Please note that uninstalling the app or closing your account will not automatically stop your subscription - you must cancel the subscription. To do that, you need to cancel the recurring payments. Bear in mind, the subscription you've purchased remains active until it reaches its expiry date even when you cancel it right after the purchase.
For example, if you purchase a 1 month subscription and then choose to cancel it, the subscription will remain active until the end of the 1 month period.Depending on the payment method you've used, there are different ways of cancelling your subscription:
1) iTunes: Your subscription can only be cancelled on your iTunes account by following these instructions: Apple Instructions (English)
NOTE: We can't cancel your iTunes subscription for Healthy Pantry Premium as Apple does not give us access to your payment data. If you don't have the access to your iTunes account, you will have to contact Apple Support. Please make sure to log into the correct iTunes account. If you can't see the cancel button in iTunes that either means you don't have an active auto-renewing subscription (it might already have been cancelled), or you're not logged into the correct iTunes account.