Try it an see if he/she eats it. Usually, if they don't like the food, they spit it out. Bettas are fairly particular with food...

As for the nutritional benefits, the vast majority of foods are fine for fish. They are all formulated with vitamins, proteins, and minerals, which are what they need to live healthy lives.

That being said, again, bettas are picky eaters, and generally speaking the cheaper foods are generally less appetizing, and more utilitarian in nature. Try your food out though and see what happens. If he/she doesn't like it, you can try some tried and true foods that most people on here like... Betta Buffet by Omega One, and New Life Spectrum betta formula.

 

I like the Betta Buffet pellets because they have a more protein rich ingredient list.

 

This is the brand of pellets I was using when I first got Murray. (He was an impromptu gift from a co-worker and one day when I came back from lunch, there he was in his little cup with a container of this food sitting next to him.) He had been eating that food (along with the occasional freeze-dried bloodworm and then more recently frozen bloodworms and frozen brine shrimp) until the folks here prompted me to read the label and I realized, as you have, that it isn't the healthiest food out there - it has lots of fillers. So now he is eating Omega One Betta Buffet pellets while my three Bettas who live at home are eating New Life Spectrum. These are the two most often recommended brands and the reason I chose one for Murray (office Betta) and one for my three at home Bettas is because the Omega One pellets are larger and Murray is a bigger boy, while the NLS are very tiny and were better for my girls and my younger Betta who was not much more than a fry when I got him (he was like a little tadpole). All four seem to be thriving on this food, (they all also get frozen blood worms and frozen brine shrimp, and I ditched the dehydrated blood worms having heard they can contribute to dropsy), so I'm happy! I also couldn't swear to it but I feel like Murray's blue is even more intense since I switched pellet brands.

 

Thank you for your quick answer. He is an adult male, and he's been on a staple of Hikari and Aqueon pellets. I ran out of Hikari so he has been eating Aqueon alone for a month or so. I just tried to give him the Wardley food, and he loved it and ate all 5 pellets that I offered to him. Thanks again. My icon is a photo of him if you wanna see him.

 

I'd be worried about the expiration date, because vitamins will degrade over time. Because of its age, that food won't have the full spectrum of vitamins it should.