“When you feel terrible, managing your diet falls to the bottom of your list,” said Karen Pearl, the president and chief executive of God’s Love We Deliver.

The California study will build on more modest and less rigorous earlier research. A study in Philadelphia by the Metropolitan Area Neighborhood Nutrition Alliance retroactively compared health insurance claims for 65 chronically ill Medicaid patients who received six months’ of medically tailored meals with a control group. The patients who got the food racked up about $12,000 less a month in medical expenses.

Another small study by researchers at U.C.S.F. tracked patients with H.I.V. and Type 2 diabetes who got special meals for six months to see if it would positively affect their health. The researchers found they were less depressed, less likely to make trade-offs between food and health care, and more likely to stick with their medications.

Their care also cost less: the price of feeding each participant for six months was $1,184 per person, less than half the $2,774 cost per day at a California hospital, according to the study.