A survey of 156 ready-made salads and pasta bowls from coffee shops and fast-food restaurants found that while the overall average of salt levels was healthy — 1.4 grams — nearly a fifth (19%) had more than the 2 grams recommended for a meal.

The saltiest salad in the survey by Consensus Action on Salt and Health — the Thai noodle bowl from EAT — had 4.4 grams of salt for every portion, nearly three quarters of the total recommended daily salt intake of 6 grams.

CASH said some salads should carry health warnings rather than manufacturers marketing them as healthy meals.

The research found the McDonald’s crispy chicken Caesar and grilled chicken Caesar contained 3.5 grams and 3.3 grams of salt for every portion, respectively — more than the supposedly less healthy Big Mac and small fries, which contains 2.5 grams of salt.

Graham McGregor, a professor of cardiovascular medicine and chairman of CASH, said cutting salt intakes would save thousands of lives.

He added: “Many people think of a salad as a healthy lunch. Saving 2–3 grams of salt a day may not sound like a lot, but research shows that people who reduce their salt intake by this sort of amount can reduce their risk of having a heart attack or stroke by a quarter.”

McDonald’s said much of the salt in its chicken Caesar salads is made up in the low-fat dressings and that the salty elements were provided separately to give consumers a choice.