Unfortunately, that shop keeper has no clue about feeding Leopard Geckos. First of all, a Leo under one year old should be given food every day. Many adult Leos are fine with every other day feedings. Secondly, no matter what their age, they should be given as many feeder insects as they will eat in 15-30 minutes. Plus a small dish of mealworms or superworms can be left in the setup to be eaten at their leisure. I think my Leos would starve if they only got 1-2 crickets every other day. Mine all eat on average between 5-8 appropriate sized crickets and about the same number of small/medium superworms every day. Well, my 2 adults are not eating every day right now and are eating less because they are brumating, but they are usually real pigs LOL Every Leo is different and you may find yours eats less than mine or maybe more. It may not eat every day either, but because it is under a year old, do offer food every day 