It’s easy enough to fall into a routine when you have a busy work week to deal with, even when it comes to food. But your every day bagel for breakfast, sandwich for lunch and meat and salad for dinner can do you a lot of harm, even if it does save you from the meal planning part.

“More food variety universally leads to more food intake,” Susan Roberts, director of the Energy Metabolism Laboratory at Tufts University, told Time. According to Roberts we’re “hard wired” to go for variety when it comes to food.

“No one food has all the nutrients we need in the optimum amounts, so eating a variety of foods means you are much more likely to get enough of each one,” she added.

A study showed that women who ate over 16 to 17 items from a list of healthy foods reduced their risk of dying from any cause by 42 percent when compared to women who had less than nine items from the list.

Bad to eat the same thing every day People who eat the same food over and over again are likely to be less healthy than those who eat a variety of food. CATE GILLON/GETTY IMAGES

Another study found that people who ate the same food over and over again were likely to be less healthy than those who ate a variety of food.

Researchers said that compared to people who stick to the same foods, those who consumed a variety of foods were 21 percent less likely to develop metabolic syndrome, a cluster of health conditions including high blood pressure, high blood sugar and increased body fat which increases chances of developing heart disease and diabetes. People who eat a wide variety of foods are also likely to have a healthy waist circumference.

Eating a variety of foods also promotes greater bacterial diversity in your gut and this diversity can be instrumental in keeping your weight in check while keeping several health conditions at bay.

“Each type of food and micronutrient seems to have a [bacterial] specialist that can utilize it. So maybe the best diet has a little bit of everything,” Mark Heiman, vice president and chief scientific officer at the biotechnology company Microbiome Therapeutics, reportedly said.

So the best thing to do is to hit all the major groups—fruits and vegetables, whole grains, low-fat dairy, lean protein and good fats on most days. You can alternate between the different items in each group.