Melinda Gates has declared that she and her husband Bill Gates, through their foundation, are set to spend $776 million in tackling hunger over the next six years, doubling existing commitments, in their effort to address the continuing shortage of funds on malnutrition.

"Malnutrition is the underlying cause of nearly half of all under-5 child deaths," Melinda Gates said on Thursday in an announcement in Brussels. "Yet for too long the world has under-invested in nutrition. Today we see an opportunity to change that."

Gates called on leaders of European countries to prioritise the nutrition of women and children, the Huffington Post wrote.

The pledge by the Bill and Melinda Gates Foundation will be matched by a $180-million funding from Britain's Department for International Development. Much of the funds will be spent in countries where there is serious malnutrition such as India, Ethiopia, Nigeria, Bangladesh and Burkina Faso.

In a statement, the foundation said millions of children die annually because they can only access substandard nutrition during their crucial 1,000-day period, from the day they were conceived until they turn two years old.

"Many European donors are now prioritizing nutrition, which we believe will be one of the fundamental solutions to help cut child mortality in half by 2030," Gates said.

The additional funding announced in Brussels will be allocated to help women and girls before they get pregnant in order to improve the likelihood of a healthy mother and child.

"From their leadership as farmers, entrepreneurs and consumers to their role as mothers; investment in women and girls will be key to improving nutrition globally," Gates said.

The extra funding will also be used on measures "proven to improve nutrition" including fortifying food and promoting breastfeeding.

Bill Gates, founder of Microsoft and Melinda Gates' spouse, is the richest person in the world with an estimated net worth of $79.3 billion. Gates has been praised by Oxfam in the past for giving away much of his fortune, calling him "an example to the rest of the world's billionaires"