It seems you are what your mother ate. If you want a girl, diet - and stay off the breakfast cereal.

The first direct evidence that a child's gender is associated with its mother's eating habits has been discovered, experts said today.

The study shows a clear link between higher energy intake around the time of conception and the birth of sons.

Women who ate around 2200 calories a day were 1.5 times more likely to have a boy than those who consumed under 1850 calories.

While young mothers in Glasgow, yesterday generally agreed with the findings, they pointed out that diet- conscious celebrity mother-of-three, Victoria Beckham, has never managed to conceive a longed-for daughter.

But Anne McCulloch, 33, who runs a mother and toddlers group at Destiny Church, in the south side of the city, believed the pattern of her own pregnancies reflected the findings.

Ms McCulloch, who has a son, Luke, four, and daughter Lara, two, said: "As well as always loving my cereal, I became pregnant for the first time shortly after I starting working as a teacher at a school that had a free buffet.

"I was definitely eating higher calorific food then."

Prior to the conception of her daughter, Ms McCulloch kept a careful eye on her diet.

"I'd put on so much weight with Luke, so I consciously cut down. It looks like I fit the theory."

Emma Scarlett, 23, who has a son Gabriel, two, and daughter Juliette, six months, said: "It's an interesting theory, but there are exceptions. Look at the size of Victoria Beckham - yet she's only had boys."

Meanwhile, Jaqueline Burns, 34, whose son Harris is two, said: "While I wasn't aware of any dietary changes at the time, I probably was eating more when I fell pregnant, because it was just over the Christmas period. Maybe there's something to be said for the study."

But Kim Wray, 30, mother of Luke, three, and Poppy, eight months, was sceptical. "I tend to be conscious of eating healthily anyway, and didn't notice any difference in my diet when I fell pregnant both times, so I'll treat the report with caution," she said.

Eating breakfast cereals around conception was also "strongly associated" with producing sons, said researchers, who calculated that those who did so were 1.89 times more likely to have a boy than those who did not.

Diets high in nutrients, including potassium, calcium and vitamins C, E and B12, were linked to male births.

Researchers from Oxford and Exeter universities studied 740 first-time pregnant mothers.

Nutritional data was collected for three time periods: intake before conception; intake at around 16 weeks' gestation and intake between 16 and 28 weeks' gestation.

The results showed a link between food intake and gender around the time of preconception - but not at other times in pregnancy.

The study said: "In 56% of women, the highest third of preconceptional energy intake bore boys, compared with 45% in the lowest third.

"Intakes during pregnancy were not associated with sex, suggesting that the foetus does not manipulate maternal diet."

The researchers said the mechanisms behind the determination of sex in humans are not well understood.

"However, a pathway has been proposed that could explain our associations of foetal sex with energy intake and breakfast cereal consumption around conception," they said.

"In vitro, glucose enhances the growth and development of male conceptuses, while inhibiting that of females.

"Skipping breakfast extends the normal period of nocturnal fasting.It depresses circulating glucose levels and may be interpreted by the body as indicative of poor environmental conditions."

The researchers said changes in diet could explain why, over the past 40 years, there has been a small "but highly consistent" decline in the proportion of boys born in industrialised countries.

The report's lead author, Dr Fiona Mathews, from Exeter University, said: "This research may help to explain why, in developed countries, where many young women choose to have low-calorie diets, the proportion of boys born is falling."

According to Dr Mathews, the report - published in the journal Proceedings of the Royal Society B: Biological Sciences - could also add to recent debates about whether to regulate "gender" clinics that allow parents to select the sex of their offspring.

"Here we have evidence of a natural' mechanism that means women appear to be already controlling the sex of their offspring by their diet," added Dr Mathews.