Every since you were a kid, you've always been told that sugary sweets will rot your teeth. So it doesn't really come as a surprise that a new study from the U.K. finds that greatly reducing the amount of added sugar you eat can significantly lower your risk of dental decay.

Researchers found that over time, people's risk of cavities increased incrementally as the consumption of free, or added, sugars grew from about 0 percent to 10 percent of total daily calories. So for healthier teeth, the study authors recommend cutting the amount of added sugars to no more than 5 percent, with a target goal of 3 percent.

That 5 percent figure is one fifth of the daily limit suggested by the Institute of Medicine. And it represents half of what the World Health Organization (WHO) currently recommends--though it has recently proposed guidelines that would cut its max to 5 percent, too. This includes any sucrose, glucose, and fructose added to food, as well as the sugars present in honey, syrups, and fruit juices. (There's a lot to smile about--except for the smiles themselves. Find out how your hometown ranks among America's Best and Worst Cities for Teeth.)

Let's take a closer look at what 5 percent really means: A guy eating 2,000 calories a day would be limited to just 100 calories, or 25 grams, of added sugar. So drink one glass of orange juice with breakfast, and you've pretty much hit that cap for the day. That means no honey-sweetened oatmeal or fruit-flavored Greek yogurt later on.

Why You Don't Need To Sugar-Strike
But as it turns out, it's not exactly how much sugar you're eating that bumps up your tooth decay risk--it's how often you're eating it, says Carole Palmer, Ed.D., head of the division of nutrition and oral health promotion at the Tufts University School of Dental Medicine.

That's because of how the decaying process works: Bacteria attach to your teeth and coat them in a thin film known as plaque. When you eat sugars, they reach the bacteria, which begin to chow down. They then turn the sugars into acid, which deconstructs the enamel of tooth and causes decay. (Coffee can stain your pearly whites but it may help your mouth stay healthy. Learn How Coffee Can Save Your Teeth in your next cup o' joe.)

The acid reaction starts each time sugar comes in contact with plaque. If you glug down a sweet drink quickly, the excess sugar beyond what the bacteria can use is simply swallowed. So when looking at tooth decay, it doesn't really matter if you're drinking a cup of sweetened coffee with one teaspoon of sugar or 10--the decaying potential would be the same. (For solids like cookies or cake, however, the leftover particles stay in your mouth for the bacteria to continue to munch on, says Palmer.)

What matters most, though, is if that same cup of Joe lingers from 9 a.m. to lunchtime.

“As long as you're sipping it or snacking on it, the bacteria that can cause decay are changing that sugar into acid, and that acid is eroding the tooth,” Palmer says. (Here are the 5 Surprising Ways You're Destroying Your Teeth--and the best ways to protect them.)

The best thing to do? Eat your sugary foods during your three main meals--the decaying reaction would be sparked then anyway, because there are natural sugars in healthy foods like fruits, vegetables, and grains. Then brush after, advises Palmer.  

Try not to graze on sweetened food or drinks throughout the day, but if you do, give your mouth a quick rinse after. That'll flush out the extra sugar that's hanging out there hoping to feed the bacteria later.

How Much Sugar Should You Eat?
Look at it from a health and body composition standpoint, since the total amount of sugar you eat isn't what will rot your chompers. The 5 percent recommendation from the study isn't realistic or sustainable for most guys to incorporate in their everyday life-- and it's unnecessarily low from a general health standpoint, says Men's Health nutrition advisor Alan Aragon, M.S.

A more realistic goal: Shoot for a maximum of 10 percent of your daily calories to come from added sugars, Aragon advises.  (For more great ways to lower you sugar consumption, follow these 6 strategies to curb your habit.)