People who make their own meals at home are less likely to develop diabetes than those who frequently eat out, a study shows.

Harvard T.H. Chan School of Public Health researchers evaluated large prospective datasets in which U.S. health professionals (both men and women) were followed for long periods on a variety of health indicators. In fact, they analyzed 2.1 million years worth of data.

Among their discoveries was that eating home-cooked dinners 5 to 7 times a week translated to a 15 percent lower risk of Type 2 diabetes compared to people who did so twice a week or less.

There was a smaller, but still statistically significant, reduction for people who ate more home cooked midday meals, said the researchers. The study appeared in PLOS Medicine’s special “Diabetes Prevention” issue.

I always recommend that patients prepare and cook their own meals. It’s only by doing it yourself that you can control nutritional — and caloric — content.