Wales News online has some good advice here
These meals - takeaways and ready meals - tend to be low in essential nutrients like vitamins, and they also contain a high proportion of salt/sodium, and salt is particularly bad for small children, as well as giving them a taste for salty food which will continue to impair their health as they grow older. They will have higher blood pressure than if they were eating less salty food,. They will be more likely to develop type 2 diabetes and heart problems. They will even be more likely to have a stroke at a young age! - You may also be surprised to learn that it is salt and salty food that causes obesity in children.
You will give your children a healthier and happier start in life if you give them less salty food to eat and if you encourage them to eat plenty of fruit and fresh vegetables.
See Children and Obesity
And see Sodium in foods