Sugar-sweetened beverages are contributing to America’s obesity problem. You’ve heard this before, right? But did you ever wonder HOW sugar turns to fat? What about high-fructose corn syrup? Is it better than sugar or does it cause the same problem? And real fruit juice… could this be a healthy alternative to sweetened drinks?
The sugar-fat connection
The digestive system breaks complex food into simple particles, which are absorbed through the intestinal wall and into the blood stream. In the case of carbohydrates and complex sugars, enzymes chop them into simple sugars, including glucose and fructose.
Glucose is an energy source for cells. So if your body has an immediate energy need (you are playing or exercising), insulin helps glucose into the cells. However, if your body does NOT have an immediate energy need (you are sitting still or taking a nap), glucose enters the liver. Some glucose is stored in the liver as glycogen, but the liver can only hold so much—the remainder turns into triglycerides and eventually stored as fat.
Fructose is different. Most cells can not use fructose as an energy source, so this simple sugar goes to the liver, which converts it to glucose (if there is an immediate energy need) or triglycerides and fat (if immediate energy is not needed).
So… as we consider our daily energy needs… and the level of physical activity many of us maintain these days… it’s pretty clear how sugar-sweetened beverages make us fat.
What about high-fructose corn syrup?
Turns out most sweetened beverages no longer contain sugar. Instead, food factories turn corn starch into a sweet additive called high-fructose corn syrup. Corn is abundant in the United States, and high-fructose corn syrup is a cheap alternative to imported cane sugar. But is it healthier? Look at the name. High-fructose. Remember, fructose turns to fat in the absence of high energy demand.
Real fruit juice must be better, right?
Not so fast. Check the ingredient list of your favorite fruit drink. Many contain high-fructose corn syrup! Sure, the colorful label proclaims, “contains REAL fruit juice.” And it’s true… there is some real fruit juice in there, but how much? The ingredient list reads in descending order, so the farther down the list you find juice, the less of it there is.
Some drinks contain 100% fruit juice and no added sugar. However, these still contain plenty of naturally-occurring carbohydrates and sugars. So if we don’t maintain a high energy state (run, jump, play!), they can still make us fat.
What then is a healthy alternative to sweetened beverages and fruit juice? You guessed it… water!
Should we avoid fresh whole fruit?
No. Whole fruit contains natural carbohydrates and sugars, but not as much as juice. After all, it takes a whole lot of fruit to fill a glass with juice. Whole fruit also contains dietary fiber, which curbs the appetite and results in fewer calories consumed.
We still need to use common sense
Fruit juice tastes good and is fun to drink. The key is to monitor and seriously decrease our intake, especially if obesity is a concern. Don’t substitute juice for a serving of whole fruit. And always check with your child’s doctor… some kids have special nutritional needs and others may need MORE calories, not less.
For more information on high-fructose corn syrup and fruit juice, be sure to listen to our PediaCast on the topic or if you have concerns about your child’s nutrition, contact Nationwide Children’s Center for Healthy Weight and Nutrition.