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.
Unlike in Hong Kong, where employers are legally obliged to provide free food or give a monthly food allowance of HK$964 (S$158), Singapore's Ministry of Manpower says only that employers should provide "adequate food". But observers say it is debatable how much is "adequate". Also, should the onus be on maids to ask for more food or should employers be more sensitive to the needs of maids.
Homekeeper's managing director Carene Chin said maids should be "smart enough" to ask for an extra helping of food.
"If you're scared and don't dare to ask, you should not complain that your employer is not kind enough," she said, adding that maids can always stock up on extra food on their days off.
But Home executive director Jolovan Wham said employers give maids "psychological stress" when they hint that the rice is disappearing fast. "They are afraid of losing their jobs as the employer can repatriate them easily."
And there is some misunderstanding on employers' part about how maids seem to eat a lot of rice, say observers.
Employers and workers told The Straits Times that maids generally eat two to three times more rice and bread than their employers, as they need the carbohydrates for their physical chores.
Home's Ms Valli said employers "have to see to [the maids'] needs first and give them time to adjust, instead of saying, 'This is Singapore, get used to it' ".
While Anya still struggles with hunger pangs, Ms Rondon could not bear them and asked to go home after six months; all her salary went towards paying off fees owed to her agent.
But she is back in Singapore, working for another family and feels "so happy to be fed again".