The Healthcare Commission (HC) is to investigate care of the elderly following an increase in the number of patient complaints.
The health watchdog has confirmed that a series of inspections will be carried out in primary care trusts to ensure that the required nutritional levels are being provided and that patients are being treated with dignity.
Chief executive Anna Walker insisted that the "vast majority" of NHS staff do an "excellent job" of looking after patients, but that some patients are not being treated with the dignity and respect that they deserve.
"That is simply unacceptable in the modern NHS," she insisted.
The Conservative party has alleged that just £118,000 of the £67 million set aside for the government's dignity in care initiative has been spent, even though four months have passed since it was announced.
"Those who need looking after will continue to suffer as long as the government dodges the more important question of sustainable long term funding for social care," said shadow health minister Stephen O'Brien.
Independent advice on private healthcare