Slow-Digesting Carbs and Blood Sugar Control

If you’re unsure about the type of carbs to eat on a blood sugar friendly diet you are not alone. Julia Zakrzewski, RD, helps us understand slow carbs and if they are a good choice to promote stable blood sugar.

Woman chopping cilantro and putting into a mason jar
Julia Zakrzewski, RD
— Signos
Health & Nutrition Writer
Green checkmark surrounded by green circle.

Updated by

Green checkmark surrounded by green circle.

Science-based and reviewed

July 24, 2024
May 2, 2022
— Updated:
September 20, 2023

Table of Contents

Slow-carb foods (also called slow-digesting carbs) function in the body exactly as they sound: they are digested slowly, which aids in keeping your glucose stable. These foods are high in fiber and break down over a longer period. From a glucose perspective, a slow breakdown of carbohydrate foods is always preferred.3

Why? The slow breakdown of carbohydrates results in a delayed impact on blood glucose. Slow changes within your bloodstream offer you a greater opportunity for tighter management of your glucose levels.

Another method of identifying slow carbs is to follow the glycemic index (GI). Low GI foods are considered slow-carb-release foods and should have minimal impact on your blood glucose.2 

To strengthen your efforts, pair low-GI foods with lean proteins and generous portions of vegetables. The protein and fiber will further delay the breakdown of food and promote a slow uptake of glucose into the blood.


What are Slow-Carb Foods?

  • Slow carbs digest slowly
  • Slow carbs are better for blood sugar control than simple carbs
  • Slow-carb foods are low-glycemic foods
  • Slow-release carbs are complex carbs

What is The Slow-Carb Diet? 

Author and self-proclaimed health influencer Timothy Ferris developed the slow-carb diet. He published the slow-carb diet in 2010, promoting a very restrictive diet with little to no processed foods or carbohydrates intake.

The dietary restrictions within the slow-carb diet are stringent and not supported by high-quality evidence or scientific research. The slow-carb diet suggests only eating animal protein, vegetables, fats, spices, and legumes. It promotes using supplements to satisfy any gaps in your nutrition while following the diet.

However, some broader recommendations within the slow-carb diet are suitable for daily life and the management of blood glucose. Choose nutrient-dense foods and complex carbs (slow-release carbs) over simple carbs to stay on top of your health goals.

Simple Carbs vs. Complex Carbs

A simple carb has a simple structure with one or two sugar molecules called monosaccharides and disaccharides.4 Simple carbs offer few nutritional benefits and are less favorable for blood sugar management. 

The simple sugars rapidly enter the bloodstream and increase the chances of blood glucose spikes.

Examples of Simple Carbs to Avoid 

  • White flour products (i.e., white bread)
  • Flavored yogurts
  • Fruit juices, sodas, specialty coffee beverages 
Simple Carbs to Avoid (Infographic): Flavored yogurt, white flour, sugary beverages

Examples of Complex Carbs to Eat

  • Whole-grain products (breakfast cereals, brown rice)
  • Legumes (lentils, kidney beans)
  • Fruits
  • Starchy vegetables (squash, sweet potatoes)

On the other end of the carbohydrate spectrum are complex carbs. These foods are rich in fiber, nutrients, and minerals, and the sugars are bound in long chains called polysaccharides.6 

The long chains take time to break down before they can be absorbed into the bloodstream. In your diet, prioritize complex carbs over simple ones because of the delayed effect on your blood glucose levels.

Complex Carbs to Eat (Infographic): Fruits, Whole Grains, Starchy Vegetables

How Do Slow-Carb Foods Affect Blood Sugar Levels?

Choosing slow-carb foods or foods with a low glycemic index will have a delayed impact on your blood glucose. These foods are also rich in fiber, minerals, and nutrients and promote stable blood sugars and health overall.

How Are Sugars Metabolized In The Body?

Whenever you eat a carbohydrate, your pancreas is signaled to release insulin hormones into your bloodstream. Insulin actively transports sugar molecules from your bloodstream and into its target destination.3 Any sugar that is not used for fuel will be stored for later use. 

As the sugar is cleared out of the bloodstream, insulin production wanes. If the sugar drops below your body’s ideal threshold, the liver will release glucagon to release stored sugars into your blood. 

The mechanism operates like a thermostat, activating when the number falls outside the desired range. Carbohydrates, insulin, and glucagon work together to ensure your blood levels remain stable and fuel is available for your muscles and brain.3

How Many Daily Carbs Should You Eat?

Every person will have unique carbohydrate requirements to maintain a stable blood sugar range.1 You and your health team should calculate your daily carbohydrate needs and spread them evenly throughout your meals.

Current estimates and guidelines for carb intake will be 45-50% of your daily caloric intake.2 That said, carbohydrates can affect people differently, so which carbs you consume matters as much as the total volume. Using a continuous glucose monitor (CGM) can help you discover which carbs you can eat without spiking your glucose.

What Are The Benefits Of Eating Slow-Carb Foods? 

There are many health benefits associated with eating foods on the slow-carb meal plan, including:

Aids weight loss efforts

Slow-carb foods are rich in fiber, essential vitamins, and minerals that support overall health. The high fiber content is vital to support mealtime satiety, which ensures you’re satisfied at meals and reduces the chances of overeating.

Stabilizes blood sugar levels

This eating pattern is full of foods high in fiber and protein but low in carbs and sugar. Evidence suggests this eating style can help normalize blood sugar levels, improve glycemic control, and decrease the risk of chronic diseases including insulin resistance, type 2 diabetes, and metabolic syndrome.8

Saves money and time

This eating style can be repetitive, easy to follow, and generally inexpensive compared to other diets. A slow-carb diet can also encourage you to eat at home more frequently and help you choose seasonal foods, often cheaper than fancy or hard-to-find ingredients.

What Are Good Slow-Carb Foods To Eat?

The slow-carb foods listed in the diet plan are limited to beans and pulses. 

Other great low-GI options include: 

  • Low-glycemic fresh fruits
  • Starchy vegetables such as sweet potato, squashes, and beets
  • Whole grains, including quinoa, steel-cut oats, barley, millet, and rye7 
  • All beans, legumes, and pulses  
  • Unflavored dairy products 

Despite best efforts, blood sugar spikes are bound to happen. Prioritize getting your blood sugar back in the normal range, then assess the events that led to that moment. 

Refined starches or refined white flour products typically impact your blood glucose most. Do not be afraid of these foods; instead, find a way to balance your meals or choose alternatives that better align with your blood sugar management plan but still keep you satisfied.

Slow-Carb Meal Planning Tips

Below are some practical tips to help you incorporate slow-carb meals into your daily routine.

Find a balance

Whether you decide to follow a low-carb, low-fat, or vegetarian diet, focus on incorporating nutrient-dense foods into your meals. Aim for a 50-25-25 split with the largest portion being non-starch vegetables (peppers, spinach), a section of protein, and one for grains and starches (beans, potatoes). Add in small servings of fruit, dairy, and healthy fats as you see fit.

Prioritize meal times

Skipping meals or going too long between eating can lead to low blood sugar levels and impulsive food choices. Block out time on your calendar for lunch and ensure you are starting the day with an energizing breakfast.

Use the glycemic index

If you are confused about what foods are considered slow carbs, check the glycemic index of the food item. The lower a good’s GI level, the slower it takes to digest. This also means your blood sugar levels will not spike and then crash suddenly. Low glycemic index foods include oatmeal, sweet potatoes, corn, carrots, various fruits, and non-starchy vegetables.

Increase fiber intake

Foods that are high in fiber take longer to digest, which means your blood sugar levels are impacted gradually. Fiber-filled foods include non-starchy vegetables like spinach or kale, citrus fruits, beans, and whole grains. Fiber can also help you feel fuller for longer periods of time, which aids in weight loss goals and increases overall satiety. 


Is Rice Allowed In The Slow-Carb Approach? 

White rice is considered a refined carbohydrate or a simple carbohydrate. Although rice is a cultural staple ingredient for people across the globe, a reduced intake of rice is recommended for optimized blood sugar control. 

If you love rice and can not imagine your meals without it, serve smaller portions. Add more vegetables and lean proteins to your rice to reduce the glycemic impact of the meal. 

Better yet, choose cooled brown rice, a resistant starch.

Is The Slow-Carb Diet The Same As A Low-Carb Diet? 

Not necessarily. Choosing slow carbohydrate foods does not mean cutting back on your carbohydrate intake. 

Instead, you are opting to be more selective with your carb choices. You may eat the same volume of carbs as you did before, but now you may be choosing to eat higher-quality carbs. 

Are Low-Carb Diets Good For Me? 

Low-carb diets may help you reach your goals faster, but the changes you make must be sustainable for long-term results.

Does The Slow Carb Diet Work With Signos? 

Slow or slow-release carbs can be safely included in your eating routine. Signos promotes nutrient-dense diets rich in unprocessed foods, fiber, and vitamins, usually low-glycemic foods. 

Choose whole grain and complex carbohydrate options whenever possible, and don’t forget to monitor your beverage choices, too! 

In the warmer months, cocktails, beer, frozen slushies, and pops become more popular as people hit the patio. Liquid sources of sugar, like beverages, can rapidly shoot into your bloodstream, making it more difficult to manage your blood sugar.

Are Slow Carbs Good for People Living with Type 2 Diabetes?

Choosing slow-carb foods or foods with a lower glycemic index rating will impact blood sugar levels gradually, which make them a good fit for those looking to maintain stable blood sugar levels. These foods are also rich in fiber, minerals, and nutrients that can help with diabetes management.

<p class="pro-tip"> You can read more about how Signos works here.</p>

Get more information about weight loss, glucose monitors, and living a healthier life
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.
  • Item 1
  • Item 2
  • item 3
Get more information about weight loss, glucose monitors, and living a healthier life
Thank you! Your submission has been received!
Oops! Something went wrong while submitting the form.

Topics discussed in this article:


  1. American Diabetes Association. (n.d.). Carb Counting and Diabetes | ADA. American Diabetes Association. Retrieved April 28, 2022, from 
  2. Austin, G. L., Ogden, L. G., & Hill, J. O. (2011, February 10). Trends in carbohydrate, fat, and protein intakes and association with energy intake in normal-weight, overweight, and obese individuals: 1971–2006. The American Journal of Clinical Nutrition, 93(4), 836-843. 
  3. Harvard School of Public Health. (n.d.). Carbohydrates and Blood Sugar | The Nutrition Source | Harvard TH Chan School of Public Health. Harvard T.H. Chan School of Public Health. Retrieved April 28, 2022, from 
  4. Holesh., J. E., Aslam, S., & Martin, A. (2021, July 26). Physiology, Carbohydrates. Stat Pearls. /
  5. Mitchell, H. L. (2008, January). The Glycemic Index Concept In Action. The American Journal of Clinical Nutrition, 87(1), 244-246. 
  6. UK, D. (2019, January 15). Simple vs Complex Carbohydrates - Difference Between Simple Sugars and Starches. Diabetes UK. Retrieved April 28, 2022, from 
  7. Whole Grains Council. (n.d.). Whole Grains A to Z. Whole Grains 101.
  8. Giugliano, D., Maiorino, M. I., Bellastella, G., & Esposito, K. (2018). More sugar? No, thank you! The elusive nature of low carbohydrate diets. Endocrine, 61(3), 383–387.

About the author

Julia Zakrzewski is a Registered Dietitian and nutrition writer. She has a background in primary care, clinical nutrition, and nutrition education. She has been practicing dietetics for four years.

View Author Bio

Please note: The Signos team is committed to sharing insightful and actionable health articles that are backed by scientific research, supported by expert reviews, and vetted by experienced health editors. The Signos blog is not intended to diagnose, treat, cure or prevent any disease. If you have or suspect you have a medical problem, promptly contact your professional healthcare provider. Read more about our editorial process and content philosophy here.

Interested in learning more about metabolic health and weight management?

Try Signos.