A comparative study using an analytical correlated wave function for two K-shell active electrons and two electron uncorrelated wave function for two K-shell bare electrons, on information theoretic quantities such as, Rényi entropy, Tsallis entropy and Onicescu information energy are presented for helium, lithium and beryllium. Obtained differences can be interpreted as a measure of electron correlation and quantified for these quantities. Correlated one electron probability density is delocalized with respect to uncorrelated one-electron probability which increases/decreases the correlated values of these quantities. Results for helium atom are in good agreement with the available data in the literature.