Diabetes and obesity are pathological conditions affecting millions of people worldwide. Examination of metabolites and of their relation with other clinical parameters can give valuable information on the pathophysiological changes and eventually can lead to identification of new potential biomarkers allowing for a better patient stratification and prediction of complications. We determined the changes in the levels of amino acids and biogenic amines in obesity and T2D as compared to healthy controls, and we have successfully proved already known and demonstrated some new, previously unknown correlations between the levels of amino acids and clinical laboratory parameters and patients data, respectively. The applied network model also provided useful information about the pathways and protein associations that are characteristic to obesity and/or T2D. We acknowledge the need for further research to validate the emerging concepts and gain a deeper understanding of the complex metabolic dysregulation associated with obesity-induced insulin resistance and T2D. Besides serum, tears was also examined, but due to the high variance in the data and the relatively low sample number available, no statistical significances were established between the studied groups. This points out to one of the main limitations of our study, namely the requirement for more donors to enable a better patient stratification and the utilization of tears for diagnostic purposes. Despite these limitations, our results offer valuable information that can serve as potential targets for mechanistic studies aimed at developing future therapies for insulin resistance in advanced obesity and T2D. In our next study we examined the amino acid and biogenic amine concentrations in various grape-derived beverages. The level of amino acids and biogenic amines in Furmint, Aszú, and Essence wines, as well as wine vinegar from the Tokaj wine region was characteristic to the studied beverage, reflecting their different production process. By comparing Aszú-Furmint wine pairs from the same winery and year, we identified some amino acids and biogenic amines sensitive to the presence of botrytized grapes in Aszú. Our experimental setup can provide a relatively fast and easy-to-implement analytical approach for the quality control and nutraceutical examination of wine and wine vinegar.