Just two months after she started working for her new employer in August, Anya saw her weight drop to 47kg - a loss of 9kg.
The 29-year-old domestic worker gets a slice of bread for breakfast, bread or instant noodles for lunch, and rice with only vegetables for dinner.
"I'd hide in the toilet and cry because I was so hungry and upset," said the Filipino, who did not want to give her full name. "I'm scared to ask for more food, because the auntie is always nagging about the peanut butter finishing so fast," she added.
While the malnourishment of foreign maids here is not a new problem, it might have grown worse, say advocacy groups.
As many as eight in 10 domestic workers who seek help from the Humanitarian Organisation for Migration Economics (Home) do not get enough food, said Ms Valli Pillai, its director of case work.
Home said it saw a 20 per cent rise in complaints about poor or insufficient food from 2012 to last year.
Mr John Gee, head of research at migrant workers group Transient Workers Count Too, said it gets cases of inadequate food on a "regular basis", noting that it is a "less obvious form of abuse".
Agencies claim that cases of hungry maids are rare, but The Straits Times did not have to look too hard to find examples.
Ms Grace Rondon, 28, lost 20kg in half a year after arriving in Singapore this January. The Filipino maid went from 94kg to 74kg toiling long hours with not enough to eat.
"If I'm hungry, I'd just drink water," she said, adding that she "didn't dare to ask for biscuits or more food because I was scared they would get angry or scold me. And they have cameras in the kitchen".
Food is a sensitive subject to broach, say employment agencies and activists. The kitchen may be well-stocked, but not necessarily accessible to the maid.