Fruit and Book

Food as Medicine: Great Program, but Lacking a Medical Benefit

Food as medicine programs can yield a fantastic medical benefit, say the promoters of this currently trendy concept in nutrition policy. If implemented broadly, they “would save lives and billions of dollars.” That’s the word from Tufts, where Dariush Mozaffarian is selling this concept with great enthusiasm. The whole idea behind these claims is that they would surely prove true if only we could expand produce prescriptions nationally for people with diabetes and food insecurity.

But there’s one little problem with those promises. A new randomized controlled study of food as medicine for people with food insecurity and type 2 diabetes found no benefit for clinical control of diabetes. JAMA Internal Medicine published the study yesterday.

An RCT of 465 Patients

This was a randomized controlled study of a very intensive food as medicine program with weekly clinic visits to receive healthy groceries and receive counseling from dietitians. The control group went on a waiting list for the program. The duration was one year.

The improvements from baseline in the program were great. Glycemic control improved and people engaged more with preventive healthcare. They got more prescriptions for metformin and GLP-1 medicines.

But glycemic control improved in the control group, too. So there was no medical benefit for in the targeted problem, type 2 diabetes. The lead author of the study, Joseph Doyle, told MedPage Today that these were surprising findings:

“I was surprised by the findings because the program is so intensive. The health system built brick-and-mortar clinics, staffed them with a dietitian, nurse, and community health worker, had weekly food pick-up for 10 meals per week for the entire family, and participants spend a year in the program.

“The program inspires its participants, and we found it increases their engagement with healthcare, which we expected going in. I would have expected that this would have improved the primary measure of diabetes interventions, HbA1c, more compared to a group that did not have access to such a program.”

The Importance of a Control Group

In an editorial comment published with the study, Deborah Grady underscored the importance of controlled studies for programs such as these:

“If this trial had been uncontrolled, the intervention would have been found effective. We believe that the wait list design used in this trial was optimal. The design provided a randomized comparison group that did not get the food intervention at the same time as the intervention group but still provided 6 months of healthy food at the end of the waiting period.

“Whenever possible, investigators should randomize interventions to avoid falsely concluding that pre- vs postintervention differences are due to the intervention.”

Surely, this is not the final word on food as medicine. Doyle cautioned that

“One study should not be over-interpreted. It is possible that such a program could work in other contexts, among patients less connected to a health system, or in other formats.”

Just as Doyle is correct in making this point, it is also important that promoters of this trendy concept should not over-promise the benefits it might deliver.

Speculation is a poor substitute for evidence.

Click here for the study, here, here, and here for further perspective.

Fruit and Book, painting by Juan Gris / WikiArt

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December 27, 2023

6 Responses to “Food as Medicine: Great Program, but Lacking a Medical Benefit”

  1. December 27, 2023 at 7:35 am, Bruce Daggy said:

    While I’m skeptical of the practicality of scaling any intervention that is as hands-on and costly as this one, my takeaway from the results would be more that when subjects in both arms of the study substantially increased their use of diabetes medications, any effect of the dietary intervention became impossible to discern. Subjects in the intensive intervention arm may in fact have been better nourished — let’s hope so — but any benefits from that were not apparent in the study’s primary outcome measures. Didn’t Novo had a similar result in a large trial of a GLP-1 drug, where adding IBT failed to significantly improve weight loss outcomes? It’s like trying to detect the effect of a following wind on the speed of a Lamborghini. The signal may be there, but it’s lost in the vroom-vroom..

    The typical American diet is problematic and there is no easy fix for this. The food supply that would result in better health outcomes — assuming people would prepare and eat it, a big assumption — does not exist at scale.

    • December 27, 2023 at 7:42 am, Ted said:

      Good insight, Bruce. Thanks!

  2. December 27, 2023 at 8:33 am, Tom Rifai MD FACP said:

    This study is a good learning lesson but hardly the final word. Intervention arm gains weight? The meals are not fully prepared? Campbell’s ran RCTs of fully prepared and delivered meals in the 90’s and the results were quite different, including achieving weight loss – a result without which (esp in a trial of full or pre type 2 diabetes) smells of problematic devils in the details.

    The DPP and Look AHEAD RCTS (of those with prediabetes and type 2 diabetes, respectively) – totaling over 8000 participants, revealed clear benefits when intensive lifestyle counseling was provided and weight loss achieved using meal replacements – including recent 20y follow up of the Look AHEAD group losing 10% or more of their body weight in year 1 achieving a 20% mortality risk reduction 20 years later.

    I wouldn’t consider this 2023 JAMA study more than a reveal of weaknesses to be addressed in the next ‘food is medicine’ trials. But a very valuable and insightful set of weaknesses which couldn’t have been learned without the effort, to which I give kudos and thanks.

    • December 27, 2023 at 8:58 am, Ted said:

      Yes indeed. This is neither the final word, nor affirmation of hyperbolic claims about “saving lives and billions of dollars.”

      But it’s best to be careful about claiming a “20% reduction” in mortality risk due to the Look AHEAD lifestyle intervention. The investigators had an entirely different conclusion:

      “In conclusion, Look AHEAD found no statistically significant difference in all-cause mortality over a median of 16.7 years of follow-up in ILI compared with control. There was some evidence that those in ILI who lost 10% of their body weight at 1 year had lower subsequent mortality.”

  3. December 29, 2023 at 1:00 pm, Rick Lee said:

    Tom Rafai is right on: the test is will the dogs eat he dog food. In such tests, dogs are never provided with raw ingredients and asked to do their own food prep. This RCT relies on food prep to precede food consumption. In my company, we deliver 14 prepared meals each week that require 3-4 minutes in a Microwave. When nutritional intake is made easy, food as medicine is a game changer.

    • December 30, 2023 at 6:53 am, Ted said:

      I note your comparison of people targeted in food as medicine programs to dogs. You lost me right there.