By being sweet, you're going to be fat

Would you eat a bowl of sugar in the morning? Take out a 1/4-measuring-cup. Fill it with refined white sugar. Now eat it.

Because that's what you do to your body, if you stop at Dunkin' Donuts and have a bagel.

"A bagel and a bowl of sugar may taste different, but to the body they're virtually the same thing," said Dr. David Ludwig. "A bagel would do the same thing to blood sugar hormones and hunger several hours after eating it."

Ludwig treats childhood obesity at Boston Children's Hospital and he is stunned by America's consumption of empty calories. In fact, he says that the average convenience store is a nutritional disaster area.

"All sugar-containing foods aren't bad," he told CBS News correspondent Susan Spencer. "For example, an apple has its main calories come from sugar. But it's surrounded by fiber, so it digests slowly and keeps blood sugar under control."

Including refined sugar, high fructose corn syrup and artificial sweeteners, the average American wolfs down 142 pounds a year, or roughly 2 ½ pound a week. That is up 23 percent in the last 25 years, and is a major factor in soaring rates of obesity and diabetes.

"The problem is when we take sugars and concentrate and refine them, and serve them in massive amounts throughout the food supply," Ludwig said. "That's causing hormonal changes that in many people drive hunger, cause overeating, and increase the risk of diabetes and heart disease."

Nutrition labels can be deceiving. Sugar content always is listed in grams, but few people know there are 4 grams in a teaspoon and, unlike the listings for salt and fats, there's not a clue as to how many grams of sugar is too many.

What's the RightSize of sugar? The Agriculture Department recommends no more than 12 teaspoons a day; that is roughly one 12-ounce soda and a slice of bread.

Eating half a cup of sugar might well send anyone into sugar shock, says author Connie Bennett. The author of "Susar Shock!" claims sugar just about ruined her life.

"I was socked in by brain fog," she said. "I would have these horrible migraine headaches."

All seemed lost until her doctor diagnosed low blood sugar — hypoglycemia — and told her to lay off the sweets.

"I remember all of a sudden, after three days, I was like, 'Wow! I feel so good,'" she said. "It was as if the fog lifted, and then, after a few weeks, all my ailments disappeared."

Connie Bennett thinks it's time to put on the brakes.

"I tell people, 'Don't believe me, just don't believe me,'" she said. "'Then test it out for yourself. Go a week without sugar and refined carbs, or maybe even two weeks and then just watch yourself like a lab rat.'"