When it comes to keeping hunger at bay, exactly which foods
you choose to eat — and not eat — are a key part of controlling the urge to
eat.
Science shows that it's not always enough to simply eat when
you're hungry — we've all experienced the sensation of feeling hungry when it
seems like we just ate a meal.
Indeed, researchers say, the foods you choose have an
impact on how long you'll continue to feel full after you eat. Here are the
best — and most healthful ways — to fill up, according to the experts. [The
Science of Hunger: How to Control It and Fight Cravings]
Low-calorie-density foods
"Low-calorie-density foods" may sound like a
mouthful (and, well, that's the point!), but the important thing is that these
are foods that take up a lot of space in your digestive system but don't pack a
lot of calories into each bite.
"Low-calorie-density foods are what you want to encourage
to help people fill up on fewer calories," said Barbara Rolls, chair of
nutritional sciences at Pennsylvania State University and author of "The
Ultimate Volumetrics Diet" (William Morrow Cookbooks, 2013).
These foods are the opposite of, for example, high-fat
foods, which are very calorie-dense, meaning they pack a lot of calories into
each bite, Rolls told Live Science.
Low-calorie-density foods include water-rich foods, such as
fruits and vegetables. They have fewer calories per bite, but a lot of volume,
she said. Other good examples of low-calorie-density foods include broth-based
soups, and salads, Rolls said.
One of the reasons these low-calorie-density foods help
fill you up is your perception of how much you are eating.
Perception is a big part of satiety, or the feeling of
fullness, Rolls said. People who eat low-calorie-density foods perceive that
they are eating more food than people who consume the same number of calories
from high-calorie foods. Therefore, eating low-calorie-density foods can lead
to increased feelings of fullness, she said.
Melinda Manore, a professor of nutrition at Oregon State
University, agreed that low-calorie-density foods are a good way to fill up.
These foods take up space in the gut — so the body
registers that it's being fed, and you get a sense of fullness without as many
calories, Manore told Live Science.
Fiber
Fiber-rich foods
are also filling, but for different reasons than the low-calorie-density foods.
It turns out that feeling full is just one part of not feeling hungry.
"Fiber is thought to have other effects" that
help keep hunger away, Rolls said. It not only keeps you feeling full but also
adds texture and body to foods as you eat them, changing the way food feels in
your mouth, which can also prevent you from feeling hungry right away, she
said.
In addition, fiber moves slowly through the digestive
tract, so it slows down the digestive process, Rolls said. It also may have
more potent effects on some of the satiety hormones in the body, Rolls said. In
other words, fiber may have a stronger effect on the hormones that signal
fullness.
Protein
And what about protein, which some experts say is the most
satiating type of food?
Researchers have known for a long time that eating protein
can suppress appetite a bit and, as a result, cause people to eat less, Manore
said.
But there are still some questions about protein's filling
effects.
Some research suggests that protein keeps people feeling
full longer than other nutrients do, but other research suggests that isn't the
case, Rolls said. But in general, experts do think that eating protein can help
with satiety, she said. (There's still debate over what types of protein are
best and how much a person should eat, she added.)
Part of protein's filling effects could be psychological,
Rolls said. People are used to thinking of protein as the center of a meal, and
if the meal doesn't have any protein, a person may not perceive it as
satisfying, she said.
What about water?
Downing a glass of water before a meal certainly seems
like it would fill you up, but experts still don't agree on the answer to this
one.
Some studies have shown that drinking water before a meal
may affect satiety a bit, but it's possible that there's a psychological
effect, too, Rolls said. For example, if people believe that drinking water
before a meal will lead them to eat less, that may well be the case, she said.
On the other hand, drinking water does distend your
stomach, which can make you feel full, Manore said. But the body doesn't
register liquids the same way it does solid foods, she said. For example, if a
person drinks a martini with 300 calories before a meal, that person wouldn't
necessarily eat 300 fewer calories at dinner, she said. [Cheers?
Counting the Calories in Alcoholic Drinks]
In one interesting study by Rolls and her team, people were
given either a glass of water and a vegetable stew, or a soup made from the
same amount of water and stew, mixed together. The researchers found that when
people were given the soup, they ate fewer calories overall than when they were
given the glass of water and the stew