Mind over matter: Quench summer thirst, but measure beverage calories

July 9, 2012

WEST LAFAYETTE, Ind. - People need to stay hydrated as summer temperatures soar, but consumers should be aware that calories can quickly add up when you drink to cool down, says a Purdue University nutrition science expert.

"Beverages can be an important source of energy, and those calories can add up quickly when the warm weather prompts people to drink more often," says Richard D. Mattes, distinguished professor of nutrition science. "It is critical that people are properly hydrated during hot weather. Fortunately, there are many affordable and palatable no-calorie and low-calorie beverage options to meet the need. When drinking a beverage with energy, measured by calories, consumers need to consciously monitor the calories and adjust their diet or physical activity levels. Otherwise, those calories will add to each day's total and can lead to a gain of body weight."

Most experts agree that beverage consumption influences body weight, but there are still questions about how these liquid calories make a difference.

"Are all calories treated equally by the body? The emerging clear answer is, no. Energy from beverages does not produce as strong a satiety response - feeling full - as solid foods. Consequently, people may consume a large amount of energy before realizing they have done so," says Mattes, who also is director of the Ingestive Behavior Research Center at Purdue. "Over time, human drinking has transformed from a behavior that just meets hydration needs to one that also contributes substantively to energy needs and probably surpluses. About 20 percent of our daily energy intake is from beverages, and, from an evolutionary perspective, that is a radical change in our dietary behavior. For example, wild primates obtain about 80 percent of their daily water needs from food by eating succulent plants. Humans now consume about 80 percent of their daily water from beverages."

Another dramatic change with today's eating habits is a greater eating frequency, often referred to as snacking, Mattes says.

"The more often you eat, the more likely you are to have higher energy intake and gain weight," he says. "Today, 40 percent to 50 percent of snacking involves beverages. Because this source of energy has weak effects of appetite and is often consumed at non-meal times, beverages propose a unique challenge to weight management."
Writer: Amy Patterson Neubert, 765-494-9723, apatterson@purdue.edu

Source: Richard D. Mattes, 765-494-0662, mattes@purdue.edu