This is especially true when the people giving recommendations aren't actually nutrition professionals, which is unfortunately often the case on social media. On Instagram, anyone can call themselves an "expert" or "nutritionist," when they don't have any education or credentials, McMordie says. If you're looking for nutrition information, you should be consulting a registered dietitian (RDs or RDNs) or anyone with an advanced nutrition degree, she says. When registered dietitians work with clients, they take the person's medical history and lifestyle factors into account before they make any recommendations, she says. "There are so many conditions that are affected by diet, so it's best to consult a doctor or dietitian when making a big change to your diet," she says. And a PDF simply can't do that.