How to Balance Blood Sugar on a Low-Carb Diet

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Low-carb diets are all about balancing blood sugar (blood glucose) levels. Beyond weight loss, we eat low-carb diets to keep our blood sugar normal and stable. To fully understand the connection, it's helpful to first familiarize yourself with how the body processes blood sugar in a normal state and even explore how that changes if someone has diabetes.

What Carbohydrates Have to Do With Blood Sugar

Carbohydrates have everything to with blood glucose. All foods with carbohydrate — whether rice, jelly beans, or watermelon — break down to simple sugars in our bodies turning into glucose through metabolic processes. This process is what causes our blood glucose to rise.

The carbohydrate in most starchy foods (potatoes, bread) is simply a collection of long chains of glucose, which break down quickly and raise blood sugar. 

What Our Bodies Do When Blood Sugar Is High

When our blood sugar goes up, our body responds by secreting insulin to stabilize it. The sugar is then taken out of the blood and converted into fat; insulin's primary function is facilitating the storage of extra sugar in the blood as fat. People with diabetes are unable to balance blood sugar when the process of converting food to energy takes place.

When sugar levels are high, the ability of cells in the pancreas to make insulin goes down. The pancreas overcompensates for this lack of insulin and insulin levels stay high, as does blood sugar. Over time, the pancreas is permanently damaged and other bodily functions are affected such as hardened blood vessels, among other ailments.​

Problems With Blood Sugar Going Up

However, for many people, this metabolic process works fine. Sometimes, though, people reach a point in their lives when it goes awry (or it doesn't work well from childhood). This is called insulin resistance, and one of the consequences is that there gets to be too much insulin in the blood as the body tries harder and harder to bring the sugar down.

When insulin is high, weight gain is more likely, since a main function of insulin is fat storage. Conversely, people with high insulin levels are more likely to lose weight on low-carb diets.

Keeping blood glucose normal has other health benefits, such as the prevention of heart disease and diabetes. Even people who do not have diabetes have an increased heart disease risk with higher blood glucose levels.

What About the Glycemic Index? 

The glycemic response of the body to a carbohydrate is important. Although the glycemic index has its limitations as a tool, it can give a rough idea of how your body may respond to a given food.

However, remember that serving size is also important. Eating a whole lot of a low-glycemic carbohydrate food will still raise your blood glucose. This is why many people find it's easier just to limit foods with a lot of carbohydrates by following a low-carb diet.

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Article Sources
  • Ebbeling, Cara, Leidig, Michael, Feldman, Henry, et al. Effects of a Low–Glycemic Load vs Low-Fat Diet in Obese Young Adults. Journal of the American Medical Association. 297.19 (2007):2092-2102.

  • Selwin, Elizabeth, Coresh, Joseph, et al. Glycemic Control and Coronary Heart Disease Risk in Persons With and Without Diabetes. Archives of Internal Medicine. 2005. 165/16.