The Minnesota Coronary Study provided investigators complete control over patient diets for nursing home patients over 3-4 years.

“so for example the Minnesota coronary study was a seven year study that was uh well I shouldn't say that it was I think the actual intervention was probably closer to three or four years I could be wrong on that um but it was done on patients in a nursing home and you know there you had the interesting situation where you had patients who were relatively old therefore at high risk for ascvd but the investigators had complete control over what those patients ate because every meal was being provided to them”