One in every five children younger than five is malnourished nationwide and one in six newborns has a low birth weight, one cause of infant deaths, according to a recent study from the Colombo-based Institute of Policy Studies (IPS).
But the situation is worse for children of tea estate workers, with one in three classified as underweight and 40 percent of babies born with too-low weight, IPS noted.
Ramasamy Ramakrishnan, 46, a tea estate worker and father of five, and his wife, who is also a tea harvester, earn US$130 monthly to support a family of seven, including five school-aged children.
"It is difficult. We survive somehow. But I cannot find any other job," he told IRIN.
His family is among the one-and-a-half million people - or some 5 percent of Sri Lanka's 21 million population - who work in the tea sector, according to government estimates.
The most recent national poverty study conducted in 2009-2010 noted that 11.4 percent of these families lived below the national poverty line of 3,028 Sri Lankan rupees per month, or roughly $27.
Income nutrition cycle
Household income plays a major role in determining nutrition levels of under-fives, with those among the country's poorest 20 percent three times more likely to be malnourished as those in the richest quintile, noted IPS.
In the government's most recent demographic and health survey (DHS) conducted in 2006-2007 some 17 percent of under-fives surveyed were stunted - a sign of chronic malnutrition and lack of nutrients.
Nuwera Eliya District - 150km south of the economic capital of Colombo - and the adjoining Badulla District, which both have large tea plantations, recorded the highest stunting rates nationwide that year, 44 and 33 percent respectively.
Angela de Silva, a lecturer at the University of Colombo's Faculty of Medicine and vice-president of the Nutrition Society of Sri Lanka said poverty and poor living conditions created an inter-generational cycle of malnutrition.
"The disadvantaged kid grows up to be a disadvantaged mother, often with early marriage, teenage pregnancies or starting off pregnancy with both micro- and macro-nutrient malnutrition; in turn she has a low birth-weight baby and poor pregnancy outcomes."
Sri Lanka's government has programmes that promote exclusive breastfeeding in the baby's first six months - recommended by the World Health Organization to boost a child's lifelong nutrition - and provide nutrients and supplements to vulnerable populations, including pregnant women, breastfeeding mothers and infants, in government clinics.
There are plans to "fine-tune" this breastfeeding promotion to target regions where malnutrition is high, said De Silva.
Education levels and mothers' knowledge about basic healthcare play a major part in determining their children's nutrition levels, said Kumari Navaratna, a senior health specialist at the World Bank's Colombo office.
"The primary caregiver for a child is the mother and evidence again and again is showing that if the mother is knowledgeable on appropriate feeding and caring practices, she is able to provide the best care to the child."
The Nutrition Society of Sri Lanka and Ministry of Health have advised taking into account regional economic and nutrition disparities as well as varying knowledge levels when tackling malnutrition.
Since May 2011 the government's National Nutrition Council has established a multi-sectoral pilot project in areas with high malnutrition, including Nuwera Eliya District.
District health, agriculture and livestock departments are designing regional nutrition interventions, including growth monitoring programmes and child-friendly clinics.
Government welfare policies dating back to independence in 1948 have largely failed to achieve long-term nutrition improvements, said Muttukrishna Sarvananthan, head of the Point Pedro Institute of Development in Sri Lanka and research fellow at Monash University in Australia.
"Government welfare policies should focus on the quality of outputs rather than the quantity of inputs, which has been the case hitherto."
To tackle malnutrition, policies have focused on handouts, such as nutritional supplements, without considering vulnerable groups' needs separately, or policy efficacy, said Sarvananthan.