A new study published in Life Metabolism reports that a single post-meal blood biomarker, 1-hour postprandial SPARC (SPARC-1H), can predict who will benefit most from adopting a Mediterranean diet. The discovery provides one of the clearest examples to date of how precision nutrition can identify individualized dietary responses using a simple blood test rather than complex multi-omics models.

Researchers led by Drs. Jiqiu Wang and Guang Ning at Ruijin Hospital, Shanghai Jiao Tong University conducted a six-month randomized controlled feeding trial involving 235 Chinese adults with overweight or obesity and prediabetes. Participants were assigned to one of three calorie-restricted eating patterns: a Mediterranean diet, a traditional Jiangnan diet, or a control diet reflecting contemporary Shanghai dietary habits (Figure 1). All participants consumed controlled meals five days a week with a 25% caloric deficit.

Across the trial, investigators measured circulating SPARC, a secreted protein linked to adipose inflammation, at fasting, 1 hour, and 2 hours after glucose intake. They found that only the 1-hour post-glucose SPARC level at baseline, not fasting or 2-hour SPARC, predicted the magnitude of metabolic improvement in the Mediterranean diet group. Individuals with lower baseline SPARC-1H experienced greater improvements in insulin resistance, fasting insulin, and fasting glucose after six months of dietary adherence under caloric restriction. This predictive pattern did not appear in the Jiangnan or control diet groups, suggesting a diet-specific metabolic interaction.

Additional analyses showed that SPARC-1H was strongly connected to changes in specific lipidomic profiles, particularly reductions in several plasmalogen species linked to red-meat intake and metabolic inflammation. These lipid shifts were characteristic of the Mediterranean diet and may underlie why SPARC-1H functions as a selective predictor for this dietary pattern.

The study also revealed that different dietary patterns may require different predictive indicators. While SPARC-1H predicted metabolic improvements only in the Mediterranean diet group, fasting SPARC, rather than postprandial SPARC, was associated with improvements among participants following the traditional Jiangnan diet. This demonstrates that biomarkers should be interpreted within specific dietary contexts rather than applied universally.

The findings suggest that a single post-meal biomarker could help identify individuals most likely to achieve significant cardiometabolic benefit from a Mediterranean diet. The work highlights a practical route towards personalized dietary recommendations for people at risk of metabolic diseases and underscores the importance of considering diet-specific physiology when developing precision nutrition tools.
DOI：10.1093/lifemeta/loaf039/8322732.