If you’re trying to lose weight, and you have already given strong consideration to the foods you eat on a regular basis, you’re off to a great start. According to a report from Healthline, however, a new study suggests that there may be more to dieting than simply bumping up your intake of fruits and veggies.

The study suggests that gut bacteria can significantly influence the way we digest food, and what you choose to eat has an effect on this microbiome. It looked closely at people with diabetes, and found that gut bacteria can have a serious effect on a patient’s overall health.

The study offers insight into why traditional diabetes treatments work well for some and not so much for others. Doctors recommend eating more complex carbohydrates and fewer simple carbohydrates, and gut bacteria may be the secret behind why this treatment is more effective in some people than others.

The glycemic index is the most standard way to categorize foods as being safe of not safe for people with diabetes or prediabetes. People also the index to help plan weight-loss diets, using it to distinguish between “good” and “bad” carbs. The index tracks the amount of glucose various foods cause the body to create.

The study, published in the journal Cell, suggests that these average values in the glycemic index are not as helpful as many people believe. Foods with low glycemic averages, like lentils, can cause unexpected bursts of blood sugar production, while some traditionally “bad” foods, like ice cream, can actually be beneficial in certain cases.

According to Dr. Eran Elinav, a researcher from the Weizmann Institute of Science in Israel, “This variability is something that can explain some or all of the general failure of the human race to apply a universal diet to address the obesity epidemic.

A press release outlining the details of the study can be found here.