On Thursday’s CBS Early Show, correspondent Richard Roth reported on a new cancer study that found that obesity can increase the likelihood of getting cancer: "Aside from avoiding smoking, the report says that maintaining a healthy lifestyle is the most important thing you can do for cancer prevention. That means diet, physical activity, and weight management...The report recommends laws and policy changes by government, industry, and schools, from adding bicycle lanes to public roads, to banning junk food from vending machines."

Following Roth’s report, co-host Julie Chen spoke with Dr. Ezekiel Emanuel, an oncologist and brother of White House Chief of Staff Rahm Emanuel, and asked: "In light of this report, how big of a role do you think government should play in making sure Americans lead a healthier lifestyle?" Emanuel suggested: "...do you tax high fructose corn syrup in drinks that we know add calories and promote cancer?...we know that by better policies, we can encourage people to eat less and increase their exercise, which will have an effect, not just on cancer, but also heart disease and diabetes and other health-related activities."

Chen pressed Emanuel to be more definitive about the need for taxes on certain foods: "You say 'maybe do we tax them?' I mean, should we tax these manufacturers that are putting all these things in their products that make it taste good, but it's not good for us?" Emanuel replied: "There are other ways to do it besides taxing. But that is certainly one option that should be considered. In New York, they banned transfatty acids."

Emanuel even went on to compare taxes on junk food to the tax on tobacco: "You know, we've certainly gone a long way on the smoking front, and it's made a dramatic difference in this country. In 40 years we've cut the smoking rate in half. And we can do the same thing in terms of prevention, if we focus on diet and exercise." Chen went one step further, wondering if junk food should be banned all together from schools: "What about vending machines in schools? Should there be -- should we allow public schools to have vending machines?" On January 3, 2001, Chen was upset that junk food portions were being downsized: "So, I'm getting less chips, paying the same amount of money. Is that legal for them to do this?"

Agreeing with Chen, Emanuel declared: "...kids are not independent decision-makers. We know they're not the most rational people...And I think school is one place, I personally am disturbed that we allow these high fructose corn drinks, corn syrup drinks, and that we allow a lot of junk food in them."

Here is the full transcript of the segment:

7:00AM TEASE:

HARRY SMITH: Breaking news. A major study out this morning, one in every three cancer cases in the United States is actually preventable.

MARTIN WISEMAN: Together they, that is we, can help make reduction in cancer a reality.

SMITH: We'll tell you how you can stay cancer free.

7:02AM SEGMENT:

JULIE CHEN: First, a major new study out this morning says we can prevent cancer in our lives. Let's go to CBS News correspondent Richard Roth in London with the story. Richard, good morning.

RICHARD ROTH: Good morning, Julie. It's a joint study by leading American and British scientists. The authors are calling it the most systematic policy report ever on cancer prevention. And it's based on a review of existing studies about cancer risk and prevention. Aside from avoiding smoking, the report says that maintaining a healthy lifestyle is the most important thing you can do for cancer prevention. That means diet, physical activity, and weight management.

MARTIN WISEMAN [STUDY PROJECT DIRECTOR]: Your lifestyle, the ways of life that people follow are really dramatically important in determining their own cancer risk and, indeed, the different patterns of cancer that we found around the world.

ROTH: Overall, the study estimates about a third of the most common cancers in the U.S. could be prevented through lifestyle. It says that healthy eating, activity, and especially weight management, could prevent 38% of breast cancers in the U.S. and 45% of bowel cancers. Diet and exercise, of course, won't guarantee you won't get sick. Breast cancer survivor Jodie Cooper knows that.

JODIE COOPER: But it's very, you know, if it -- it's great if that helps prevent other cancers or cancers in other people. I think that's wonderful.

ROTH: The report recommends laws and policy changes by government, industry, and schools, from adding bicycle lanes to public roads, to banning junk food from vending machines. But it also stresses cancer prevention, like health generally, is hugely dependent on personal choices, including some very small decisions we all make every day from what kinds of food we bring home from the supermarket to where we go out to eat. And even to whether we get there by car or bike or on foot. Julie.

CHEN: So true. Richard Roth, thanks, Richard. Joining us from Washington is Dr. Ezekiel Emanuel, an oncologist and director of bio-ethics at the National Institutes of Health. Good morning, Doctor.

EZEKIEL EMANUEL: Thanks for having me.

CHEN: Thanks for being on the show. In light of this report, how big of a role do you think government should play in making sure Americans lead a healthier lifestyle?

EMANUEL: Well, we have to make options available, as the report said, whether you close off Central Park, or in Washington, Rock Creek Park, on the weekends and allow people to run or walk or ride their bike, that's important. Whether you encourage supermarkets that keep fresh vegetables in the inner city or make farmers' vege -- farmer's markets available. Those are government policies. Similarly, do you tax high fructose corn syrup in drinks that we know add calories and promote cancer? So those are government policies. And we know that by better policies, we can encourage people to eat less and increase their exercise, which will have an effect, not just on cancer, but also heart disease and diabetes and other health-related activities.

CHEN: You say 'maybe do we tax them?' I mean, should we tax these manufacturers that are putting all these things in their products that make it taste good, but it's not good for us?

EMANUEL: Well, I think that's a policy choice that we have to make. There are other ways to do it besides taxing. But that is certainly one option that should be considered. In New York, they banned transfatty acids. You know, we've certainly gone a long way on the smoking front, and it's made a dramatic difference in this country. In 40 years we've cut the smoking rate in half. And we can do the same thing in terms of prevention, if we focus on diet and exercise.

CHEN: What about vending machines in schools? Should there be -- should we allow public schools to have vending machines?

EMANUEL: Now you're asking me all these ethical questions and not medical questions.

CHEN: Well, let me turn to this, what-

EMANUEL: Well, the ethical-

CHEN: Yeah, go ahead.

EMANUEL: Well, from the ethical standpoint, you know, kids are not independent decision-makers. We know they're not the most rational people. We have lots of data on that. And so we need to encourage them and encourage healthy eating habits and healthy exercise habits. And I think school is one place, I personally am disturbed that we allow these high fructose corn drinks, corn syrup drinks, and that we allow a lot of junk food in them. They're used to raise money. But that doesn't seem to me to be -- that's a short of short-term gain, raising money, as opposed to a long-term harm of increasing obesity.

CHEN: Let me ask you about this, what about all the people out there who live right, they're not obese, and they still get cancer?

EMANUEL: Yes. I mean, as I think the report made quite clear, it's not a guarantee. There are lots of things that cause cancer. We know radiation and other things. So it's not -- diet isn't the only thing, but it is a very big component, about a third to 40% of cancers are related to diet and exercise. That's a very big component. And then smoking is another big chunk. So those three items, eating right and eating fruits and vegetables, exercising regularly, and not smoking, go a long way towards preventing cancer. It's not a guarantee, but it certainly reduces your odds of getting cancer dramatically.

CHEN: Dr. Ezekiel Emanuel, thank you. For more information on this new cancer study, go to our website, earlyshow.cbsnews.com.

—Kyle Drennen is a news analyst at the Media Research Center.