Throw Out the Carb & GI Books?

Melinda Seed writes for Twice Diabetes
Melinda Seed writes for Twice Diabetes

Every day 100s of pieces of diabetes-related research are published and disseminated through cyberspace. In most cases they vary from the ludicrously irrelevant to mildly interesting but in very rare circumstances there is something potentially revolutionary. I just read a study that falls into the latter category for diabetes management.

A recently published study* of 800 non-diabetic people fitted with CGM found that

Surprisingly, the foods that raise blood sugar levels differ dramatically from person to person.”

“…the scientists found that different people responded very differently to both simple and complex meals. For example, a large number of the participants’ blood sugar levels rose sharply after they consumed a standardized glucose meal, but in many others, blood glucose levels rose sharply after they ate white bread, but not after glucose. “

So this study shows that the science we’ve been taught about carb counting and the GI factor does not hold true in individuals.  Let that sink in for a moment. Those handy books with their carb count and GI factor and those alogorithms based on averages….they don’t work. We have been taught that white bread has a GI factor very similar to glucose and yet here are many people with very different response to glucose than white bread.

One woman had huge spikes from eating tomatoes.  I’m almost certain that if a diabetic took a food diary and bsl record/CGM output to a health care professional that showed highs after eating tomatoes, the HCP would think she was a “non-compliant liar”.  Why wouldn’t they when everyone “knows” tomatoes are low-carb and low GI?

But truly I only ate 1 raw tomato!
But I only ate 1 raw tomato!

What’s particularly exciting about the study is that the researchers were able to do a follow-up study in which they designed personalised “good” and “bad” diets for participants . These diets obviously varied for each person but the good diets kept sugars stable while the “bad” diets showed spikes.  What’s even more exciting from a diabetes perspective is that the researchers were able to use the data from individuals to predict their personalised bsl response.

This is huge! You’d think the endos, the DEs, the dietitians and Diabetes organisations like ADA, IDF (who are telling us all to eat a healthy diet) would be abuzz. If this study can be replicated and holds true for people with diabetes (either type 1 and/or type 2) this would revolutionise diabetes education. Standardised advice and algorithms cannot be relied upon.  Studies that show average results for groups of people can’t be applied to individuals.  This is particularly heartening to me, who tried to follow a low-carb diet only to find that it made me insulin resistant.  I suspect that I might have inherited the genes of my ancestors who thrived on a diet consisting almost entirely of potatoes, so I am genetically programmed for carbs. So a study that shows that the average reduction in insulin needs for a group on LCHF is greater than those on a moderate carb, low fat diet does NOT mean that a LCHF diet is best for everyone in achieving a reduction in insulin needs.

So my questions for the 1000s of HCPs working in diabetes, the 1000s of researchers, the professional associations of dietitians, Endos, DEs and the diabetes organisations like American Diabetes Association and Diabetes Australia who bang on ad nauseum about “diet”

*Who is going to fund the replication of this study in people with diabetes?

*Pending the urgent resolution of whether this information holds true in people with diabetes, when will you amend your diet advice?

*Dietitians and DEs, will you amend your practice to gather the data necessary for each individual and then devise a personalised diet for each person rather than the standard dissemination of information.

*Diabetes organisations will you lobby and advocate for the resources necessary to gather the data and create individualised diets for optimising blood sugar stability?

Will this study just fade into oblivion whilst people continue to be handed generalised dietary information that is potentially harmful and certainly won’t achieve optimal control of diabetes?

*The quotes are from the above linked Science Daily Journal, the original article is available here: Personalized Nutrition by Prediction of Glycemic ResponsesCell, 2015; 163 (5): 1079 DOI: 10.1016/j.cell.2015.11.001


4 thoughts on “Throw Out the Carb & GI Books?

  1. This is what I’ve been saying for years. Doesn’t every Diabetic find out for themselves what food raises the BSLs and what foods they can “get away with”? Every Diabetic individualizes their diet. So many times I have been disbelieved and labelled non-compliant just as the above post says, even to the point of being put in hospital and given a controlled diet for observation. Left many Drs shaking their heads with no answers. Which raises the point about hospital menus. I have heard time after time and experienced it myself hospital’s diabetic diets which consist of “assorted diabetic sandwiches”. How low carb is that? I believe diabetics in hospitals should be able to choose freely from the menu. We know what we can and can’t eat to suit ourselves. As I’ve been T1 for almost 50 years I have seen it all from carbs 6 times a day to the current low carb, high fat trend which to me is just another fad which will change in a couple of years and be a big “no no”. And I agree this study will fade into oblivion. P.S. I love my tomatoes and they don’t raise my levels. P.P.S. I had a treat last weekend (very rare for me to stray from the straight and narrow of what I know I can eat). Two large oven-baked spring rolls. I hypoed at 1.4 in the early hours of the morning. Still need to do some work on that one.

  2. This sort of thing reminds me of Martin Seligman’s experiments in Learned Helplessness. I think, just my opinion though, that being told that your body should react one way, yet you find it doesn’t wears people down, discourages and frustrates them.

    So why is there a culture of this? I think I has to do with people trying to be helpful. However, if they are not experiencing it themselves, I think it makes it easy to ignore contradictory evidence from patients/clients and put it down to patient perhaps being ‘non-compliant’.

    I think patients and health-care givers alike want to feel in control of what happens to them, it is human nature. I personally just use their recommendations as a guide. I rely on the what my meter tells me, factoring all the other variables (that I can think of). My own experience of this has been being told by a dietician that oats are a great breakfast – they are slow to digest. My blood sugar meter disagrees with this.

  3. Wow Thanks Mel – excellent observation and one that I can totally relate to as well. A recent Doco I watched spoke of 2 people from the same country (India) and now living in New York driving taxis, both with sedentary lifestyles and eating high calorific processed diets. One of them, however, came from a village where his mother ate grains and unprocessed food whilst pregnant, and the other came from a big urbanised city where the mother ate highly processed, high calorific foods whilst pregnant. The one from the small village developed Type 2 diabetes, but the other continued with the highly processed diet and did not get Type 2 diabetes. It was suggested in this doco that the man who did not get T2D had genes that had become programmed to accept this high calorific highly processed diet whilst in the womb, but the other mans genes had not. Interesting. Anyway, in my personal experience with T1D, and carb counting, that different foods and different times of the day , week, or month had an inconsistent impact on my BSLs. And that depending on how much energy I had expended prior to eating, that my BSL after eating, would be different every time, even if I had that exact same amount of carb.It all depended on whether I was dropping before my BSL or going up before my BSL test! Totally inconsistent.Thanks for sharing that article – I do hope that the study will be funded for further study to be conducted on T1Ds very soon! Here’s hoping!

Leave a Reply to LMC Cancel reply