The Unintended Consequences of a Singular Focus on Carbohydrates & The Clinical Translation of Carbohydrate Quality

    At his 2018 presentation at the 117th Abbott Nutrition Research Conference, Dr. John Sievenpiper discusses the findings from randomized controlled trials, systematic reviews, and meta-analyses on carbohydrate consumption. With current trends in nutrition focusing on carbohydrate consumption as a predominant cause of preventable disease, Dr. Sievenpiper brings to light these questions: Are carbs really the enemy? Or is it a matter of quality versus quantity? What should we tell our patients? 

    According to Dr. Sievenpiper, the singular focus on carbohydrates has led to three unintended consequences in regards to nutritional behaviors and thinking. The first being a revisiting of the low fat paradigm, now manifested as a fear of carbohydrates.1 The second being the demonization of fructose, and furthermore the avoidance of whole fruit. The third unintended consequence is that we have lost sight of the overall picture when considering all possible threats to our health. By focusing solely on carbohydrates and particular sugars, as opposed to all the other possible exposures and risks, we miss the big picture. Which reinforces the question: should we really be focusing solely on carbs?

    A paradigm shift has occurred where sugar (and by extension, carbohydrates) has replaced fat as the dominant public health concern of today. The low-fat paradigm which started in the 1980s and lasted nearly three decades dubbed “low fat” as the buzzword and ideal of health among the media, the public, and the nutrition community. Fueled by consumer desires, products claiming to be “low fat” flooded the shelves as the public then equated foods high in fats as being responsible for obesity and preventable disease. However, as Dr. Sievenpiper put it, “low fat does not equal low calorie.” For many products claiming to be low in fat, the addition of refined carbs (namely sugars) substituted what fats were removed. People then--under the guise that low-fat equates healthy--consumed higher amounts of these products to the detriment of their health. With the paradigm shifting to sugars and carbs as the enemy, we are almost reverting back to the eating habits we had prior to the low-fat paradigm. The media tells us to eat fats, consume butter, and glamorizes diets like the ketogenic diet irregardless of the patient’s unique needs. This has led to the idea that carbs (irrespective of type) are now the enemy, and so comes an influx of low-carb products where yet again the carbohydrates removed are replaced by other ingredients, fueling overconsumption once more. 

    With this paradigm shift comes the second unintended consequence: the avoidance of fructose (and in extension, whole fruit). Publications like “A Diet Manifesto: Drop the Apple and Walk Away”, promulgated the idea that fructose sugars (including that found in whole fruits) could lead to the production of fat. This consequence relates to the question of does food source matter? Findings from diabetes data meta-analyses show that there is actually no adverse association of sugars as whole, but rather a protective association of fructose. So, yes, form does matter. To explain, sugar sweetened beverages show a consistent adverse signal across studies in regards to diabetes, heart disease, and cardiovascular mortality. However, it has been found that in these same studies there are protective signals for whole fruit, whole grain breakfast cereals, and other surprising carb sources such as chocolate. Sugar sweetened beverages is the one signal that shows recurrent adverse effects. Whole fruits do not. 

    The last unintended consequence is that we are losing sight of the overall picture. Dr. Sievenpiper poses the question, “Of all the exposures, are carbs and particular sugars all that important?” When ranking foods among the 79 risk factors attributable to the global burden of disease, low consumption of whole grains shows the highest amount of DALYs, which is followed in descending order by fruit and fiber. Ranking 14th are sugar sweetened beverages. What does this mean? This means that carbohydrate quality is indeed important. 

    So, how does this all translate to clinical practice? Sievenpiper says that, “There is no one-passed diet. [The] important thing is getting it passed the mouth. [And it is] incumbent on the clinician to align diet with values and treatment goals of patients.” By focusing solely on one nutrient, we miss so much of the bigger picture in our attempt to aid our patients and effect positive change in their health. The most important determinant for success in any diet is adherence. With that, one must consider a variety of factors such as values, preferences, high food costs, allergies, gastrointestinal (GI) side effects, as well as culinary, cultural, and ecological/environmental considerations that may become barriers to adherence.  

References 

Sievenpiper J. Carbohydrate Quality: What Do I Tell My Patients?. Presentation presented at the: 2018; 117th Abbott Nutrition Research Conference.