A life free of all animal products can be good for your heart, blood sugar, and waistline. But CocaCola, white bread, french fries, Oreos, and Spicy Chili Doritos are vegan. Stanford University nutritionist Christopher Gardner says that many Americans opt for a vegan diet for ethical reasons rather than health concerns, and thus don’t fully consider the overall nutrition of the lifestyle shift. While study after study confirms the bodily benefits of plant-based meals, the research applies only to those who follow a balanced plan to the letter. When done carelessly, cutting out all animal products risks deficiencies in iron, B12, and calcium—nutrients we typically get from meat, seafood, and dairy. Vegans have an increased risk of osteoporosis later in life, and, in the short term, too little B12 can cause weakness and fatigue. If plant eaters take the proper approach, they can get the nutrients they need from produce such as beans, broccoli, and leafy greens—without the need for artificially fortified processed foods such as breakfast cereals and nut milks. But, Gardner says, that rarely happens.