The Directorate General of Civil Aviation (DGCA) issued the guidelines last week to Indian airlines flying domestically and overseas, setting out body mass index (BMI) and other health requirements for flight attendants.
Cabin crew members could be declared unfit and suspended from flying if their BMI, a measure of weight relative to mass and height, was outside a range considered normal, the regulator said on its website.
The regulator said the rules were aimed at passenger safety, with only fit and healthy cabin crew able to properly discharge duties especially during in-flight emergencies.
The new rules were likely to impact at least 600 members mostly working for state-run Air India, according to the airline's cabin crew union.
"The guidelines are arbitrary and discriminatory. They just can't wake up one fine morning and make some crazy rules citing flimsy reasons," a senior official of the All India Cabin Crew Association said.
"Air India's cabin crew has had a perfect safety record with the way we have been all along. Do they mean to say that all emergencies till now were handled by unfit crew?" the official told news agency AFP citing anonymity.
The guidelines suggest frequent medical checks for cabin crew and based on the resulting reports, they can be categorised as fit, temporarily unfit or permanently unfit to fly.
A BMI between 18 and 25 is stated as normal for males and 25 to 29.9 is overweight, while anything above 30 is obese. For women, a normal BMI falls between 18 and 22, while 22 to 27 is considered overweight and above 27 obese.
A DGCA spokesperson was not available for comment, but the regulator's website recommends exercise and a healthy lifestyle to meet the guidelines.
"Drastic weight reduction plans, medication and surgery for weight reduction have drawbacks which may affect the cabin crew adversely and are to be avoided," it said.
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