Thanks to modern farming, animals are too fat, and as well as leading to obesity in humans, this is also contributing to a growing incidence of mental ill health, claimed Professor Michael Crawford of the Institute of Brain Chemistry & Human Nutrition at London Metropolitan University.
Modern breeds of cattle have six times the fat content of their wild ancestors, he told an Irish Food Agency conference. "The human genome is pretty ancient, and we're adapted to wild foods, not what we're eating today."
Crawford also repeated earlier claims that the fat content of chicken was more than three times higher than in 1969, up from 17.7g of fat per 100g, compared with 5.7g in 1969. With fewer vital fatty acids, mental health problems were now taking up more government health spending than any other complaint, he added.
But farming leaders condemned the comments as both unscientific and incorrect. "If there is any fat, it'll be cut off at the cost of the farmer and the retailer," said NFU livestock adviser Peter King, "so it is not in farmers' interests to overfeed cattle."
Nutritionists and farmers say beef is actually becoming leaner, because of advances in cattle genetics and husbandry. Carcase fat has fallen from 30% to 25% over the past 30 years, and modern butchery reduces it to just 5%, said nutritionist Mabel Blades. Pig carcases now average 4% fat and lambs 8%, she added.
"He's barking up the wrong tree," said British Poultry Council chief exec Peter Bradnock, adding that chickens were already bred for leanness. "You can't compare the way he's arriving at his results with the established data."
Crawford tested only one chicken for fat content, whereas the government tests a range of different sizes to arrive at an average.
However, the poultry industry still hopes to gather definitive evidence to refute claims. FSA plans to test fat levels have stalled.