FOR ALL THE crap that vegans get, their diet can be quite good for you and good for the planet as it keeps you from eating foods heavy in fats and makes you indulge in more produce; plus, it reduces reliance on livestock for food, lowering the impact on the environment. But vegans can be a little rigid (and often insufferable) with their borderline-evangelical insistence on toeing the vegan line, which can lead to nutritional deficiencies and unhealthy practices if they aren’t up on proper guidelines.

Case in point is a recent presentation from the annual European Society of Paediatric, Gastroenterology, Hepatology, and Nutrition (ESPGHAN) meeting, which found that young kids who are on a vegan diet and not given proper medical and dietary advice are at a higher risk of having low levels of nutrients like vitamin B12, calcium, zinc, and protein. They also noted that, in general, children on a vegan diet are leaner and smaller than kids who eat meat or are even vegetarians.