HuffPost: California Becomes The First State To Prescribe Food As Medicine
This article doesn't specifically mention a plant-rich diet, but chances are many of these tailored diets emphasize vegetables, beans, fruits, etc. Pretty miraculous.
"They found that recipients of these free meals had average monthly medical costs that were 55 percent lower than Medicaid patients who didn’t get delivered meals. Hospital admission and duration rates were also significantly lower than the control group. Most strikingly, people who received meals from MANNA and were later hospitalized were 23 percent more likely to be discharged back to their homes as opposed to a long-term care or rehabilitation facility when compared to the control group."