A south Indian newspaper has offered its readers “scientifically proven” advice on how to conceive a boy, including eating plenty of mutton, never skipping breakfast and always sleeping with your face turned leftwards.

The advice, which ran on Tuesday in the Kerala newspaper Mangalam, highlights the deep-rooted and often deadly preference for male children that persists in Indian culture.

Admitting its methods might not be guaranteed to work, the column suggested that women looking to conceive boys needed to ensure they never missed breakfast, and ate much more than their normal intake throughout the day.

Mutton and dry grapes were the best food for women, while men needed to avoid eating food with high acid content, it said. It also advised readers to attempt procreation on only the first, third, fifth or seventh days of the week, when sperm were “scientifically” shown to be stronger.

The column was translated from Malayalam by the Indian feminist website the Ladies Finger, which “recommended” the advice to its readers, “especially if, God forbid, the blood moon sacrifices conducted by your extended family for a male heir haven’t worked out yet”.

A preference for boys is deeply ingrained in many of India’s cultures, and tens of thousands of girls are thought to be aborted each year. The result is a heavily distorted gender ratio, with India’s most recent census finding there were 940 girls born each year for every 1,000 boys. The disparity is worst in Haryana, a state in the country’s north, where just 830 girls are born for every 1,000 boys.

Ranjana Kumari, a leading activist in the movement against female foeticide, said efforts were under way in five Haryana districts to change community attitudes about the economic potential of women, which she said was the most potent way of dissuading people from aborting female foetuses. “What works best is changing the image of girls in our society. Showing that girls can be educated, employed, take care of their families,” she said.

Kumari said Kerala was one of India’s most progressive and educated states, so it was surprising that they were “tolerating such stupid, unscientific lies” as those published in Mangalam.

The Indian prime minister, Narendra Modi, has been vocal about the need to end the practice, comparing foeticide to Ravana, a demon king from Hindu scripture whose effigy is ceremonially burned each year. In a speech this year to mark the ceremony, he ranked sex-selection alongside terrorism, caste discrimination, religious hatred and corruption as the main “evils” in Indian society.