For the next three years researchers will be looking at what is on the plates of poor South Africans. What they learn will help improve the national diet.

Over the last two decades what the poor eat has been a bit unclear, but researchers from five universities will try to rectify this.

They are part of the Centre of Excellence in Food Security and their research will investigate recommended serving sizes to meet nutritional needs.

What studies have shown is that poor people on average spend 35% of their income on food and most of this, said project leader professor Hettie Schonfeldt, is spent on staple foods like maize meal and bread.

For most a healthy diet is not affordable.

According to the Labour Research Service, the lowest wages are in the domestic sector, where workers earn R1631 a month.

Schonfeldt said that a family of four would need an income of R3100 to eat healthily.

The Pietermaritzburg Agency for Community, an NGO, has found that the poor are having to borrow more to survive .

A balanced nutritional diet, according to Schonfeldt, would include all food groups. Cheap protein could come from eggs or sardines.

She said a person needed 90g of protein a day.

"What we do know is that lower-income groups are more traditional in their food choices," said Schonfeldt. The poor Indian community preferred rice and spicy food.

The project leader said that o ver the years there had been glimpses into what the poor ate. A survey of consumption last year found that more and more Gautengers were eating sardines.

Schonfeldt believes the reason for this is that adults have been introduced to tinned sardines through their children, who are served the protein in school feeding programmes.

"The research will help to inform government policy and help people make better food choices," she said.

What might emerge, she added, was that the government might fortify staple foods other than maize meal by adding vitamins.