This study analyzed the effects of functional cereals processed and produced from yellow corn, soybean, acha, orange peels and moringa leaves' polyphenolic content, glycemic index, starch composition and their effects on α‐amylase and α‐glucosidase enzymes in vitro. Functional cereals were produced as ready‐to‐eat cereals at different proportion with variations in the amount of measured acha flour, soybean flour, and blends of orange peels and moringa leaves while maintaining a constant amount of yellow corn. The produced orange peels and moringa leaves blends inclusion to functional cereals had significantly increased phenolic constituents, showed inhibitory activity on α‐amylase and α‐glucosidase enzymes in‐vitro and reduced glycemic index, starch content and starch to sugar ratios. Interestingly, amongst the produced functional cereals, the best two cereals were with their composition made up of corn, acha, soybean, orange peel, moringa leaves (30: 5:15: 0.5: 0.5) and corn, acha, soybean, moringa leaves (30: 5: 15: 1) which both had the high inhibitory effects on the activities of α‐amylase and α‐glucosidase while depleting starch content in‐vitro when compared with commercially consumed cereals (golden morn). Practical applications Ready‐to‐eat cereals are highly consumed by children and by adults inclusively. Commercial breakfast cereals are readily available and consumed irrespective of the fact it has high calorie constituent as more emphasis is placed on their nutrients value which includes vitamins A, vitamin C and calcium for boosting immune system and for proper body growth and functioning. However, these commercial breakfast cereals (golden morn) owing to the high maize and millet content present in them are unfavorable to certain consumers or individuals with health challenges such as diabetic patients. This study shows that functional cereals produced in‐vitro extensively are not only nutritious but also medicinal in nature, offering benefits in the management of diabetes and related complications.