It’s easy to get stuck in a nutritional rut, eating the same foods over and over. But a narrow diet can be bad for your health. Here are three reasons why you should mix up what you eat.

1. Inflammation

“I see so many patients limit their diet because they’ve read something about removing this or that because it’s good or bad,” says Brigid Titgemeier, R.D.N., who specializes in functional nutrition. She explains that from an autoimmune standpoint, if you’re eating the same things over and over, your body has the potential to develop antibodies against those foods, which in turn can create a more inflammatory response and lead you to then react negatively to those foods.

2. Gut Bacteria

Limiting your diet decreases bacterial diversity in your intestines. “I like to use the analogy of a strong infield and outfield in baseball, with good hitting and good playing on the field,” says Titgemeier. “If you don’t have enough talent in each position, things will go wrong. It’s the same with your gut bacteria. You need a diversity of bacterial strings to do different things for good health.”

3. Weight Loss

More diversity in your tummy can also keep you at a healthier weight, says Titgemeier. According to a 2016 study of twins, those with a more broad diet had a lower percentage of abdominal fat and heart disease. Particularly significant in the findings was the lower levels of abdominal fat in twins with a more diverse diet. Additional research reported in the Yale Journal of Biology and Medicine has identified the role that gut bacteria may have on a person’s metabolism.