Different studies defined 'leafy greens' differently—some included spinach, others Chinese greens—so it's hard to know exactly what foods are linked to lower diabetes risk.
Scientific Claim
Dietary intake of green leafy vegetables was measured inconsistently across studies, with varying definitions (e.g., spinach, kale, Chinese greens) and portion sizes, introducing potential misclassification bias that may affect the precision of the observed association.
Original Statement
“The studies that investigated green leafy vegetables did not all use the same criteria; two papers included spinach, kale, and lettuce, another included Chinese greens, greens, and spinach, and the other paper did not provide a definition.”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
association
Can only show association/correlation
Assessment Explanation
The claim is a neutral description of measurement variability as reported by the authors, without implying causation or overstating the impact. It accurately reflects the study’s own limitations section.
Evidence from Studies
Supporting (1)
Fruit and vegetable intake and incidence of type 2 diabetes mellitus: systematic review and meta-analysis
Even though the scientists found that eating more leafy greens like spinach and kale might lower diabetes risk, they used different ways to measure what counts as 'leafy greens' in each study — which could make the results less precise, just like the claim says.