Eating Cooked Meat Can Affect Kidney Test Results

Eating cooked meat can raise a person’s serum creatinine level enough to affect the estimated glomerular filtration rate (eGFR) classification and potentially lead to misclassification of chronic kidney disease stage in people with diabetes, according to a new study published in the journal Diabetes Care.


Diabetes is the leading cause of end-stage kidney disease, and accurately screening and staging chronic kidney disease is critical for guiding treatment decisions. Glomerular filtration rate is a test that determines how well the kidneys are working based, in part, on the level of creatinine (a by-product of muscle metabolism) in the blood.

To determine the effect of eating cooked meat on creatinine levels, researchers looked at 64 adults with either Type 1 or Type 2 diabetes and chronic kidney disease, with sixteen people in each of the four chronic kidney disease stage groups. Sixteen people who had neither diabetes nor kidney disease were also evaluated.

Participants were given one of two meals, each of which consisted of roughly 44 grams of either beef or plant protein. Blood samples were taken before the meal and at 1, 2, and 4 hours after, as well as the following morning after a 12-hour fast.

The researchers found that people with diabetes and kidney disease showed a statistically significant increase in creatinine levels after the beef meal due to the presence of creatinine in the meat. This, the researchers note, could lead to chronic kidney disease being misstaged by impacting the results of the eGFR.

Requesting people to fast prior to having eGFR and serum creatinine tests is one solution, but “from a clinical perspective, there will be a risk of hypoglycemia in insulin-treated patients,” noted study author Sunil Nair, MRCP. “The recommendation could be modified to [simply] avoiding cooked meat prior to blood sampling to measure renal function.”

The researchers next plan to investigate the use of alternate markers of kidney function that are not known to be affected by conditions such as protein consumption.

For more information, read the article “Eating Cooked Meat Can Distort CKD Stage in Diabetes” or see the study’s abstract in the journal Diabetes Care. And to learn more about preventing and treating kidney disease, click here.

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  • marylittle

    this is always good to know for sure i willmake sure i don’t eat meat before i go visit the nephrologist here on in thank you for this timely article for sure as there are many of us outhere who have no idea and are constantly working that national kidney foundation no no list as well as being diabetic!!

  • Helen

    Does this only pertain to beef? What about chicken and pork?

  • Becky

    That could explain the frightening stage three diagnosis I received a couple of years ago that was followed by a better result after a couple of following tests. I will keep this in mind when I have my next test and eat a vegetarian meal before I go in.

  • Bea

    My daughter passed away from diabetes destroying her kidneys a year ago March 2nd. . I wish we had known about this before.
    I also have diabetes and have been worried about this happening to me. Thank You for the article I found it very interesting and knowledgeable.

  • Diane Fennell

    Hi Helen,

    Thank you for your question. According to Dr. Nair, the same effect would be expected from chicken and pork, but there is not yet a lot of evidence about the effect of fish.

    Diane Fennell
    Web Editor

  • caroline riley

    As a Type 2 Diabetic, with CKD, I take part in kidney research studies and had heard that eating meat the night before prior to a screening would probably put me into the moderate or severe range (for my kidney disease evaulation) and not eating meat the night before and drinking lots of water and eating a more vegetarian meal,would probably put me more in the upper moderate range. Reading this article puts that info into perspective.

    Is a vegetarian type meal better to go with for kidney disease?

  • Norma Smith

    Was on metformine twice a day until my new endocrinologist took me off of it and put me on humalog fifteen minutes before dinner and lantax before I go to bed. His reason…what I was taking would hurt my kidneys. If you can, please explain this to me. He offered only the concept of use insulin now. Thanks

  • Tom Mims

    I have often considered removing meat from my diet altogether. I will consider eating a meal with cooked meat once a week, instead of once or
    twice a day.

  • Lee Ann

    ….and what about cheese and other dairy products?

  • DW

    I had a blood test last Thursday which showed (electronically available to patients) eGFR at 58, creatinine at 90, with a warning indicating a mild to moderate loss of kidney function. I was shocked as I am a healthy woman in her sixties (e.g. no diabetes, high blood pressure, obesity). I had had a salmon salad sandwich before the test. I decided I wanted to be retested, fasting. The doctor told me it wouldn’t make a difference and to stay off of “Dr. Google.” I fasted and sipped water before the test. The technician, noticing the earlier needle mark, also remarked that it wouldn’t make a difference. The revised test showed eGFR at 68 & creatinine at 78, moving me out of the moderate level of kidney disease.!!? I’m also going to start substituting my second cup of coffee for hot water and lemon to maintain my kidney function.