We've always kept our packaging on the small side in the interest of nutrient preservation. With larger packaging the food is often exposed to the elements over weeks and months, which is very destructive to the food. So many of the micronutrients included in our products are fragile, and must be treated accordingly. We want our painstaking manufacturing efforts to result in superior nutrition reaching the companion animal, not degrading in a "convenient" large open bag. For more information, please see http://www.wysong.net/pet-health-and-nutrition/why-are-nutri-pak-sizes-small.php
One size permits the use of our new packaging technology that affixes a computer generated label to the bag. The resulting flexibility permits formulation changes as new advancements in the rapidly unfolding field of nutrigenomics occur. Additionally, having only one size permits more efficient turnover of products and reduces manufacturing waste.