The widely held belief that drinking water during a meal helps curb hunger and makes us eat less may not tell the whole story. New research suggests that, under certain circumstances, drinking water while eating may actually be associated with greater food consumption.
Researchers at Cornell University examined how adults ate during meals and found that participants who drank more water while eating also tended to consume more food overall.
The study, published in the scientific journal Appetite, found that every additional 100 ml of water was associated with an average increase of around 40 grams of food, equivalent to almost 50 additional calories.
The researchers also observed that participants who switched more frequently between bites of food and sips of water tended to eat larger amounts.
Why might water encourage eating?
One possible explanation involves the way we experience taste during a meal.
As we continue eating the same food, the pleasure we derive from it gradually declines. This phenomenon, known as , is one of the mechanisms that can eventually contribute to stopping a meal.
Drinking water between bites may effectively refresh the taste sensation in the mouth, restoring the contrast and appeal of the food. As a result, the meal may remain enjoyable for longer, potentially encouraging people to continue eating.
Water may also act as a lubricant, making food easier to chew and swallow. This could make eating more effortless and potentially increase the speed at which food is consumed.
Researcher Paige Cunningham notes that the common idea that water simply “fills” the stomach and produces prolonged fullness may be overly simplistic. Water moves relatively quickly out of the stomach, meaning that any feeling of fullness it creates may not last very long.
The way we drink may matter too
The researchers also analyzed data from two previous experiments involving a total of 86 adults.
Participants were allowed to eat as much as they wanted of either beef chili or chicken tikka masala while drinking water during the meal.
Interestingly, those who drank their water more quickly ultimately consumed less food.
The researchers do not yet know why. One possibility is that it could be related to how long water remains in the mouth, while another is that it may simply reflect differences in the overall duration of the meal.
What do the findings mean?
The study does not establish that drinking water during a meal directly causes people to eat more. The researchers emphasize that further studies are needed to determine whether the observed association represents a genuine cause and effect relationship.
Nevertheless, the findings challenge the simplified advice that drinking more water during a meal will automatically make us eat less.
The results suggest that both the amount of water consumed and the way it is consumed may influence eating behavior. Further research will be needed to clarify the complex relationship between hydration, taste, eating speed and satiety.