Not everything has to be “functional,” you know.

It’s no coincidence that soup is just what the doctor ordered for when you’re feeling under the weather. In most cases, a big ol’ bowl of chicken noodle is packed with the necessary, nutrient-rich ingredients to help support immune health and get you back up and running in no time.

But with so many options to choose from on the menu—minestrone, vegetable, broccoli cheddar, the list goes on—what’s the best soup for when you’re sick? We caught up with two registered dietitians that share their comprehensive guide to choosing the best soups (homemade or store-bought) for feeling better in no time. Spoiler: They’re soup-er tasty, nourishing, and have one thing in common—lots of protein.

What is the best soup to eat when you’re sick?

According to Melanie Murphy Richter, MS, RDN, a registered dietitian and neuronutritionist, soups have been helping folks get over colds for ages. “Dating back to the 5th century BCE, soup was used to supply a substantial amount of nutrients from herbs, vegetables and meats—or even the bones of animals—into an easily digestible broth or liquid,” she says.

Richter says what makes a soup ideal to eat when you’re sick boils down to the amount of vitamins, minerals, and, most importantly, protein it provides. According to her, protein is the number-one vital ingredient necessary for when you’re under the weather. “When we are healing from anything, our daily protein requirements—aka the building blocks of our entire body—increase, as do our need for certain minerals like zinc, selenium, iron, magnesium and sodium, to name a few,” Richter says. “Finding a soup that is high in protein will ensure you are getting the much-needed repair of protein.

That’s a main reason why Richter often relies on bone broth when making the perfect homemade soups for a quick recovery. “When I make soup at home, I typically use bone broth because of its high protein and mineral supply,” Richter says. For an even heartier combination Richter pairs the broth with low FODMAP vegetables for easier digestion to make her go-to “Ultimate Healing Soup” (recipe ahead). Best part? It’s ready in no more