Malnutrition is a major cause of stunted growth in children, but new research on mothers and children in Egypt suggests that the problem is not just about quantity of food but also quality.

Obesity and malnutrition are often thought of as problems at opposite ends of the nutrition spectrum, but researchers from the University College London found that that 6.7 percent of Egyptian mothers were obese and had stunted children. In these "double-burden" households with obese mothers and stunted children, malnutrition is unlikely to be down to scarcity of food.

"Malnutrition is not only a question of not having enough food, it is also about not having good enough food," Dr. Amina Aitsi-Selmi, lead author of the study, said in a statement. "A household diet rich in energy-dense, sugary food and poor in fruit and vegetables is unlikely to provide all the nutrients that children need to grow. I would consider a child fed on nothing but sugary snacks malnourished, even if they are not under-nourished."

For the study, researchers collected and analyzed data, including weight and height, from more than 25,000 mothers and their children.

The study found that children who were fed chocolate, biscuits or sweets were 51 percent more likely to belong to a double-burden household, whereas children who were fed fruit and vegetables were 24 percent less likely to be in this category

Obesity is traditionally seen as a problem for rich countries and child stunting a problem for poor countries. However, the sudden availability of cheap, high energy-density foods in middle-income countries such as Egypt has led to high obesity rates.

"Policies should not focus on either reducing the calories consumed by mothers or making sure children get enough calories. Improving the diversity and nutrient contents of the whole household diet could help to address both maternal obesity and child stunting, whereas treating them as separate problems may make things worse," Aitsi-Selmi added.

The study also found that maternal obesity in Egypt rose from 22 percent in 1992/95 to 32.3 percent in 2005/08. While stunting levels among children declined from 22.4 to 14.7 percent over the same period, the number of obese mothers with stunted children increased from 4.1 to 5.6 percent.

The findings are detailed in the Maternal and Child Health Journal.