Researchers studied over 116,000 Americans to understand how eating patterns affect kidney health. They found that people who eat within a shorter time window each day, skip breakfast, or eat fewer meals may have a higher risk of kidney disease, urinary incontinence, and kidney stones. The study suggests that when you eat—not just what you eat—could be important for keeping your kidneys healthy. This is especially important for people considering fasting diets or restrictive eating patterns.

The Quick Take

  • What they studied: How the timing and pattern of meals throughout the day relates to kidney disease, urinary incontinence, and kidney stones
  • Who participated: Over 116,000 Americans of various ages and backgrounds who participated in national health surveys between 1999 and 2020
  • Key finding: People who compressed their eating into a shorter time window each day had about 10-13% higher odds of developing kidney problems compared to those with longer eating windows. Skipping breakfast and eating fewer meals also showed increased risks.
  • What it means for you: If you’re considering fasting diets or eating in a very narrow time window, you should talk to your doctor first—especially if you have kidney problems or family history of kidney disease. Regular meal timing may be better for kidney health than restrictive eating patterns.

The Research Details

This was a cross-sectional study, which means researchers looked at a large group of people at one point in time and compared their eating patterns to their health conditions. They used data from the National Health and Nutrition Examination Survey, a long-running government health study that tracks Americans’ health and eating habits. The researchers collected information about when people ate, how many meals they had per day, and whether they skipped breakfast. They then looked at medical records to see who had kidney disease, urinary incontinence, or kidney stones.

The researchers used statistical tools to analyze the data and determine if there were real connections between eating patterns and kidney problems. They also tested their findings multiple ways to make sure the results were reliable and not due to chance.

Understanding when we eat is just as important as understanding what we eat. Our bodies have natural rhythms that affect digestion and kidney function. By studying real people’s eating patterns and health outcomes, researchers can identify which timing patterns might be risky. This helps doctors give better advice about fasting diets and meal timing, especially for people with kidney concerns.

This study used a very large, diverse group of Americans (over 116,000 people), which makes the findings more reliable. The data came from an official government health survey, so it was carefully collected and verified. However, because this is a cross-sectional study, it shows associations (connections) rather than proving that eating patterns directly cause kidney problems. The researchers couldn’t control for all possible factors that might affect kidney health.

What the Results Show

The study found three main eating patterns linked to kidney problems. First, people who ate within a shorter time window—meaning they compressed all their meals into fewer hours each day—had about 10% higher odds of chronic kidney disease, 11% higher odds of urinary incontinence, and 13% higher odds of kidney stones compared to people with longer eating windows.

Second, eating fewer meals per day was associated with problems. People who ate only twice a day had about 10% higher odds of urinary incontinence compared to those eating more frequently.

Third, skipping breakfast was particularly risky. People who skipped breakfast had 10% higher odds of chronic kidney disease and 12% higher odds of urinary incontinence. These findings held true even after researchers adjusted for other factors like age, weight, and overall diet quality.

The relationships between eating patterns and kidney problems appeared to be consistent across different groups of people, suggesting these patterns may apply broadly. The researchers tested their findings multiple ways and got similar results each time, which increases confidence in the findings. The effects were strongest for kidney stones and urinary incontinence.

This research adds to growing evidence that meal timing affects health beyond just weight management. Previous studies have shown that eating patterns influence metabolism and inflammation, which could affect kidney function. This study is one of the first to look specifically at meal timing and kidney disease in such a large, representative population.

This study shows associations but cannot prove that eating patterns directly cause kidney problems—other unmeasured factors could be involved. The data was collected at one point in time, so we don’t know if people’s eating patterns changed over time. The study relied on people remembering their eating habits, which can be inaccurate. Additionally, people with existing kidney problems might have already changed their eating patterns, making it unclear what came first.

The Bottom Line

Based on this research, consider spreading your meals throughout the day rather than compressing them into a short window. Don’t skip breakfast, and aim for regular meal frequency (3+ meals daily). These recommendations have moderate confidence based on this study. If you’re considering fasting diets or intermittent fasting, discuss it with your doctor first, especially if you have kidney disease risk factors.

This is particularly important for people with family history of kidney disease, those with diabetes, people over 60, and anyone considering fasting diets. People with existing kidney problems should definitely talk to their doctor before changing meal timing. Healthy young adults with no kidney risk factors may have more flexibility, but regular meal timing is still likely beneficial.

Kidney health changes happen gradually over months and years. You won’t see immediate results from changing meal timing, but consistent patterns over 3-6 months may help reduce kidney disease risk. If you have urinary incontinence, some people report improvements within weeks of more regular eating patterns.

Want to Apply This Research?

  • Log your eating window daily (e.g., ‘ate between 7am-7pm’ = 12-hour window). Track the number of meals per day and whether breakfast was eaten. Monitor this for 4 weeks to establish baseline, then work to extend eating window and maintain consistent meal frequency.
  • Set phone reminders for breakfast, lunch, and dinner at consistent times. Use the app to plan meals across the day rather than clustering them. If using intermittent fasting, gradually extend your eating window from 8 hours to 10-12 hours while monitoring any symptoms.
  • Weekly check-ins on meal consistency and eating window length. Monthly review of patterns to ensure you’re maintaining 3+ meals spread throughout the day. If you have kidney concerns, share monthly reports with your healthcare provider to track any changes in symptoms or lab values.

This research shows associations between eating patterns and kidney health but does not prove cause-and-effect relationships. This information is for educational purposes only and should not replace professional medical advice. If you have kidney disease, diabetes, or are considering significant changes to your eating patterns, consult your doctor or registered dietitian before making changes. People with existing kidney conditions should work with their healthcare team before adopting fasting regimens or restrictive eating patterns. This study cannot determine individual risk—your personal risk depends on many factors including genetics, overall diet, hydration, and medical history.