Settle down class, Dr. Oz is beginning a series of homework assignments for you—called Prescription America—that he says are critical to your health and the health of your loved ones.

Whether you call them "sodas," "pops," "tonics" or "soft drinks," Dr. Oz's first assignment for you is to cut these sugary drinks out of your life for two weeks.

"The entire obesity epidemic, according to all the long-term studies we've done, comes down to [consuming] 100 calories less in a day. That's it," he says. "Now a soft drink usually has about 160 calories. Plus, on average, you'll eat an extra 125 calories at the meal you're having with the soft drink. If you can just cut out that soft drink, then you're going to be able to lose an estimated 15 pounds over the course of a year."

Fortunately, Dr. Oz is allowing some substitution options. If you love the fizziness of soda, you can drink other nonsugary carbonated beverages. If you're addicted to the caffeine, try switching to coffee or green tea, which he says are much healthier options.

"We've got to break those habits that you've formed," Dr. Oz says, "to remind you what life should be like."