Saturday, November 1, 2014

The Nutrition Debate #258: “Diagnosed diabetics consumed less sugar and carbohydrates…”

The stuff I read in the morning gets my blood boiling sometimes…but then, it is blog fodder after all. The headline in the Medscape Medical News article read, “Diabetes Diagnosis Changes People’s Eating Habits.” Really? I had to check this out. The story then asserts, “Diagnosed diabetics consumed less sugar and carbohydrates and more protein than their undiagnosed peers, researchers reported online September 9 in Diabetes Care.” So, off to check the source material.

My finding: This result was entirely self-reported (by “24-hour dietary recall” method) from among 3725 adults with diagnosed and undiagnosed diabetes or prediabetes who were in a morning fasting group in the 2005-2010 National Health and Nutrition Examinations Survey (NHNES). The diagnosed individuals with diabetes and prediabetes “received a 60-minute session on medical nutrition.” The CDC’s CONCLUSION: “Screening and subsequent knowledge of glycemic status may favorably affect some dietary patterns for people with diabetes.” That’s hardly “conclusive,” but not unreasonable.

What the diagnosed diabetics and prediabetics (who were the only ones who received the “medical nutrition” counseling) said they ate in the self-reported survey became “…may favorably affect some dietary patterns” in the study, and morphed into “Diabetes Diagnosis Changes People’s Eating Habits” in the Medscape headline.

“No significant differences in macronutrient intake were found by awareness of prediabetes,” the study concluded. Of course, they meant “self-reported,” not “found,” but the takeaway holds. The medical journalist gets a story, a headline (and a job), and the “researchers” still get paid to do a worthless, wishy-washy study that concludes “may favorably affect some dietary patterns…” (emphasis added by me) and no doubt calls for further studies (more job security for them too).

The headline gives false comfort to practitioners who conclude that counseling patients to eat a “good diet” – that is “healthy foods” as defined by the government’s Dietary Guidelines – will result in improved health and the avoidance of a diagnosis of prediabetes or diabetes. I wish that it were so! In this study, the diagnosed men consumed fewer carbohydrates (235g vs. 262g) and more protein (92g vs. 90g) than undiagnosed men.” That was the effect of the nutritional counseling based on the government’s guidelines. Diagnosed diabetics eating 235g of carbohydrate a day!!! Remember a normal blood sugar level is about 5 grams.  (

In a separate study published online September 11 in the Journal of the Academy of Nutrition and Dietetics (formerly the American Dietetic Association), “shows the importance of nutritional counseling and healthy diets for prediabetics, too.” This research was a “randomized trial” (RCT), a higher quality study. The RESULT: “People with prediabetes who received a 60-minute session of medical nutrition counseling had significantly lower HbA1c levels 12 weeks later, compared to a usual care group.” Now, those results bear further examination. Let’s do it. Medscape reported,

“The study involved 76 prediabetic patients with impaired fasting glucose or an HbA1c of 5.7% to 6.4%. The mean values for HbA1c were similar at baseline: 5.99% in the intervention group and 5.95% in the control group. After 12 weeks, however, the mean HbA1c in the nutrition therapy group was 5.79%, compared to 6.4% in the usual care group.”

So, the mean A1c among those who received “nutritional counseling” decreased from 5.99% to 5.79%, a reduction of 0.20%, or just over 3%, while the mean A1c in the control group, who received no nutritional counseling, increased from 5.95% to 6.4%, an increase of 0.45% or 7.5%. I’m guessing this RCT was not “blind,” and that the control group went off on a 12-week Bacchanalian feast. Another take on the numbers is that both groups remained prediabetic (A1cs 5.7%-6.4%), while the intervention group edged closer to “normal” and the control group progressed rapidly toward becoming full-blown diabetics. That’s what can happen (in just 12 weeks) while raiding the cookie jar in the name of science.

The results, of course, could have been much more definitive and “conclusive” had the intervention group been counseled to eat a different "healthy diet." As it is, “patients in the intervention group has been encouraged to follow diets that were calorie-restricted and balanced, so that 60-70% of the energy came from carbohydrates and monounsaturated fats, 15-20% from protein, and less than 7% from saturated fat” (my emphasis). Boy, the “dietary guidelines” target keeps changing.

Have you even seen the macronutrient percentages for “carbohydrates and monounsaturated fats” combined? I haven’t. On this topic, my editor recently wrote, “I think they are trying to creep up on: “fat ‘okay,’ sugar ‘bad’ in a roundabout way to obscure previous errors.” She’s right, of course. And notice also that the percentages don’t add up to 100% and that the missing fats are PUFAs, the polyunsaturated fats in the vegetable and seed oils that the USDA pushed and now dominate our processed food supply. Polyunsaturated fats are increasingly implicated in inflammation and poor health outcomes.

The problem with this whole line of public health advocacy is epitomized in the 1st comment on the Medscape piece: In a contrarian vein, the commenter says, “However, I can tell you that a prediabetic diagnosis is discouraging for someone who has exercised regularly for years, has maintained a good diet, and isn’t overweight.” I am empathetic and can only add that had the she followed a different "healthy diet," her outcome (and so many others) could be very different. If you want to avoid the risk of developing a broken glucose metabolism, try eating a lot fewer carbohydrates.

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