A couple who starved their maid for more than a year and caused her weight to plummet from 49kg to 29.4kg will have to serve longer jail terms, following an appeal by the prosecution.

Yesterday, housewife Chong Sui Foon, 48, had her jail sentence raised from three months to 10.

Her husband, freelance trader Lim Choon Hong, 48, will also have to serve 10 months in jail, instead of his original sentence of three weeks in jail and a $10,000 fine.

The original sentences handed down by a district court in March were "patently and manifestly inadequate", said Chief Justice Sundaresh Menon, as he allowed the appeal.

He said the couple subjected Filipina Thelma Oyasan Gawidan to "systematic cruelty and denial of her basic human dignity".

The Chief Justice said there was no difference in their culpabilities.

He noted that Chong was the "active perpetrator" who restricted the maid's meals to slices of bread and instant noodles for 15 months, in what he described as a "bizarre feeding regime".

But Lim, as the registered employer, was equally culpable. Lim had the legal duty to safeguard the victim but, though he had full knowledge of what was going on, "turned the other way and allowed the cruelty to continue", said Chief Justice Menon.

However, he did not accept the prosecution's submissions seeking the maximum one-year jail term for the couple.

The Chief Justice said that although the acts were cruel and Chong had no explanation, this was not a case of cruel acts being done "purely out of gratification", which would make it even more egregious.

He also gave some weight to the $20,000 in compensation the couple paid to the maid, though he noted it was done in part to avoid a harsher sentence after they pleaded guilty. The couple initially offered $10,000, but the maid asked for $20,000, the court heard.

Madam Gawidan, now 42, has since returned to the Philippines.

CJ Menon allowed the couple to stagger their sentences in the interest of making acceptable arrangements for their three children.

Chong will begin serving her sentence first, and Lim will go to jail one week after she is released from prison.

While working for the couple, Madam Gawidan was given two meals a day, largely made up of plain white bread, tap water when she asked for a drink, and instant noodles. Chong did not allow her to buy food or eat any other food at home.

The maid lost 40 per cent of her body weight, stopped menstruating and suffered hair loss.

She finally fled from the couple's eighth-storey apartment at The Boulevard Residence condominium in Cuscaden Walk on April 19, 2014.

In March last year, Lim pleaded guilty to failing to provide Madam Gawidan with adequate food. Chong pleaded guilty to abetting his offence under the Employment of Foreign Manpower Act.

In mitigation, the defence argued that Chong's obsessive compulsive disorder led to the acts, but the trial judge said her mental condition had no link to the offence.

According to the Manpower Ministry, the couple have been permanently barred from hiring maids.