Understanding Blood Sugar

The intake of dietary sugar has increased significantly over the past few hundred years. If you would like a detailed history of sugar, I would suggest reading The Case Against Sugar by Gary Taubes. In this book, he chronicles how human beings dramatically increased their sugar intake over the past few hundred years and how this increase likely came along with a host of diseases, such as diabetes, that were once a very rare malady. The goal of this post is to explain the effect sugar has on the human body, and why it may be beneficial to limit your sugar and carbohydrate intake.

You are likely consuming sugar everyday in one form or another. When I say “sugar,” I do not necessarily mean the white, powdery sugar you use to sweeten your coffee in the morning. Every carbohydrate you consume, whether it comes from bread, pasta, or fruit is converted into a type of sugar in the body known as glucose. Imagine you eat a bowl of cereal in the morning for breakfast; let’s say it was a “heart healthy” (dramatic air-quotes were used there) cereal such as cheerios. If you look at the nutrition label, there’s only 1 gram of sugar per serving in Cheerios. Fantastic! It has a low sugar content so that means it’s good for me. Not so fast! A closer look will reveal 20 grams of carbohydrates per serving. These carbohydrates will cause your blood sugar to spike and your body to release insulin.

Your blood sugar spiking and insulin levels rising are totally normal physiologic functions. A healthy human being should be able to handle blood sugar spikes without a problem. Our bodies are good at keeping us at a baseline in various ways; this process is commonly known as homeostasis. Not only does the body regulate blood sugar, but it also regulates your body temperature, pH, fluid balance, and ion concentrations.  Our bodies are resilient, but there is a limit for how long it can compensate before something goes awry. In the case of sugar, you can develop insulin resistance.

The pancreas is the gland which secretes insulin when its blood sugar concentrations rise. Insulin is a hormone that signals cells to absorb sugar from the blood. When the body is overloaded with sugar, it can become insulin-resistant which can lead to full blown diabetes.  Cells no longer respond to insulin’s signals, thereby leaving sugar in the blood. This is known as insulin resistance which can progress to type 2 diabetes.  According to the CDC, 30 million Americans have diabetes including cases that haven’t been diagnosed. Furthermore, 33% of US adults have prediabetes or insulin resistance. These statistics are scary to say the least, and the economic burden this places on our country is not sustainable. But let’s get back to your own body’s physiologic function because we can’t fix the country’s problems without fixing ourselves first.

Not all carbohydrates are created equally. Certain carbohydrates, such as the ones in soda, are processed and utilized very quickly while others, such as vegetables, are processed more slowly. The glycemic index is a tool that can be utilized to find out which carbohydrates give you a quick boost of energy and which ones give you a longer sustained amount of energy. https://www.health.harvard.edu/diseases-and-conditions/glycemic-index-and-glycemic-load-for-100-foods

While there exists some controversy concerning the index’s accuracy, it can, nevertheless, guide you in determining how certain foods will affect your blood sugar. Ideally, you choose the carbohydrates that lead to a slower blood sugar rise.

Most people are unaware of how food really affects them. The initial pleasure of tasting a delicious treat and stimulation of the brain’s reward centers are perceived as an endpoint for how much people think about how food affects them. When I first start with a health coaching client, I ask the individual to fill out a food log that goes beyond a mere grocery list.  In addition to listing the foods, I have the client report emotional and physiologic symptoms they feel. For example, perhaps you experience the 3 pm naptime urge while you’re at work; perhaps you don’t realize the lunch you ate spiked your blood sugar, and the 3pm lull is your blood sugar dipping.  Within the context of homeostasis, your body will look to increase your blood sugar levels, and you may crave a sugary snack to get you through the rest of the day. By altering your breakfast and lunch choices, you can better stabilize your blood sugar and prevent the 3 pm lull from happening in the first place.

Everyone’s response to carbohydrate intake is unique. You might have great ability to stabilize your blood sugar. Others might have a harder time keeping blood sugar levels stable and experience greater changes in their energy levels. I would encourage you to experiment with choosing lower glycemic carbohydrates or even limit carbohydrate intake to vegetables and see if you notice any positive changes.

Below are some sources for nutrition information

SugarScience. The University of California, San Francisco. http://sugarscience.ucsf.edu/

CDC’s Diabetes Webpage. https://www.cdc.gov/diabetes/data/index.html

Harvard T. H. Chan School of Public Health’s Department of Nutrition, The Nutrition Source. https://www.hsph.harvard.edu/nutritionsource/

Chris Kresser’s Diabesity Series. https://chriskresser.com/diabesity/