Is Lentils Safe for Kidney Stones? (Safe)
mg oxalate
per serving
Serving: 1/2 cup (100 g)
Verdict: 🟢 Safe
Per 100g: 8 mg
Data: Harvard T.H. Chan SPH (2024)
The bottom line for Lentils: Safe (🟢), with 8 mg oxalate per serving — comfortably below the 25 mg safe cutoff. There's no need to limit it. Just keep your usual kidney stone basics in place: water throughout the day and calcium-rich foods at meals.
Putting Lentils in context: it lands well below the category average of 20 mg. In the database, 73% of legumes (44 of 60) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical legumes here averages 20 mg oxalate per serving, so Lentils runs 59% below that baseline. That places it among the lower-oxalate options in its category. Why this matters: the gap between two Safe foods can be wide — one may hold 5 mg oxalate while another sits at 24 mg. The lower one leaves more room in your day. See all legumes rated Safe for a full side-by-side.
Why does the safe threshold matter?
The 25 mg line is the reference point clinicians use to separate everyday foods from ones that need caution. Every value on this page traces back to Harvard's 2024 lab analysis, so the threshold is applied to measured data rather than estimates. For context, Lentils measures 8 mg per 1/2 cup, rated Safe.
Can I eat this food every day?
Daily eating is fine for Safe foods (under 25 mg/serving). For Caution or Avoid foods, spread them out and alternate with low-oxalate picks. The idea is keeping your weekly oxalate load manageable, not eliminating any single food. For Lentils, the measured oxalate value is 8 mg per 1/2 cup (Safe).
Where does the oxalate data come from?
The numbers come from Harvard T.H. Chan SPH's 2024 laboratory measurements, published through the OHF database. Direct lab analysis, which is why they're treated as the reference values for food oxalate. For context, Lentils measures 8 mg per 1/2 cup, rated Safe.
Should I also check sodium and calcium?
Definitely. Oxalate is only part of the story — high sodium raises calcium in urine, and dietary calcium (from food, not pills) binds oxalate in the gut. The food's main page lists both, so it's worth checking before you plan around it. For context, Lentils measures 8 mg per 1/2 cup, rated Safe.