but the opposite is true: Using animals and consuming animal products is an unjust and often violent taking. To consider veganism a sacrifice is to believe that we have a right to use and abuse animals any way we choose. Veganism cannot be a sacrifice because it's not about giving up meat, eggs and dairy; it's about not taking someone else's life and liberty.
More simply, it's not a sacrifice to give up something that wasn't ever rightfully yours.
Dictionary.com defines sacrifice as "the surrender or destruction of something prized or desirable for the sake of something considered as having a higher or more pressing claim." The implication is that the prized or desirable thing being surrendered belongs to the person making the sacrifice. It can't be a sacrifice to surrender someone else's prized or desirable possession.
No one claims that obeying the law is a sacrifice. Refraining from assaulting, raping or murdering people is never considered a sacrifice. Similarly, refraining from taking another sentient being's life or liberty is not a sacrifice.
There are other reasons veganism cannot be considered a sacrifice. Some believe that being vegan is difficult, but as Prof. Gary Francione explains, veganism is not a sacrifice because it's easy:
I became a vegan 24 years ago. It was not particularly difficult back then but it is absolutely absurd to characterize it as difficult today. It is easy to be a vegan. Sure, you are more limited in your restaurant choices, particularly if you do not live in or near a large city, but if this inconvenience is significant to you and keeping you from being vegan, then you probably were not serious about the issue anyway.
Veganism is also healthy, so one's health is not sacrificed. The American Dietetic Association supports vegan diets:
It is the position of the American Dietetic Association that appropriately planned vegetarian diets, including total vegetarian or vegan diets, are healthful, nutritionally adequate, and may provide health benefits in the prevention and treatment of certain diseases.
Vegans also do not sacrifice delicious foods. A plant-based diet can include fruits, vegetables, beans and grains from all over the world. If one is interested in vegan meats, cheeses, ice creams and other sweets, there are more and more of these types of products hitting the market every day. It might take some time and effort to learn about vegan products, but any change in routine requires an adjustment period.
Vegans give up little or nothing in terms of convenience, health and gastronomy, but most importantly, veganism is not a sacrifice because it's not a sacrifice to give up something that never belonged to you.