Two patients are reported to have died and five more came to "significant harm" after people with swallowing difficulties were given inappropriate food, according to NHS Improvement.
The regulator received reports of hash browns, mince and sponge cake being fed to patients in England who were supposed to be on liquidised food.
Hundreds of choking or coughing incidents also occurred from 2015-17.
Experts are now calling for an end to the term "soft diet".
NHS Improvement, the Royal College of Speech and Language Therapists and the British Dietetic Association say the term can cause confusion among staff, patients and carers.
'Avoid further harm'
Dr Kathy McLean, executive medical director at NHS Improvement, said: "Vulnerable patients have died or been harmed because there is confusion in the way people describe what type of food is suitable for those with swallowing or chewing difficulties.
"We are calling on everyone providing NHS-funded care to start using precise terminology to help avoid further harm.
"This will help save lives and make the NHS safer," she said.
Patients who have swallowing difficulties, known as dysphagia, or difficulty chewing need food which is soft, minced, pureed or liquidised.
Some people with the condition can't swallow at all and some have problems swallowing certain foods or liquids.
It can affect people of all ages and is often caused by another health condition such as stroke, head injury, multiple sclerosis or dementia.
NHS Improvement now wants all NHS staff to use clearly categorised food textures - as published by the International Dysphagia Diet Standardisation Initiative - to make sure patients are fed safely and correctly according to their individual needs.