You can use the remove_menu_page() to hide the particular page. And wp_get_current_user() function will returns the currently logged in user.
See the codes below to hide the menus for john.
add_action( 'admin_menu', 'wp0798_remove_menus' );
function wp0798_remove_menus() {
$current_user = wp_get_current_user();
if( $current_user->user_login == "john" ) {
remove_menu_page( 'edit-comments.php' );
remove_menu_page( 'themes.php' );
remove_menu_page( 'plugins.php' );
}
}