Aeroflot is facing a legal battle with several of its female flight attendants who claim it favours slim and attractive cabin crew.
A Moscow court on Tuesday rejected a sex discrimination claim by stewardess Irina Ierusalimskaya.
She plans to appeal, and is backed by a top Russian human rights and trade union official, Boris Kravchenko, according to the BBC.
The Russian carrier argues that every extra kilogram of weight forces Aeroflot to spend more on fuel.
Its application form for would-be flight attendants requires details of height, weight and clothing size.
Staff have to meet a minimum height requirement because they need to store hand luggage in the overhead lockers, Aeroflot says.
The court will soon consider a similar claim from another Aeroflot flight attendant, Yevgenia Magurina.
“A heavy physical build makes it harder for a flight attendant to move around the cabin and provide a smooth service for the passenger,” an Aeroflot official told the court.
The airline said that “cabin crew are the face of any airline. Cabin crew of a national carrier are the calling card of their country. Their deportment and how they serve passengers creates the first impression of and attitude towards Russia”.
In a lengthy rebuttal of the allegations, a statement from the airline said: “Aeroflot does not discriminate based on age, sex, weight, appearance, religious or political convictions, or indeed any other grounds.
“Aeroflot therefore robustly denies these baseless allegations and will vigorously defend itself if any legal proceedings come to court.”
It added: “Aeroflot has exacting requirements for all staff based on the specific demands of their duties, where the priority is the comfort and safety of passengers.
“The principal selection criteria are communication skills, a friendly and approachable nature, knowledge of foreign languages and neat and tidy self-presentation.”