  Proton momentum distributions of the $^{12}C$, $^{16}O$, $^{40}Ca$, $^{56}Fe$
and $^{208}$Pb nuclei are calculated by a model using the natural orbital
representation and the experimental data for the momentum distribution of the
$^{4}He$ nucleus. The model allows realistic momentum distributions to be
obtained using only hole-state natural orbitals (or mean-field single-particle
wave functions as a good approximation to them). To demonstrate the model two
different sets of wave functions were employed and the predictions were
compared with the available empirical data and other theoretical results.

Nuclear Theory