Not that the mother would ever know: the manufacturers are not legally required to disclose the micronutrient levels of the food in the jar.
Researchers from the University of Greenwich School of Science analysed eight different sample jars produced by four of the bigger manufacturers, made up of four meat and four vegetable varieties.
Even when the meals were 'topped up' with 600ml of formula milk, the infant was not getting enough calcium, magnesium, copper and selenium. On average, the levels were 20 per cent below the recommended daily intake for an infant.
The researchers are calling on manufacturers to improve the quality of food we give our babies - and on governments to tighten controls on the food information given to the public.
(Source: Food Chemistry, 2011; 128: 123-8).