Diabetes Mellitus is an alarming disease in the present day since there is no remedy for the same. All it can be done is to seek for prevention and arrest of the illness. Polyphenols are known to act as preventor of the disease. The objective of the investigation done here is to examine how the dietary phenolic acids and flavonoids could help in this goal. A vegetarian diet proposed earlier indicates that it can successfully prevent diabetes if taken regularly. Antidiabetic polyphenols have been estimated from the diet concerned by evaluating their presence in each element of the diet and the result is obtained by adding them up. The total amount of antidiabetic polyphenols is found to be approximately equal to the daily intake amount. So the diet can be thought to be an antidiabetic one and it can prevent diabetes.