Compared with being vegetarian or mostly vegetarian, it is. One must pay much more attention to their diet and intake. In addition, most folks need to take supplements. As the other response said, it is also harder to eat out. Vegetarian is much easier - the addition of things like eggs and cheese helps out tremendously. I read ingredients, sure, but it isn't an issue most times. It would take more mental work to keep out all animal products.

I might be mostly vegetarian and eat eggs and cheese and fish once a week, but I usually tell folks to reduce their eat. Sometimes I say instead to make sure they eat enough fruit and veg and whole grain. I say this stuff because it is easier for most folks to concentrate on things like this to improve overall diet without feeling like they have to spend days figuring things out.