Many people believe that drinking water during a meal helps control appetite by filling the stomach before too much food is eaten.
This simple idea has been shared for years as a weight management tip. However, a new study from Cornell University suggests that the relationship between water and eating may be more complicated than many people think.
The research, published in the journal Appetite, found no evidence that drinking more water during a meal automatically leads people to eat less. Instead, participants who drank more water actually tended to eat more food. The findings challenge one of the most common pieces of nutrition advice about mealtime habits.
The study was led by Dr. Paige Cunningham from Cornell University together with Dr. John Hayes from Pennsylvania State University. The researchers analyzed data from two earlier laboratory studies involving 86 adults. Participants were served either beef chili or chicken tikka masala with water and were allowed to eat as much as they wanted while every bite and sip was recorded on video.
When the researchers examined the recordings, they found that every extra 100 grams of water people drank was linked to about 39 additional grams of food eaten, equal to roughly 49 extra calories. They also noticed that people who frequently switched between taking bites of food and sips of water tended to eat even more than those who switched less often.
The scientists believe this may be related to a process called sensory-specific satiety. Normally, as people continue eating the same food, it gradually becomes less appealing and they naturally stop eating. Alternating food with water may refresh the eating experience and delay this natural loss of interest, allowing people to continue eating for longer.
Another possible explanation is that water keeps the mouth moist and makes swallowing easier. This may allow people to eat more comfortably and enjoy the meal for a longer time. Because water also leaves the stomach quickly, it may not create a lasting feeling of fullness during the meal.
Interestingly, one finding surprised even the researchers. People who drank their water more quickly actually tended to eat less overall. The scientists are not yet sure why this happened and say it could be related to how long meals lasted or other factors that were not directly measured.
The research team also carried out a second study exploring whether spicy foods change eating behaviour. The results were published in the journal Food Quality and Preference. In this experiment, 49 adults ate tortilla chips with either a mild or spicy salsa, with the only difference being the amount of cayenne pepper in the salsa.
The spicier salsa reduced the total amount of food eaten by about 28 percent. Participants also ate around 30 percent more slowly, suggesting that the heat encouraged slower eating, which naturally reduced food intake. Importantly, people did not drink more water with the spicy salsa, showing that the lower food intake was not explained by greater water consumption.
The researchers say these findings should be interpreted carefully because the studies were performed in a laboratory using only a small number of foods.
More research is needed to see whether the same effects occur with different meals and in everyday life. Still, the studies highlight that small changes in eating habits, such as the way we drink water or the amount of spice in our food, may influence how much we eat without us even noticing.
These studies challenge two popular beliefs—that drinking water during meals always helps people eat less and that spicy food encourages overeating. While the findings are interesting, they show only associations under controlled laboratory conditions and cannot yet prove cause and effect.
Larger real-world studies will be needed before changing dietary advice, but the research offers valuable new ideas about how eating behaviour can be influenced by simple changes at mealtimes.
If you care about weight, please read studies about diet that can treat fatty liver disease, obesity, and hop extract could reduce belly fat in overweight people.
For more information about weight, please see recent studies about how to curb your cravings for ready-to-eat foods, and results showing what you can eat to speed your metabolism up.
Source: Cornell University.
