Overeating in pregnancy could lead to child obesity
Pregnant mothers-to-be who "eat for two" by increasing their intake of fatty and sugary food could unwittingly be putting their children at risk of obesity, according to new research.
Unborn babies and developing infants can have their eating habits programmed by their mothers' food choices, according to the findings.
Children exposed to "maternal junk food" in the womb or early in life may find it harder to resist an unhealthy diet as they grow older, say the researchers.
Dr Stephanie Bayol, from the Royal Veterinary College in London, said: "Our study has shown that eating large quantities of junk food when pregnant and breastfeeding could impair the normal control of appetite and promote an exacerbated taste for junk food in offspring.
"This could send offspring on the road to obesity and make the task of teaching healthy eating habits in children even more challenging."
Controlling appetite involves hormones which act on the brain to regulate energy balance, hunger and satiety - the sensation of "feeling full".
However, feeding is not merely mechanical. It is partly governed by "reward centres" in the brain whose pleasure responses may override normal "feeling full" signals. Previous research has shown that junk foods rich in fat and sugar inhibit satiety while promoting hunger and stimulating the mind's reward centres.
The new research, carried out on rats, indicates that even before birth, exposure to junk food may induce an unhealthy taste for fatty, sugary treats.
Dr Bayol's team studied 42 pregnant and lactating female rats as well as 216 offspring from weaning to 10 weeks of age. Offspring of females, fed junk food while they were pregnant, or when they were lactating, showed a marked preference for foods rich in sugar and fat compared with those whose mothers were given a normal diet. They also ate more.
Writing in the British Journal of Nutrition, the scientists said the same kind of trends could be expected in humans. Dr Bayol said: "Exposure to a maternal junk food diet during their foetal and suckling life might help explain why some individuals might find it harder than others to control their junk food intake even when given access to healthier foods later on in life."
Dr Bayol's co-author, Professor Neil Stickland, who heads the research group at the Royal Veterinary College, said that mothers should be made more aware of risks associated with poor diet.
"The Government is trying to encourage healthier eating habits in schools, but our research shows that healthy eating habits need to start during the foetal and suckling life of an individual," he said.