What’s going on inside your kidneys
Your kidneys don’t just make urine, they remove extra acid from your body and keep things balanced by using natural helpers called buffers. Buffers work like baking soda in your fridge. They soak up extra acid so things don’t get too sour inside your body.
Acid neutralizers are your kidneys’ built-in tools that keep acid in check. When there aren’t enough of them, urine becomes more acidic — and that’s when uric acid stones form (and calcium oxalate stones, too).
With diabetes and insulin resistance, the kidneys cannot make or use enough of these natural neutralizers. That means more acid stays in the urine, lowering its pH. Acidic urine is the ideal environment for uric acid to form crystals.
This is why people with diabetes form uric acid stones more often than people without diabetes. Even when stones are mixed or calcium-based, that chronic low pH still pushes the chemistry toward stone formation.
How diabetes shifts kidney chemistry toward stones
Lower urine pH
Insulin resistance means fewer natural neutralizers. More acid stays in urine, lowering pH and making uric acid less soluble.
More uric acid in urine
High blood sugar and metabolic changes increase uric acid production. Put that into acidic urine, and crystals form quickly.
Less citrate
Citrate keeps crystals from sticking together. Diabetes can lower urine citrate, which removes this natural protection.
Dehydration hits harder
High blood sugar can make you urinate more and lose fluid. Less hydration leads to more concentrated urine, which forms crystals faster.
Weight adds fuel
Extra weight often leads to greater inflammation and insulin resistance. Both make urine more acidic. More acid means more risk.
Higher urinary calcium
When someone has diabetes or insulin resistance, the body lives in a state of higher acid load and higher inflammation. Those two stressors make it harder for the kidneys to retain calcium the way they normally do. Instead of sending most of the calcium
back into the bloodstream (to be used for bones and muscles), the kidneys let more of it slip into the urine.
Here is a simple wrap-up:
- – More acid in the body.
– Diabetes makes urine more acidic.
– The kidneys try to get rid of that extra acid. - – To balance that acid, the body reaches for calcium.
– Calcium helps neutralize acid inside the body.
– As the body uses more calcium to handle acid, more calcium circulates in the bloodstream. - – Extra calcium passes through the kidneys.
– The kidneys filter blood continuously throughout the day.
– When there’s more calcium floating around, more shows up in the kidney filters. - – Inflammation and insulin resistance make it harder for the kidneys to recycle calcium.
– Under normal conditions, your kidneys filter calcium from the blood, then reabsorb most of it before it is excreted in urine.
– This “recycling” step keeps calcium available for bones and muscles.
– But with diabetes, inflammation and insulin resistance interfere with that process. The kidneys cannot reclaim calcium as well as they used to, so more of it slips through and gets lost in urine instead of being reused.
More calcium in urine = a higher chance of calcium-based stones unless sodium and acid load are controlled. That is how the Kidney Stone Diet® Goals can help.
What this means for kidney stone prevention (and why you do not need two different diets)
The Kidney Stone Diet® and a diabetes-friendly plan line up well.
Water
Drink enough to keep your urine pale. Hydration supports blood sugar stability and keeps urine dilute. https://kidneystonediet.com/top-prevention-goal/
Lower added sugar
Lower sugar levels steady glucose levels, reduce inflammation, and support weight control. All of these help kidney chemistry. https://kidneystonediet.com/tips-and-tricks-for-lowering-sugar/
Moderate meat protein
Protein is important, but very large meat portions make urine more acidic. Moderate portions help regulate blood sugar and kidney function simultaneously.
Calcium from food, not pills
Calcium binds to oxalate in the gut, so less oxalate reaches the kidneys. Many diabetics cut dairy to save calories and end up raising urine oxalate instead. You can use plant milks too (but not almonds or cashews). https://kidneystonediet.com/calcium/
Oxalate
Many diabetics were told to lean on spinach, almonds, and almond milk. These foods are nutritious but very high in oxalate, and eating them daily raises the risk of calcium oxalate stones.
You do not need to avoid all vegetables and nuts. You simply need to stop eating the highest-oxalate foods every day and ensure you meet your daily calcium needs. As I said before, many diabetics I speak to were munching on almonds all day long.
Easy swaps for spinach and almonds:
Romaine, arugula, kale, and bok choy instead of spinach. Pistachios, pecans, walnuts, instead of almonds and cashews (portion not perfection applies).
Occasional high-oxalate foods can be managed by eating them with a calcium source, so oxalate is bound in the gut rather than traveling to the kidneys. You can find a chart of the highest-oxalate foods here.
Less sodium
Too much salt increases urinary calcium excretion and raises blood pressure. Lower sodium protects the kidneys and bones. https://kidneystonediet.com/100-tips-for-lowering-sodium/
Fiber
Fiber helps slow digestion, steady blood sugar, and support weight control. It also provides natural alkali, which helps maintain a balanced urine pH. There are plenty of lower-oxalate plant foods to add to your grocery list.
Movement
A short walk after meals improves insulin sensitivity and helps with weight. Better glucose control supports better kidney chemistry. Losing weight will, of course, lower your risk of kidney stones. Whether you have diabetes or not, movement always matters for your health!
Carbs
There are no carb restrictions for the Kidney Stone Diet®, but diabetics DO have to pay attention to carbs. Each diabetic will receive different guidance on their carb count based on activity level, body size, insulin use, etc. Read this from the American Diabetes Association.
What you can actually eat
Plenty.
You do not need two different diets. Count carbs as instructed by your diabetic protocol, and simply avoid the highest-oxalate foods (and make sure you follow the rest of the KSD goals found here).
Your friend,
Nurse Jill
References
Insulin resistance lowers urine pH and raises uric acid stone risk:
https://pmc.ncbi.nlm.nih.gov/articles/PMC1471772/
Diabetes linked to lower urine pH and more uric acid stones:
https://ijlbpr.com/uploadfiles/167vol14issue4pp992-996.20250424073920.pdf
Metabolic syndrome traits increase stone risk:
https://pmc.ncbi.nlm.nih.gov/articles/PMC4633655/
Greater diabetes severity predicts more stones:
Added sugar intake increases kidney stone risk:
Obesity increases kidney stone risk:
Leave a Reply