Is it Illegal for An Airline to Fire A Female Flight Attendant For Gaining Weight But Not A Male Flight Attendant?

I am a female flight attendant. I gained 7 pounds over the winter and was asked not to come back to work until I had lost all 7 pounds. My employer said it negatively impacted my interaction with my customers. My male colleague that flies the same route as me gained 10 pounds and can barely fit down the aisle and is still working. Have I been the victim of sexual discrimination?

By Deskin Law Firm
The law states that discrimination may have occurred when an airline's policies impose strict weight restrictions on female flight attendants, but no similar restriction on male employees who performed the same or similar functions because it imposed an "undue burden" on the female flight attendants.

Do I Have to Tolerate Discrimination Based on my Gender?