Baby foods made by firms including Cow and Gate, Heinz and Ella's Kitchen have far fewer 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.
The study, from the department of human nutrition at the University of Glasgow, said many weaning foods "would not serve the intended purpose" of giving a baby extra nutrients or a range of tastes and textures. 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".
Experts analysed all the baby foods produced by the main UK manufacturers. These were Cow and Gate, Heinz, Boots, Hipp Organic, Ella's Kitchen and Organix. Products included ready-made soft foods and dry foods such as cereal that could be made up with milk or water, biscuits, rusks, bars, snacks and cakes.
Of the 479 items, 364 (79%) were ready-made spoonable foods and 201 (44%) were aimed at infants from four months. Some 65% of the products were sweet foods. 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. Examples of homemade foods included chicken stew, beef with mash, stewed apple with custard and apple with rice pudding. 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.
Writing in the journal Archives of Disease in Childhood, the researchers said: "The UK infant food market mainly supplies sweet, soft, spoonable foods targeted from age four months. Most products are ready-made spoonable foods that are no more energy dense than formula milk, and are generally much less nutrient dense than homemade foods. This meant that around 50g of a soft spoonable family food might supply the same amount of energy and protein as 100g of ready-made spoonable food."
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. 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 which includes homemade foods plus breastmilk or formula, which remains the most important source of nutrition for infants under 12 months. The latest Government data shows that most babies in the UK are getting the nutrients they need from their weaning diets and that there are no significant shortfalls."