Bill Clinton’s recent announcement that he has gone vegan raised more than a few eyebrows. After all, the thinking went, how could a man whose name once conjured images of french fries and Chicken McNuggets possibly subsist on a diet of plant-based foods?

No doubt the former president’s health problems, which included a quadruple bypass surgery in 2004, made him reaccess his dietary choices. But as The Wall Street Journal Health Blog points out, making the switch to vegan fare is no guarantee of proper nutrition.

Despite the less desirable health aspects of meat and cheese, they do provide necessary nutrients that aren’t as readily accessible in plant-based food. Registered dietician Dawn Jackson Blatner identifies four general groups of nutrients that vegans should be sure to get enough of:

• Calcium and vitamin D – Most people get these through dairy products. Vegans can get their allotment in soy and almond milk, orange juice, and whole wheat bread.
• Protein, iron and zinc – Since steak is no longer on the menu, vegans should opt for plant-based foods including beans, nuts, seeds and soy products including tofu and tempeh.
• Vitamin B12 – Difficult to find outside animal products. Blatner recommends looking for fortified products like plant milks, as well as some cereals and a form of nutritional yeast.
• Omega-3 fatty acids – Typically found in fish, but they can also be gotten via walnuts, flaxseeds and chia seeds.