In Indonesia a new law has been passed that stipulates all babies should be exclusively breastfed for the first six months of life. From early next year, anyone who stands in the way of this will be fined up to 100m rupiah (£7,000; $11,000) and sentenced to up to a year in prison.
When you enter the slum of Cilincing in north Jakarta, the first thing that hits you is the stench; a curious mixture of shellfish and rubbish.
Cilincing overlooks the sea. Children play in its dark alleyways as fishermen weave through, selling their wares. People live on top of one another here, in tin shacks stacked up against the walls.
Cilincing is typical of many impoverished areas in Jakarta. There are flies everywhere. Goats and chickens roam freely, and often eat and defecate next to their owners' homes.
All of this adds to the already unsanitary and unhygienic conditions. Aid workers say this area of Jakarta has one of the highest infant mortality rates in the city.
Children here get sick often, which is why US-funded charity group Mercy Corps began teaching mothers about the merits of breastfeeding a few years ago.
Health workers say one of the easiest and most effective ways to build up immunity in young children is to breastfeed them exclusively for the first six months. The programme has now extended to more than 30 slums in the area.
At a monthly seminar, young mums with their babies gather in a cramped room, to learn about the benefits.
Cucu Alowiya, the group's leader, told me how difficult it was initially to convince the women to exclusively breastfeed their children.
"In the beginning they didn't believe me," she said.
"They told me they had seen commercials on TV saying formula milk was better. But I told them breast milk is cheaper and more practical, and better for their children."
The merits of exclusive breast-feeding for six months have been espoused by the World Health Organization and Unicef.
Both these organisations say that if Indonesian children get this kind of care, it could help to address high malnutrition rates in the country.
In a 2007 government survey, almost 40% of the children under five who were surveyed reported stunted growth due to malnutrition.
Almost all Indonesian women traditionally breastfeed their children at some point after birth, but the problem lies in the fact that many don't do it exclusively.
In fact, recent data has shown that exclusive breastfeeding rates in Indonesia have dropped by 10% between 2006 and 2008.
Back to work
But exclusive breastfeeding for most women - especially those who need to go back to work to support their families - is a very real challenge.
Diana, 22, works in a garment factory, and took time off after she gave birth to her son. Indonesia provides women with three months' paid maternity leave.
Diana has seen the merits of breastfeeding her son. When he was first born, she fed him breast milk but then switched to formula milk when she thought about going back to work.
Diana says he became very sick, and lost weight. She switched back to breast milk, and delayed her return to work - but she can't afford to put it off any longer - she needs the money.
"It's very difficult as a working woman to breastfeed my child for six months," she told me as we sat in her house in the slum.
"The factory where I work doesn't have the necessary facilities, and they don't care about us to be honest.
"Some of my friends who have gone back to work have had no choice but to give their children formula milk."
But the Indonesian government says the new law will help young mothers like Diana by enforcing rules that companies must provide female employees with breastfeeding facilities.
"The law will have detailed steps on how companies must provide facilities for nursing mothers to breastfeed as well as to pump and store their breast milk," said Tari Tritarayati of Indonesia's Ministry of Health.
"It will also regulate milk companies, to ensure they don't give incentives to health care workers to push their products."
These are significant steps in a country which has been criticised for not doing enough to protect the rights of working mothers.
Formula milk debate
Indonesia has also yet to adopt the International Code of Marketing of Breast Milk Substitutes, which regulates the milk formula industry by ensuring that its products aren't freely marketed to new and easily influenced mothers.
But while Indonesia's new law has been applauded for being a step in the right direction - some in the medical community feel it doesn't go far enough.
Dr Fransiska Erna Mardiananingsih says the government should focus its efforts on the powerful, multi-million dollar formula milk industry.
A million babies on average are born in Indonesia every year.
"The hands of the formula companies are everywhere," says Dr Mardiananingsih.
"These companies host promotional events... The information is really misleading. Some adverts say their products are very close in composition to breast milk, or have certain additional nutritional content, which makes your babies smarter or healthier, or fatter. This kind of information confuses mothers."
But milk formula companies say that's not true.
Nestle, one of the biggest players in Indonesia's infant food industry, told the BBC: "We strongly disagree with any such accusation that Nestle actively and aggressively promotes our infant formula products in Indonesia.
"Nestle believes that breast milk is best for babies, and we support exclusive breastfeeding for six months from the baby's birth."
The statement goes on to say that Nestle also provides breastfeeding rooms in their offices, and breastfeeding posters to health institutions.
It is a debate that will likely continue as the officials try and figure out how best to implement the new law.
There are still many unanswered questions - how will the law be enforced? What sorts of checks will there be to ensure companies build facilities for working mothers? How realistic is it that milk formula companies will be prosecuted for breaking the new law?
Ensuring that this law is properly implemented is critical.
Malnutrition has been the cause of death of millions of young Indonesian children. The new law is a well-intentioned attempt to address the crisis.
The government needs to ensure it targets those who stand in the way of its efforts for the sake of the next generation.