MOST OF US don’t spend much time thinking about joint health. We are more interested in getting that perfect bicep peak or beefing up those quads. But cartilage and joints are important (obviously), and working out has been shown to strengthen them, so you should have resilient joints as you age if you keep up the workouts. But a recent study from the Queensland University of Technology in Australia says you also need to drop the bad eating habits if you want to keep from having deteriorated cartilage—aka osteoarthritis—once you reach retirement age.

For the study, researchers tested a bunch of diets that were rich in saturated fats like butter, coconut oil, palm oil, and animal fat along with simple carbs—the components of your basic junk food or fast food diet. “Our findings suggest that it’s not wear and tear but diet that has a lot to do with the onset of osteoarthritis,” said study lead Yin Xiao, Ph.D. “We found that a diet containing simple carbohydrates together with 20% saturated fats produced osteoarthritic-like changes in the knee.”

Cartilage is a tough, elastic-like tissue that covers the ends of your bones and helps absorb the forces put on bones during weight-bearing movement like walking and running. “[But] saturated fatty acid deposits in the cartilage change its metabolism and weaken the cartilage, making it more prone to damage,” said Xiao. “This would, in turn, lead to osteoarthritic pain from the loss of the cushioning effect of cartilage. We also found changes in the bone under the cartilage on a diet rich in saturated fat.”

If you value being mobile and able to easily walk and run around, don’t wait until you are reaching the age where your joints start to ache and creak—change your diet now and head for whole fresh foods, and drop the greasy fast food and carb-loaded, packaged snacks. To create a healthy diet and feed your cartilage what it needs to be strong and healthy for many years to come, check out the plan below.