Researchers followed nearly 100,000 British adults for about 9 years to see how their eating habits affected kidney health. They found that people who followed a “Planetary Health Diet”—which emphasizes vegetables, fruits, and whole grains while limiting sugary drinks and processed foods—had about 26% lower risk of developing kidney disease compared to those who didn’t follow this diet. This eating pattern is good for both your body and the environment, making it a win-win choice for long-term health.

The Quick Take

  • What they studied: Whether eating a diet that’s good for the planet (lots of plants, less processed food) helps prevent kidney disease
  • Who participated: Nearly 98,400 middle-aged and older adults from the UK who didn’t have kidney disease when the study started. Researchers tracked their eating habits and health for about 9 years
  • Key finding: People who most closely followed the Planetary Health Diet had a 26% lower chance of developing kidney disease compared to those who followed it least. During the study, about 2.7% of participants developed kidney disease
  • What it means for you: Eating more vegetables, fruits, and whole grains while cutting back on sugary drinks and processed foods may help protect your kidneys. However, this doesn’t guarantee you won’t get kidney disease—it’s one factor among many that affect kidney health

The Research Details

This was a long-term observation study where researchers followed real people over time rather than randomly assigning them to different diets. Scientists looked at nearly 98,400 British adults who didn’t have kidney disease at the start. They measured what people ate using detailed food diaries (at least two separate 24-hour records of everything eaten) and created a score called the Planetary Health Diet Index that ranges from 0 to 130 points. Higher scores mean the person’s diet was more aligned with eating patterns that are healthy for both people and the planet.

The researchers then tracked these people’s health records from July 2011 to November 2021—about 9 to 10 years. They looked at medical records from doctors’ offices, hospitals, and death certificates to find out who developed kidney disease. They used statistical methods to compare kidney disease rates between people with the highest diet scores and those with the lowest scores, while accounting for other factors that might affect kidney health like age, weight, exercise, and smoking.

This type of study is valuable because it follows real people in their everyday lives rather than testing them in a lab. It shows what actually happens when people eat different ways over many years. The long follow-up period (about 9 years) gives researchers enough time to see if kidney disease develops, which is important because kidney disease often develops slowly without obvious symptoms.

This study has several strengths: it included a very large number of people (nearly 100,000), followed them for many years, and used detailed food records rather than just asking people to remember what they ate. The researchers also adjusted their analysis for many other factors that could affect kidney health. However, the study was done in the UK, so results might be slightly different in other countries with different populations and food availability. Also, people who volunteer for health studies might be more health-conscious than the general population.

What the Results Show

During the 9+ year study, 2,635 people (about 2.7%) developed kidney disease. When comparing people who followed the Planetary Health Diet most closely to those who followed it least, the high-adherence group had a 26% lower risk of developing kidney disease. This means if 100 people in the low-adherence group developed kidney disease, only about 74 people in the high-adherence group would be expected to develop it.

The researchers found that several specific foods were most protective: eating more vegetables, fruits, and whole grains each reduced kidney disease risk. Interestingly, eating fewer starchy vegetables (like potatoes), less poultry, and avoiding sugary drinks and added sugars also helped reduce risk. The benefits held up even when researchers tested different ways of analyzing the data, suggesting the findings are reliable.

The study identified which foods had the biggest protective effects. Vegetables, fruits, and whole grains were the strongest protectors—each additional serving reduced risk slightly. Limiting sugary drinks and added sugars showed the biggest risk reduction among the foods to avoid. The protective effect was consistent across different age groups and didn’t change significantly based on other health factors like weight or exercise level.

Previous research has shown that plant-based diets and diets low in processed foods are good for kidney health. This study adds to that evidence by showing that a specific diet pattern—one designed to be both healthy for people and sustainable for the environment—offers kidney protection. The findings align with other research showing that vegetables, fruits, and whole grains reduce the risk of many chronic diseases.

The study only included people from the UK, so results might differ in other countries. People who participated in this study might be more health-conscious than average, which could affect results. The study shows association (two things happening together) but can’t prove that the diet directly caused the lower kidney disease risk—other unmeasured factors could be involved. Additionally, people’s diets can change over time, but the study only measured diet at the beginning.

The Bottom Line

If you want to protect your kidney health, consider eating more vegetables, fruits, and whole grains while limiting sugary drinks, added sugars, and processed foods. This evidence is moderately strong based on a large, long-term study. However, this should be one part of overall kidney health, which also includes managing blood pressure, staying hydrated, exercising, and regular check-ups with your doctor.

This is relevant for anyone concerned about kidney health, especially middle-aged and older adults. It’s particularly important for people with risk factors for kidney disease like diabetes, high blood pressure, or a family history of kidney problems. If you already have kidney disease, talk to your doctor before making major diet changes, as kidney disease sometimes requires specific dietary restrictions.

Kidney disease develops slowly over years, so you wouldn’t expect to see dramatic changes quickly. However, eating a healthier diet can improve other markers of kidney function (like blood pressure and blood sugar) within weeks to months. The full protective benefit against kidney disease likely takes years to develop.

Want to Apply This Research?

  • Track daily servings of vegetables, fruits, and whole grains, plus monitor sugary drink consumption. Set a goal like 5+ servings of vegetables/fruits daily and 3+ servings of whole grains, while limiting sugary drinks to fewer than 2 per week
  • Use the app to log meals and get real-time feedback on how closely your diet matches the Planetary Health Diet pattern. Set reminders to include vegetables at each meal and swap sugary drinks for water or unsweetened beverages
  • Track your Planetary Health Diet score weekly and monitor related health metrics like blood pressure and weight monthly. If you have kidney disease risk factors, also track any kidney function tests your doctor orders

This research suggests an association between diet and kidney disease risk but does not prove cause and effect. This information is for educational purposes and should not replace professional medical advice. If you have kidney disease, are at risk for kidney disease, or are considering major dietary changes, consult with your doctor or a registered dietitian before making changes. Some people with kidney disease require specific dietary restrictions that differ from general healthy eating guidelines.