In a study spanning 421 European children across multiple years, researchers asked whether the body itself might serve as an honest witness to what a child eats — and found that it does, in part. Blood metabolites, those small molecular byproducts of digestion, arranged themselves into patterns that mirrored three distinct ways of eating, with omega-3-rich profiles emerging from fish and olive oil diets and inflammatory fatty acid signatures appearing in children consuming poor-quality fats and sugars. The findings are exploratory rather than conclusive, but they point toward a future in which