Kinetic energy of a body of mass $m_1$
$K_{1} = \frac{1}{2}m_{1}v^{2}_{1} = \frac{p^{2}_{1}}{2m_{1}}$
Again, kinetic energy of a body of mass $m_{2}$.
$K_{2} = \frac{1}{2}m_{2}v^{2}_{2} = \frac{p^{2}_{2}}{2m_{2}}$
If $p_{1} = p_{2}$, $\frac{K_{1}}{K_{2}} = \frac{m_{2}}{m_{1}}$
If $m_2 > m_1$
Then, $K_1 > K_2$ i.e. the kinetic energy of light body will be more than the kinetic energy of heavy body when both have same momentum.