This study aims to correlate bread staling with starch digestibility rate. The study also investigates the effects of the use of an anti-staling agent (carboxymethyl cellulose (CMC)) on starch digestion and glycemic index value. The results indicate that CMC utilization has an insignificant effect on a specific volume of bread, but, it decreases the crumb and crust lightness. CMC improves the textural properties of bread and reduces hardness during storage. The highest firmness increase is detected in the control sample, and the rate of firmness accelerates after the second day of storage. However, the addition of CMC leads to a decrease in the firmness of the bread. As expected, CMC is effective in slowing bread staling. The most novel results of the study are revealed through starch digestion. That storage period and CMC utilization affect significantly (p < 0.05) starch hydrolysis rate and staling has a decreasing effect on starch digestibility. After 4 days of storage, the expected glycemic index (eGI) decreases in all bread samples, and the highest decrease is observed in 5% CMC-added bread samples. These results are also correlated with an increase in total dietary fiber content after the storage period.