Using foreach change the position of my product collection

Question

The best way to explain this issue is showing an example:

In the product list.phtml I had the following

<?php
     $logger->info($_productCollection->getData());
     foreach ($_productCollection as $_product){
         $logger->info('id product ' . $_product->getEntityId());
     }
     foreach ($_productCollection->getData() as $_product){
         $logger->info('id product with array ' . $_product['entity_id']);
     }
?>

My collection has the next data

array (
  0 => 
  array (
    'entity_id' => '172',
    'sku' => '139373',
    'cat_index_position' => '0'
  ),
  1 => 
  array (
    'entity_id' => '147',
    'sku' => '144486',
    'cat_index_position' => '5'
  ),
  2 => 
  array (
    'entity_id' => '148',
    'sku' => '144485',
    'cat_index_position' => '6',
  )
)

The first foreach I get the next log

id product 147
id product 148
id product 172

In the second foreach:

id product with array 172
id product with array 147
id product with array 148

The first foreach is changing the position of my collection regarding the 'entity_id'. The second foreach is the order that I want but I need the $_product object and not the array.

Why my collection is changing the order of my products?