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Shantanu Nundy, MD  
Male
Chicago, IL

Specialties: Preventive Health, general medicine

The University of Chicago Primary Care Group
Department of Internal Medicine
773-702-0240
Chicago, IL
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A Food-Based Approach to Eating

Feb 22, 2011 - 8 comments
Tags:

Nutrition

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Healthy Eating

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carbohydrates

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saturated fat

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Protein

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food

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Diet

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Fruit

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Vegetables

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Vitamins

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Minerals

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food science

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dietary guidelines

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dietary guidelines americans



The science of nutrition is changing and not in the way you might expect. After years of “reductionist” thinking — where food has been viewed as the sum of its parts – a call to treat food as food has been sounded. No more poring over nutrition labels to calculate grams of fat or chasing down the latest go-to chemical – be it vitamin E, fish oil or omega-3. Instead we are being asked to call a potato a potato and a piece of steak… well… a piece of steak.

If you haven’t heard about this sea change yet, you are not alone. The food science industry that markets “food products” for our consumption has done a good job giving their laboratory creations a semblance of health with phrases like “low fat” and “high in vitamin C”. For our part, the medical community is also to blame. Despite evidence to the contrary, we have been slow to renounce the “fat is bad” mantra or break away from the nutrient-based approach to eating that first swept the country over 30 years ago.

Until very recently, the dissenting opinion was expressed mainly by food journalists and self-proclaimed naturalists. In the book "Good Calories, Bad Calories," Gary Taubes argues persuasively that the science behind vilifying fats is fatally flawed and proposes that carbohydrates, and in particular sugar and high fructose corn syrup, are the real bad guys. Michael Pollan, perhaps the best quoted food journalist-turned-activist, goes further to suggest the whole notion of understanding food by its constituent parts – fat, protein and carbohydrates or even saturated fats, unsaturated fats, and trans fats – is plain wrong. He opens "In Defense of Food" with three dictums for healthful eating: “Eat food. Not too much. Mostly plants.”

Now the scientific and medical literature is coming around. A review in the Archives of Internal Medicine of over 500 trials found “insufficient evidence” that the intake of dietary fat (except for trans fat) is associated with coronary heart disease.(1) More recently, an editorial published in the Journal of the American Medical Association (JAMA) August 2010 entitled “Dietary Guidelines in the 21st Century – a Time for Food” writes “little of the information found on food labels’ ‘nutrition facts’ panels provides useful guidance for selecting healthier foods to prevent chronic disease.”(2)

Don’t let the plain academic language lull you – what these scientists have published in arguably the world’s most prestigious medical journal is that the entire approach to food based on nutrients is wrong.

It’s not that eating the right nutrients is hard (how are you supposed to know if less than 30% of your calories comes from saturated fats?) and that the science of nutrient-based eating is bad (this is too academic to get worked up about), it’s that our focus on nutrients has actually made our food MORE unhealthy. In an effort to engineer “better” foods, we created trans fats, which we now know are deleterious to health, and food products that are low in fat but high in dough conditioners (whatever that is). Indeed, as saturated fat consumption has decreased, our collective burden of chronic disease and obesity has only increased.

So if fat is not bad, and we shouldn’t be thinking about food in terms of individual nutrients, what are we left with? Surprisingly, we are pretty much where we were in our grandparents’ generation, a time before we thought we could improve health by manipulating individual nutrients, and when food was just food. As the JAMA article concludes “… although this approach may seem radical, it actually represents a return to more tradition, time-tested ways of eating.”

In fact, the most convincing studies of dietary patterns that prevent or retard chronic disease are food-based. Fruits, vegetables, whole grains, and nuts have been consistently associated with lower risk of disease while fish consumption has lowered the risk of death from heart disease. And these effects are above and beyond what you see from diets with equal levels of protein, fat, and carbohydrates.*

A food-based approach to eating is not only healthier but also easier. Instead of worrying about things you can’t see, smell or taste; it asks you to pay attention to what you are putting in your mouth. It supports an eating plan of fruits and vegetables, whole grains, and unfettered meats over processed foods, packaged meats, and sugar-laden beverages; and favors home-cooked food over store-brought or restaurant meals.

So the next time the hunger pangs strike, check your energy bar at the door and drive on by the local diner. Instead go to your local grocery store, buy yourself some fresh food, and prepare yourself a hearty, wholesome and healthy meal.


- Shantanu Nundy, M.D.


*It’s not hard to imagine why. Fish has way more in it than protein, different types of fat, and carbohydrates; and even if we could categorize every vitamin and micronutrient in fish we wouldn’t yet understand how these nutrients work synergistically to impact health.

1 Mente A, de Koning L, Shannon HS, Anand SS. A systematic review of the evidence supporting a causal link between dietary factors and coronary heart disease. Arch Intern Med. 2009 Apr 13;169(7):659-69.

2 Mozaffarian D, Ludwig DS. Dietary guidelines in the 21st century–a time for food. JAMA. 2010 Aug 11;304(6):681-2.

Dietary Guidelines 2010: A Worthwhile Read

Feb 15, 2011 - 0 comments
Tags:

Nutrition

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dietary guidelines americans

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USDA

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Healthy Eating

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Overweight

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Weight Loss

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calories



In case you missed it, Dietary Guidelines for Americans, 2010 was published this month.(1) Commissioned by law, the Dietary Guidelines are revised and published every 5 years as a joint effort between the U.S. Department of Agriculture (USDA) and the Department of Health and Human Services (HHS) based on an expert panel review of the most recent data on health and nutrition. For a nation obsessed with dieting and weight loss, and in the midst of an epidemic of obesity, diabetes, and chronic diseases, the release of the latest national nutrition guidelines has come with limited fanfare and media attention.(2,3)

A large part of the problem is that over the years we have been conditioned to pay little attention to these reports. Although the effort put forth by scientists in generating the report is impressive, many of their key conclusions are either obvious or old news. A key finding of this year’s report is to eat less and maintain calorie balance (shocker!). Other recommendations are outdated or more controversial than the authors suggest. While the dangers of saturated fats are accepted as dogma, the body of evidence supporting this assertion is surprisingly weak, leading some experts to dismiss or even reverse the recommendation to reduce the consumption of saturated fats.4 Finally, those recommendations that are evidence based are difficult to act on, such as the report’s plea to consume “less than 300mg per day of dietary cholesterol” (calorie counting is notorious difficult, let alone milligrams of cholesterol). As a result, we have come to believe that we are more likely to get up to date, factual, and easy to follow advice from a celebrity magazine at the checkout counter than we are from our own government and leading scientists.

Underpinning the above is the simple fact that the Dietary Guidelines is not only a scientific document, it is also a political one. Given its primary role in protecting U.S. agricultural interests, including the powerful food industry lobby, the USDA is hardly an impartial source. Thus this year’s report marks the first time specific food items are named such as “pizza” or “fried white potatoes” despite the well-established deleterious effects of these foods. And we still are waiting to be formally admonished against eating processed and packaged foods and instead are simply told to eat foods lower in salt, added sugars, and saturated fats (all of which food industry products are exorbitantly high in).

Despite all the caveats above, I highly recommend reading Dietary Guidelines 2010 in its entirety. Regardless of where you fall on the low-fat versus low-carb debate, or whether you are an ardent supporter of Michael Pollan and local farmers, the report provides a critical summary of where we stand as nation on our most pressing public health problem. If we are to have any hope of reversing the tide of the obesity and chronic disease epidemic, we as a nation must educate ourselves about the nature of the epidemic and the choices we make that fuel it.

Consider the data table below showing the top 25 sources of calories among Americans (taken directly from the report):(3)

The table shows that the number 1 source of calories for Americans across multiple age groups is grain-based desserts (e.g., cake, cookies, pie, donuts, pastries). Pause on this for a moment. More of our calories are coming from desserts than any other food? And yet how often it is that we hear people ask, “Why do I keep gaining weight?” Though the answer for specific individuals may vary, as a nation the answer is clear. Among children ages 2 to 18 pizza and soda/energy/sports drinks are ranked 2 and 3, respectively. Regardless of your nutrition beliefs I suspect you are appalled by the notion that we are raising our children on a diet of dessert, pizza, and sodas.

Dietary Guidelines 2010 is filled with illuminating figures and text like the table above that help create a portrait of what Americans are eating and what the health consequences are. Sometimes the most powerful behavioral motivation is simply holding up a mirror to ourselves, and this report can serve as that mirror.

America, Dietary Guidelines was written for you with your tax dollars, so you might as well read it. But just this once, don’t forget to sprinkle a few grains of salt on it first.

- Shantanu Nundy, M.D.


1 http://www.health.gov/dietaryguidelines/

2 article in NY Times, http://www.nytimes.com/2011/02/01/business/01food.html

3 good editorial from NY Times, http://opinionator.blogs.nytimes.com/2011/02/08/is-eat-real-food-unthinkable/

4 http://beyondapples.org/2009/08/20/are-we-getting-nutrition-all-wrong/

5 page 3, http://www.health.gov/dietaryguidelines/dga2010/DietaryGuidelines2010.pdf


Diagnosing Diabetes Easier

Jan 24, 2011 - 5 comments
Tags:

Diabetes

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HbA1c

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Blood Sugar

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pre-diabetes

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insulin

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Diabetes Type 2

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fpg



About 24 million Americans, or 8 percent of the U.S. population, have diabetes. Although people with diabetes are at risk for serious medical complications, with close monitoring and treatment they need not suffer from them. The problem is 1 in 4 people with diabetes don’t even know it.

Compared to many other diseases, diabetes can be diagnosed easily. In people without any symptoms of the illness, two routine blood tests can provide the diagnosis. The first is to screen for the disease; if abnormal, the test is repeated. The most commonly used screening test for diabetes is a fasting plasma glucose test, or FPG. Because diabetes is characterized by abnormally high sugar levels in the blood (also called plasma), an FPG of 126 mg/dl or higher is suggestive of the condition.

While this sounds simple enough, diagnosing diabetes can be more challenging in practice. The problem with FPG is that it requires not eating anything for at least 8 hours prior, which is typically done by having the patient return on another day after skipping breakfast. This creates at least two barriers. First, for many patients coming to the doctor is an ordeal. My patients often have to take time off of work to see me. This is particularly true for those with blue-collar jobs that require them to report to work early in the morning, the exact time that the blood sample must be drawn. The second barrier is that returning for labs makes follow up more difficult. It is easier for doctors to keep track of tests that are done in the same office visit than those done later. As I discussed in a previous entry (http://beyondapples.org/2009/07/30/forgetting-to-break-bad-news/), studies show that over seven percent of clinically significant abnormal test results are not reported back to patients.

New recommendations from the American Diabetes Association (ADA) support the use of a new screening test, hemoglobin A1c (HbA1c), that promises to make the process easier.(1) HbA1c avoids the pitfalls above because it does not require an overnight fast. Blood glucose levels change moment-to-moment with food, stress, and time of day; in contrast, HbA1c is a measure of a person’s average blood sugar levels over the previous two to three months. As a “running average,” it is less subject to daily variation and is already being used to monitor people with diabetes. An HbA1c of 6.5% or higher is suggestive of diabetes.

Another advantage of HbA1c is that it allows doctors to more reliably diagnose diabetes in hospitalized patients. Any illness creates a sympathetic “fight-or-flight” response that drives up heart rate, blood pressure, and, it turns out, glucose levels. As a result, a patient who has an elevated FPG in the hospital may have diabetes or just be hyperstimulated. With HbA1c, doctors will be able to detect diabetes in those who are often at greatest risk of having it — those who slip through the cracks of good primary care and wind up in the hospital.    

So should you be screened for diabetes? The United States Preventive Services Task Force (USPSTF) recommends routine screening for diabetes in individuals with a blood pressure above 135/80 mmHg.
(2) The ADA casts a wider net and recommends screening in all adults ages 45 and older, and younger adults who are overweight (body mass index or BMI > 25kg/m2) and have any additional risk factors:  

    * physical inactivity
    * first-degree relative with diabetes (parents, siblings, children)
    * members of a high-risk ethnic population (e.g., African American, Latino, Native American, Asian American, Pacific Islander)
    * women who delivered a baby weighing > 9 lbs or were diagnosed with gestational diabetes
    * hypertension (> 140/90 mmHg or on therapy for hypertension)
    * HDL cholesterol level  250 mg/dl
    * women with polycystic ovary syndrome
    * other clinical conditions associated with insulin resistance (e.g., severe obesity, acanthosis nigricans)
    * history of cardiovascular disease

To calculate your BMI, go to http://www.nhlbisupport.com/bmi/.

Like FPG, HbA1c can also help identify individuals with pre-diabetes, those with sugar levels that are abnormal but not enough to diagnose diabetes. For FGP, individuals with a blood sugar level of 100-125 mg/dl have pre-diabetes; with HbA1c the range is 5.7%-6.4%. One-third of people with pre-diabetes will develop diabetes within 3 years; recognizing the condition is critical because studies show that through aggressive lifestyle modifications people with pre-diabetes can prevent the onset of diabetes (see http://beyondapples.org/2009/11/14/world-diabetes-day-2009/).

Why go through all this trouble to talk about a new test for diabetes? After all, isn’t your doctor the one who decides whether to order blood work and what tests to order? The trouble is that we’ve learned the hard way that it takes anywhere from 7 to 10 years for the medical community to adopt a new guideline. For those of us at risk for diabetes that’s not soon enough. The next time your doctor orders blood work ask him or her about getting screened for diabetes. If you don’t need fasting blood work for another reason and are worried about having to come back, ask about HbA1c.

- Shantanu Nundy, M.D.


(1) Standards of Medical Care in Diabetes — 2010. American Diabetes Association. Diabetes Care, Volume 33, Supplement 1, January 2010.

(2) http://www.ahrq.gov/clinic/uspstf08/type2/type2summ.htm