Drinking water in the middle of a meal may actually increase the amount of food a person can eat, according to a new study that challenges a well-established tip for weight loss.

Taking sips of water between bites has long been thought to help people cut down on calories by creating a sense of fullness before too much food is consumed.

However, a growing body of studies suggests this assumption might be wrong.

Previous studies have observed that people with obesity spent more time drinking during meals, drank at faster rates, and had a more even distribution of sips over the course of a meal compared to leaner individuals.

Now, a new study shows that greater water intake is associated with more food intake at a meal, not less.

Researchers from Cornell University found that participants actually consumed about 40 additional grams of food, or nearly 50 more calories, for every extra 100ml of water they drank.

People who alternated more often between eating and drinking also consumed more food, according to the study published in the journal Appetite.

Scientists suspect the water refreshes the sensory contrast on the tongue and makes food remain enjoyable for longer, postponing the point when one wants to stop eating.

“There’s been this widespread advice that if we drink water, it fills us up... But water is emptied quickly from the stomach so it likely doesn’t fill us up for long,” said Paige Cunningham, an author of the study from Cornell University.

“Instead, water may increase how much we eat, providing lubrication which can speed up eating, and preventing a dry mouth which can prolong enjoyment of the food,” Dr Cunningham said.

In the study, researchers also assessed data from two earlier experiments involving 86 adults, in which the participants received either beef chilli or chicken tikka masala with water and ate as much as they wanted.

They found that people who consumed their water more quickly ate less food.

This pattern might be linked to how long water remains in the mouth, or simply reflect the total duration of the meal, scientists say.

“We are following up on this right now so we can make those causal inferences,” Dr Cunningham said.

“Overall, individuals ate more when they drank more and switched between bites and sips more often, highlighting the potential influence of water and drinking behaviours on food consumption,” scientists concluded.

The findings challenge widespread dietary advice to drink water with meals to reduce food intake.