The study, published in the journal Cell, also uncovered dramatic long-term consequences of an overly aggressive immune system. A diet too high in sugar and fat may be doing permanent damage to your body’s immune cells, putting you at a greater risk for type 2 diabetes and arteriosclerosis in the future.

To conduct the study, scientists switched mice from a typical grain diet to a “Western diet” that was high in sugar and fat, and low in fiber, for one month. The scientists noticed an unexpected finding—a sharp increase of immune cells in the blood of the mice.

To find out what was happening, the scientists compared the immune cells of mice from the study with a control group on a healthy diet. The mice on a fast food diet had significantly higher levels of granulocytes and monocytes, or progenitor cells that work to repair the body during infection.

Essentially, an unhealthy diet triggered an inflammatory response in the mice, the same response caused by a bacterial infection.

After allowing the mice to return to their typical diet, scientists discovered more unsettling findings. While signs of acute inflammation had disappeared in the mice, the genetic reprogramming caused by a poor diet remained. In the mice, just one month of junk food pointed to lasting, long-term health effects.

"It has only recently been discovered that the innate immune system has a form of memory,” explains Professor Dr. Eicke Latz, director of the Institute for Innate Immunity of the University of Bonn and scientist at the German Center for Neurodegenerative Diseases. “After an infection, the body's defenses remain in a kind of alarm state, so that they can respond more quickly to a new attack."

According to the study, when your body’s immune cells remain in an aggravated state, you are more at risk for type 2 diabetes, heart attack, or stroke in the future.

Lastly, the study strongly encouraged early education as a preventative measure against the dangers of fast food. "The foundations of a healthy diet need to become a much more prominent part of education than they are at present,” asserted Latz. “Only in this way can we immunize children at an early stage against the temptations of the food industry.”

So, what can you do to help your kids form lasting healthy food habits? An easy place to start is to cook more healthy and kid-friendly recipes at home. Involve your kids as much as possible, whether it’s taking a trip to the farmers’ market or grocery store, so they’ll learn to appreciate the value of whole, nutrient-packed ingredients at a young age. If you can prove to your kids that delicious food doesn’t have to come from a drive-through window, they’ll be more likely to make healthy eating a habit for life.