Bill Clinton's hamburger days are behind him, he says.

The former president now thinks of himself as a vegan, he tells CNN's Sanjay Gupta, eschewing meat, dairy and eggs. (No word on whether he's traded recipes with fellow Democrat and vegan Dennis Kucinich.)

Clinton adapted a plant-based eating pattern out of concern for his cardiovascular system -- "to avoid any food that could damage his blood vessels," CNN says. If you've considered going the same route, though, you should know that while a vegan diet can certainly be healthful, it has to be done right.

There are four general groups of nutrients that vegans should be sure to get enough of, says Dawn Jackson Blatner, a registered dietitian based in Chicago and author of "The Flexitarian Diet." Most people get calcium and vitamin D through dairy products, so if you're skipping those, look for fortified plant-based drinks like soy and almond milk or OJ, as well as foods. (Here are some food sources of calcium.)

Vegans can get protein, iron and zinc, meantime, from plant-based foods including beans, nuts, seeds and soy products including tofu and tempeh, Blatner says.