We all know that it’s a good idea to cut back on red meat. Now a new study finds the kind of meat you eat makes a big difference. The research published in the journal Circulation shows eating processed red meat -- such as hot dogs, bacon, sausage, and cold cuts -- is linked to an increased risk of heart disease and diabetes.

But the study shows no such link for unprocessed red meat.

Eating one serving a day of processed meat -- or the equivalent of a single hot dog or two slices of salami -- was associated with a 42% increased risk for heart disease and a 19% increased risk for diabetes.

Eating unprocessed beef, pork, or lamb was not linked to a higher risk. The study is the largest research review ever to attempt to tease out the health impact of eating processed vs. unprocessed red meat. Both types of meat contain similar amounts of fat and cholesterol, but processed meats contain about four times more sodium and 50% more nitrate preservatives.

The finding has important implications for public health. The researchers advise that eating processed meat once a week would be fine. And they caution that this study should not be taken as license to eat unlimited amounts of unprocessed red meat.