Just spent $79 damn dollars on premium version and can’t change my user name.

You can change your username one time as follows;

On Website:
Click here to jump to our website using your default browser. If you are on a mobile device, your mobile browser will be used.
Or you can use your computer by logging in at www.myfitnesspal.com, click "My Home" then "Settings,” followed by "Change username."


In our Android and iOS apps:
Go to the "Menu" (or "More" page) > "Settings" > "Edit Profile" (or "Profile") > Tap your username > then confirm you wish to update your username. You will then be directed to a web page where you will be asked to log into your account to finish your request.

If you have already changed your username before, please contact our Customer Happiness team so they can assist you with providing an additional username change. To reach our support team for assistance, please visit https://myfitnesspal.zendesk.com/hc/en-us or email directly to support@myfitnesspal.com