Nutritional diversity is a crucial aspect of dietary quality, impacting health outcomes and disease risk. This study employs graph theory and mathematical modelling to quantitatively assess the nutritional diversity of diets. A sample of 25 individuals' dietary consumption of key nutrients is transformed into a graph representation, with nodes representing nutrients and edges indicating interactions. Graph metrics, including node centrality and network density, are utilized to calculate diversity scores for each individual's diet. The findings reveal varying degrees of nutritional diversity among the sampled diets, with implications for individual and population health. While based on experimental data, this study offers insights into the potential of graph-based approaches to inform dietary recommendations and advance our understanding of dietary quality.