BABY foods made by firms including Cow and Gate, Heinz and Ella's Kitchen have far less nutrients than homemade meals, according to a new study.
Many contain high levels of sugar and some are promoted for use from four months of age – a time when babies should still be on a diet of breast or formula milk.
Babies would need to eat twice as much shop-bought food to get the same energy and protein as meals cooked at home, researchers found.
It found that many of the weaning foods would not serve their purpose of giving a baby extra nutrients or a range of tastes.
Current guidelines encourage weaning from six months of age, with babies fed only breast or formula milk before this time.
But some parents choose to wean early and baby foods are often marked as "suitable from four months".
The study, from the Department of Human Nutrition at the University of Glasgow, analysed all the baby foods produced by the main UK manufacturers – many available on Irish supermarket shelves. These were Cow and Gate, Heinz, Boots, Hipp Organic, Ella's Kitchen and Organix.
Chef Neven Maguire, a father of twins, said he would always advise parents to cook batches of home-made food and freeze it for young children.
The award-winning chef, along with his wife, Amelda, have backed the first 1,000 days initiative with Danone Baby Nutrition and issued a special recipe book to assist parents.
The products analysed for the study included ready-made soft foods as well as dry foods such as cereal that could be made up with milk or water, biscuits, rusks, bars, snacks and cakes.
Nutritional information for each product – such as calories, fat, iron and calcium - were collected from manufacturers' websites, the products themselves and from email enquiries.
Of the 479 items, 364 or 79pc were ready-made spoonable foods and 201 or 44pc were aimed at infants from four months.
The researchers said the typical calorie content of the spoonable foods was 282 kJ per 100g, almost identical to breast milk at 283 kJ per 100g of formula.
But purees and spoonable foods made at home were "more nutrient dense" than the shop-bought foods. And while commercial finger foods contained more calories, they had a "very high" sugar content.
The iron content of most of the foods was also lower than that found in formula.
A statement from Heinz said: "Generations of parents have trusted Heinz baby foods as safe and nourishing and which are specially prepared to meet babies nutritional needs with recipes that provide the right tastes and textures."
A statement from Organix said it did not add vitamins and minerals to foods due to organic production rules, only in the case of those required by law such as Thiamin or Vitamin B1.
Nobody was available for comment from Hipp Organic.
Helen Messenger, a spokeswoman for Cow and Gate, said: "Our foods offer good quality nutrition tailored to meet babies' needs and must comply with strict legal standards.
"We recommend that our baby foods are used as part of a mixed diet."