Jan. 9, 2002:
Too Many Carbs In Your Diet?
Transcript: Nutrition Expert Dr. Walter Willett. ABC News
For more than a decade, the public health message has been loud and clear: Eat less fat and more carbohydrates. Millions of Americans have heeded the call.
But some doctors say too many Americans have gone too far in the switch to carbs.
Dr. Walter Willett, chairman of the department of nutrition at the Harvard School of Public Health, says it's not the amount of carbohydrates you eat but the type that matters. "What's become quite clear is that not all carbohydrates are the same," Willett tells ABCNEWS.
In his new book, Eat, Drink and Be Healthy, Willett rebuilds the U.S. Department of Agriculture Food Pyramid, which he says is based on "shaky scientific ground," replacing it with his own dietary guidelines.
A transcript of our live chat with Willett appears below.
MODERATOR at 11:56 a.m. ET
You have said the U.S. Department of Agriculture Food Pyramid is "tremendously flawed." Why?
The fundamental problem with the USDA dietary pyramid is that the main message says all types of fat are bad and we should eat large amounts of carbs and starch, including highly refined carbs.
We've known for decades that some types of fat are absolutely essential and many types of fat reduce blood cholesterol levels and the risk of heart disease.
However, there are some types of fat, particularly fats from red meat and dairy fat and trans fat from hydrogenated vegetable oils, that we do want to avoid.
From the standpoint of carbohydrates, we can become very fat if we eat too many of them. High amounts of carbs also reduce the levels of HDL cholesterol in the blood (the good cholesterol) and that can lead to higher risk from heart attacks.
Again, the form of carbs seems quite important in replacing highly refined starches, such as white bread and white rice, with the whole grain versions of these foods.
MODERATOR at 12:05 p.m. ET
Are there any other problems with eating a diet too high in carbs?
DR. WALTER WILLETT at 12:09 p.m. ET
Consumption of too many carbs that are refined or in the form of sugar can make it more difficult to control weight because these carbs are very rapidly absorbed which leads to high blood sugar levels followed by high surges of insulin.
After two or three hours, the large amounts of insulin bring the blood sugar levels crashing down, sometimes even below normal levels. At this point, people feel strong urges to look for snacks well before the next meal.
The kinds of breakfast people have been told are optimal, such as a bagel and jam which are fat-free, can cause this type of problem that over the long run can lead to excessive calorie intake and weight gain.
Also: Over many years, these powerful surges of insulin exhaust the pancreas to the point where diabetes can develop.
MODERATOR at 12:10 p.m. ET
Patty writes: "I've been hearing a lot about 40-30-30 referring to the type of calories you consume (I believe this 'plan' recommends that 40 percent of your calories come from carbs; 30 percent from fat; 30 percent from protein). Do you agree with that? Does this truly get us closer to healthier eating?"
DR. WALTER WILLETT at 12:11 p.m. ET
The exact proportions of carbs, fat and protein are not nearly as important as consuming healthy carbs, healthy fat, and healthy sources of protein. If you do that, there's probably quite a bit of flexibility with the percentages. But 40-30-30 would probably be fine.
Interestingly, those numbers are pretty close to the Mediterranean diet, which is roughly 40-40-20, which has been associated with long-term excellent health.
MODERATOR at 12:12 p.m. ET
Sheree writes: "What is it about nuts that are so good? Protein? Low carbs?"
DR. WALTER WILLETT at 12:14 p.m. ET
Nuts are good, probably for several reasons. Most importantly, the type of fat in nuts is almost all unsaturated, and therefore nuts lower blood cholesterol. There are now many studies showing they also reduce the risk of heart attacks.
Nuts are also big sources of a number of vitamins and minerals, so they contribute to a good diet in many other ways.
MODERATOR at 12:14 p.m. ET
Jim asks: "After reading about the glycemic index, I come away with a thought that a baked potato or a bowl of fat free pretzels are worse than say a tablespoon of sugar. Am I right in my conclusion?"
DR. WALTER WILLETT at 12:20 p.m. ET
It's probably true that if we only looked at the glycemic index, a baked potato or bowl of fat-free pretzels would be worse than pure sugar. However, the differences are not very great, and these are all things we should be trying to minimize in our diet.
In judging a source of carbohydrates, we should look at things in addition to the glycemic index such as fiber and the vitamin and mineral content.
For example, choosing a whole grain form of pasta versus pasta made from refined wheat or whole grain bread instead of white bread are healthy choices, even if the difference in glycemic index between these foods is small.
MODERATOR at 12:20 p.m. ET
A question from Lisa: "Would you recommend the Atkins program?"
DR. WALTER WILLETT at 12:23 p.m. ET
Many nutritionists have discarded the Atkins diet because it is so different from USDA recommendations. However, there are so many individuals who have experienced benefits in terms of weight loss by using this diet that I think it deserves long-term study.
We clearly have seen that many individuals do benefit by lower consumption of carbs, so I suspect there really is value in greatly reducing them.
However, I think there is also strong evidence that high intakes of animal fat can be harmful and that replacing these with unsaturated fats would surely be beneficial.
MODERATOR at 12:23 p.m. ET
Ken says: "Do you believe government suggested nutritionary guidelines should be set by another agency other than the Department of Agriculture due to the conflict of interest they have with promoting and helping grain producers, hence the push that Americans consume more grain-based products."
DR. WALTER WILLETT at 12:25 p.m. ET
I think there is a serious problem with the dietary pyramid being under the control of the Department of Agriculture because the influence of agro-business, for example the meat and dairy industries, are so powerful.
It would definitely be better for the pyramid to be the responsibility of the National Institutes of Health or possibly a nongovernmental organization.
MODERATOR at 12:25 p.m. ET
Ronan says: "Soon after finishing a 'balanced diet' meal, cravings for 'm-o-r-e- of anything' are overwhelming. My husband and I can be found standing with the refrigerator or cupboards open, looking for something that will stop the cravings. We keep popcorn, peanuts, no-fat dips, low fat crackers, gum, etc., or even an occasional ½ cup of frozen yogurt or ice cream and they do not satisfy. Any suggestions?"
DR. WALTER WILLETT at 12:28 p.m. ET
It's not totally clear what is meant by a "balanced meal." But there is now good evidence that eating meals that have a lower glycemic index and a lower carbohydrate content will delay the return of hunger and craving for snacks.
Alternative meals would include eating starches only in the form of whole grain foods such as brown rice or coarse, whole grain bread and eating a higher percentage of calories in the form of healthy fats and healthy sources of protein. In my latest book, Eat, Drink and Be Healthy, I've tried to provide practical ways for people to make these changes.
MODERATOR at 12:29 p.m. ET
Miriam asks: "What carbohydrates do you suggest for people with severe wheat and gluten sensitivity or allergies?"
DR. WALTER WILLETT at 12:30 p.m. ET
Anyone with gluten sensitivity really needs to be under the care of a physician, often with the help of a dietitian. However, most people with this condition can consume carbohydrates as rice and oats.
MODERATOR at 12:31 p.m. ET
Michael Manchester writes: "A local doctor appeared on TV and said that 'we must drink milk' to protect ourselves from osteoporosis, and the Canadian government and most nutritionists continue to promote dairy consumption to the exclusion of alternatives. Yet I have read of research from doctors T. Colin Campbell, Frank Oski, John McDougall and others who challenge the necessity of dairy products. Can you discuss any research you have done on the topic and your results? Thanks."
DR. WALTER WILLETT at 12:34 p.m. ET
There's absolutely no nutritional requirement for milk per se. If you do think you need more calcium, calcium supplements are probably better than milk because they contain no calories, no saturated fat and are less expensive than dairy products.
Interestingly, many long-term studies have now examined milk consumption in relation to risk of fractures. With remarkable consistency, these studies do NOT show reduction in fractures with high dairy product consumption. The hype about milk is basically an effective marketing campaign by the American Dairy industry.
MODERATOR at 12:34 p.m. ET
Dr. Willett, any final thoughts for our audience?
DR. WALTER WILLETT at 12:36 p.m. ET
It's really worth spending three or four hours learning about the elements of a healthy diet because this can an have enormous impact on health and well-being.
Combined with not smoking and regular physical activity, healthy dietary choices could prevent more than 80 percent of heart disease, 70 percent of strokes, 70 percent of colon cancer and 90 percent of diabetes in this country.
MODERATOR at 12:37 p.m. ET
Many thanks to Dr. Walter Willett and all those who joined the live chat.
Moderated by ABCNEWS.com's Saira Stewart.
http://abcnews.go.com/sections/comm...lett020109.html
Too Many Carbs In Your Diet?
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