Clearing Up the Carb Confusion
The continuing popularity of low-carb diets over the years has resulted in many people greatly restricting carb foods. Yet studies looking at the healthiest, longest-living people in the world show a dietary pattern high in healthy, quality carbs, with a low intake of disease-promoting processed carbs.
The Full Plate Approach recommends the majority of your daily carbs come from whole, unprocessed fiber foods – also known as high-quality carbohydrates because these foods are associated with greater health.
In this article, we’ll walk you through the ins and outs of carbohydrates and help clear up the carb confusion by addressing the following:
- What are carbohydrates and why are they important?
- The quality of your carbohydrates – That’s what it’s all about!
- The Full Plate Approach and Carbs
- What about low-carb diets like Keto?
Read on :).
What are carbohydrates and why are they important?
Carbohydrates are one of the three main categories of nutrients. Except for fiber, our digestive system breaks down carbohydrates into glucose, which is also known as blood sugar. The glucose is absorbed into the bloodstream and carried to all the cells of the body to provide energy for all the countless tasks they perform. It’s essential for life. We have to have a certain amount in our bloodstream at all times in order to live.
In short, carbohydrates provide our body with the energy necessary for life!
There are three kinds of carbohydrates: sugars, starches and fibers. Lets go deeper into what each of these are:
#1 Sugars are easily and rapidly digested because of their simple structure, meaning glucose enters the bloodstream quickly. This can result in a faster rise in blood sugar levels, often referred to as a blood sugar spike. It’s these blood sugar spikes which have negative health effects over time, increasing inflammation and risk of type 2 diabetes, heart disease and obesity.(1)
#2 Starches take longer to break down into glucose because of their complex structure, causing the blood sugar to rise more slowly. In contrast to sugars, starches have less of an immediate impact on blood sugar levels.
#3 Fibers are the one category of carbohydrates that we can not digest. That means fiber is not broken down into glucose, does not provide energy for the body and does not raise blood sugar levels.
However, fiber performs many important functions. As it passes through the digestive system it helps slow down the digestion and absorption of food, provides satisfaction and fullness after eating, promotes regularity, and when it moves into the large intestine, it is fermented by good gut bacteria, which improves the gut microbiome.
The quality of your carbohydrates – That’s what it’s all about!
Not all carbohydrate foods are created equal in terms of their immediate effects on blood sugar and their association with risk of disease.
While we often focus on the amount of carbohydrates we’re eating, evidence has shown the quality of carbohydrate foods is more important. It’s the quality of the carbs we are consistently eating that has the strongest impact on how healthy we are.(2-4)
High-Quality Carbohydrate Foods
Overwhelming evidence has shown that the best kind of carbohydrate foods for health and longevity are whole, unprocessed foods in which all three kinds of carbohydrates (sugars, starches and fibers) are naturally present together, not separated from one another. These foods also contain an outstanding array of vitamins, minerals, antioxidants and phytochemicals we need to stay healthy. That is why researchers like to call them high-quality carbohydrate foods.
Fiber is the Key
Fiber plays a big role in carbohydrate quality. It's the fiber in whole fiber foods that helps regulate carbohydrate digestion.
Since fiber is not broken down during digestion and absorbs water as it moves through the digestive tract, it functions like a net, slowing down the digestion and absorption of glucose from the meal. This helps avoid the blood sugar roller coaster of highs and lows after eating, which can be a problem for anyone. When your blood sugar drops precipitously, you won’t think as fast, you may make more mistakes, feel shaky, nervous and tired. When it’s too high, it increases risk of heart and kidney disease, stroke, vision loss and other long term problems.
When we eat carbohydrate foods which naturally contain fiber, the overall effect is lower blood sugar levels that are easier for the body to keep within the normal range.
High-Quality Carbohydrates are only found in fruits, vegetables, beans and legumes, whole grains, nuts and seeds in their whole form.
There is another category of carbohydrate foods commonly called processed or refined carbs. These foods and beverages are considered low-quality carbs because all three kinds of carbohydrates (sugars, starches and fibers) are not naturally present together. One or two of them are missing or have been added by food manufacturers. Besides loss of all or most of the fiber, processing also results in large losses of various vitamins, minerals, antioxidants and phytochemicals. Risk of disease increases when these kinds of carbohydrates dominate the diet. It commonly shows up in your yearly labs - higher fasting glucose, HbA1c levels and triglycerides.
Low-quality carbohydrates are found in foods like baked goods, white rice, cereals, white and brown sugar, syrups, candy, cookies, pastries, juice, sugar-sweetened beverages and alcohol.
The Full Plate Approach and Carbs
The Full Plate Approach recommends the majority of your daily carbs come from whole, unprocessed fiber foods – those high-quality carbohydrates. We call these foods 75% plate foods because the goal is to fill 75% of your plate at every meal with some combination of fruits, veggies, beans and cooked whole grains. When you do this from meal to meal, day after day, you will be enjoying a good, quality high-fiber diet, which has been shown to be associated with health, longevity and decreased risk of many common diseases.(4-6)
Yes, we are all going to eat low-quality carbs at one time or another. The Full Plate Approach reserves a small (25%) portion of your plate for you to enjoy foods that are not considered a high-quality carb. For better health, we recommend you choose healthier 25% foods the majority of the time.
What about low-carb diets like Keto?
The basic assumption behind low-carb diets, such as the popular Keto diet, is that all processed, low-quality carbs in the typical American diet are the culprits behind our epidemics of obesity and type 2 diabetes. Since carbs raise blood sugar and insulin levels, these diets claim that most carbs need to be eliminated and replaced with fat and protein, the majority from animal sources. This results in a high saturated fat, low-fiber diet. The primary focus is on the quantity of carbohydrates eaten rather than the quality, and an assumption is often made that all carbohydrates behave the same in the body.
Whether you are overweight, have types 2 diabetes or neither, the best available scientific evidence has failed to show the benefits of low-carb diets on long term weight loss and fat loss, both essential for turning around type 2 diabetes. The best available scientific evidence has also failed to show that all carbohydrate foods have the same effects on the body.(2,3,7)
There is evidence that a high saturated fat diet is the major cause of insulin resistance (8-12), which is the underlying cause of type 2 diabetes. So replacing carbs with animal fat and protein high in saturated fat is not a long-term solution for optimizing blood sugars.
In addition, high saturated fat intake causes high LDL cholesterol levels, the direct cause of coronary heart disease, which is the leading cause of death in men and women with and without type 2 diabetes. That is why the American Heart Association recommends saturated fat intake be limited to no more than 6% of total daily calories.
While low-carb and Keto diets have been used for short-term treatment in some patients, they should be prescribed and monitored by your doctor or an appropriate healthcare professional. It would be prudent to have a plan in place for moving to a more sustainable, healthy way of eating.
In order to optimize your health, choose mostly high-quality carbohydrate foods. When you do choose to eat low-quality carbs, do so infrequently in small amounts. Unless under the direction and supervision of your doctor, stay away from low-carb diets, like Keto, that can have long-term negative effects on your health.
To start taking steps to enjoy more high-quality carbs for better health, use the Full Plate Approach.
This will help protect the most precious possession you have--your health!
Augustin LSA, Kendall CWC, Jenkins DJA, Willett WC, Astrup A, Barclay AW, Björck I, Brand-Miller JC, Brighenti F, Buyken AE, Ceriello A, La Vecchia C, Livesey G, Liu S, Riccardi G, Rizkalla SW, Sievenpiper JL, Trichopoulou A, Wolever TMS, Baer-Sinnott S, Poli A. Glycemic index, glycemic load and glycemic response: An International Scientific Consensus Summit from the International Carbohydrate Quality Consortium (ICQC). Nutr Metab Cardiovasc Dis. 2015 Sep;25(9):795-815. doi: 10.1016/j.numecd.2015.05.005. Epub 2015 May 16. PMID: 26160327.
Sievenpiper JL. Low-carbohydrate diets and cardiometabolic health: the importance of carbohydrate quality over quantity. Nutr Rev. 2020 Aug 1;78(Suppl 1):69-77. doi: 10.1093/nutrit/nuz082. PMID: 32728757; PMCID: PMC7390653.
Reynolds A, Mann J, Cummings J, Winter N, Mete E, Te Morenga L. Carbohydrate quality and human health: a series of systematic reviews and meta-analyses. Lancet. 2019 Feb 2;393(10170):434-445. doi: 10.1016/S0140-6736(18)31809-9. Epub 2019 Jan 10. Erratum in: Lancet. 2019 Feb 2;393(10170):406. PMID: 30638909.
Veronese N, Solmi M, Caruso MG, Giannelli G, Osella AR, Evangelou E, Maggi S, Fontana L, Stubbs B, Tzoulaki I. Dietary fiber and health outcomes: an umbrella review of systematic reviews and meta-analyses. Am J Clin Nutr. 2018 Mar 1;107(3):436-444. doi: 10.1093/ajcn/nqx082. PMID: 29566200.
Barber TM, Kabisch S, Pfeiffer AFH, Weickert MO. The Health Benefits of Dietary Fibre. Nutrients. 2020;12(10):3209. Published 2020 Oct 21. doi:10.3390/nu12103209
Naude CE, Brand A, Schoonees A, Nguyen KA, Chaplin M, Volmink J. Low-carbohydrate versus balanced-carbohydrate diets for reducing weight and cardiovascular risk. Cochrane Database Syst Rev. 2022 Jan 28;1(1):CD013334. doi: 10.1002/14651858.CD013334.pub2. PMID: 35088407; PMCID: PMC8795871.
Taylor R. Pathogenesis of type 2 diabetes: tracing the reverse route from cure to cause. Diabetologia. 2008 Oct;51(10):1781-9. doi: 10.1007/s00125-008-1116-7. Epub 2008 Aug 26. PMID: 18726585.
Xiao C, Giacca A, Carpentier A, Lewis GF. Differential effects of monounsaturated, polyunsaturated and saturated fat ingestion on glucose-stimulated insulin secretion, sensitivity and clearance in overweight and obese, non-diabetic humans. Diabetologia. 2006 Jun;49(6):1371-9. doi: 10.1007/s00125-006-0211-x. Epub 2006 Apr 5. PMID: 16596361.
Parker DR, Weiss ST, Troisi R, Cassano PA, Vokonas PS, Landsberg L. Relationship of dietary saturated fatty acids and body habitus to serum insulin concentrations: the Normative Aging Study. Am J Clin Nutr. 1993 Aug;58(2):129-36. doi: 10.1093/ajcn/58.2.129. PMID: 8338037.
Maron DJ, Fair JM, Haskell WL. Saturated fat intake and insulin resistance in men with coronary artery disease. The Stanford Coronary Risk Intervention Project Investigators and Staff. Circulation. 1991 Nov;84(5):2020-7. doi: 10.1161/01.cir.84.5.2020. PMID: 1934376.
Wang L, Folsom AR, Zheng ZJ, Pankow JS, Eckfeldt JH; ARIC Study Investigators. Plasma fatty acid composition and incidence of diabetes in middle-aged adults: the Atherosclerosis Risk in Communities (ARIC) Study. Am J Clin Nutr. 2003 Jul;78(1):91-8. doi: 10.1093/ajcn/78.1.91. PMID: 12816776.
Full Plate Living is a small-step approach with big health outcomes. It's provided as a free service of Ardmore Institute of Health.