Supermarket home brand foods, long derided as cheap and inferior, contain "consistently and substantially" less salt than pricier, branded rivals, new research shows.

A study of 15,680 products from the shelves of Woolworths, Coles, Aldi and IGA found home brand foods have 17 per cent less salt than their branded counterparts.

When sizes differ, it can be hard to work out the best deals Credit:Louie Douvis

The researchers from George Institute for Global Health were surprised to find salt content was an average 27 per cent lower in desserts, 24 per cent in biscuits, 22 per cent in processed meats, and 7 per cent in breads.

But the breakfast cereal category bucked the trend. Salt content in private label cereals was 37 per cent higher.