Here's what researchers found.

Share on Pinterest Whether you’re trying to gain muscle, lose weight, or simply eat a healthier diet, different types of protein may help you reach your goals more easily. Henn Photography/Getty ...

Most of us prefer a bit of variety in what we eat. Not true for these five "specialist" species, who seem perfectly content relying on just a single type of food. Humans are, by nature, omnivores. Our ...