No wonder social media feeds are packed with pictures of overflowing smoothie bowls: It appears people feel the types of foods they consume play a bigger role in their health goals than the volume they eat. As a result, a study from Vanderbilt University published in Management Science suggests that those who are trying to maintain a healthy body weight or wishing to shed a few pounds might be prone to overeating “healthy” items like nuts, granola and avocados. The upshot: The public should be educated about practicing portion control—for foods of all kinds.