Deep Dive: Carbohydrates

Carbohydrates play a crucial role in fueling the body and supporting long-term health. In this deep dive, we’re breaking down the different types of carbs, the importance of fiber, choosing carbs for quick vs. sustained energy, and what the science says about low-carb and no-carb diets.

Carbs 101

Carbohydrates, alongside protein and fat, comprise the holy trinity of macronutrients. They are also your body’s primary source of energy, and fuel everything from brain function to muscle movement!

Simple vs. Complex Carbohydrates

The most beneficial sources of carbohydrates are complex carbohydrates found in minimally processed whole foods like grains, fruits, vegetables, and legumes. The fiber in these foods slows digestion and helps provide sustained energy, stable blood sugar levels, and long-term health benefits.

In contrast, the simple carbohydrates found in refined and processed foods like white bread, sodas, and candy are digested quickly. This can lead to rapid spikes and crashes in blood sugar. That doesn’t mean you can’t eat them, but that you should be aware of how to pair them to avoid a crash. This may include strategies like pairing with fat and protein, limiting portion sizes, or making sure you consume them alongside fiber-rich foods.

Simple carbs:	Complex carbs:
🧊 Table sugar 🍭 Candy and sweets 🥤 Sugary drinks 🍞 White bread 🥐 Pastries 🧃 Fruit juice (without pulp) -Higher GI index -Digested quickly -Provide rapid energy -Fullness is short-lived -Can lead to blood sugar spikes	🌾 Whole grains 🥣 Oats, barley, brown rice 🫘 Beans and lentils 🍠 Sweet potato 🥒 Squash 🍎Fruit (especially with skin) – Lower GI index -Take longer to break down -Longer-lasting energy source -Provide additional health benefits -Don’t spike blood sugar as much as simple sugars

On your plate: how many carbs to eat

Carbs should make up 45-65%, or half, of your daily calorie intake (needs vary based on age, activity level, and health). For most people, that equals about 225-325 grams per day.

For an idea of what 225-325 grams looks like, here are some approximate carb counts of common foods:

🍎1 medium apple: 25g carbs

🍞2 slices whole wheat bread: 24g carbs

🍚1 cup cooked white rice: 45g carbs

🍝1 cup cooked pasta: 40g carbs

🥔1 medium baked potato, with skin: 37g carbs

🫘1 cup cooked beans: 40g carbs

🍌1 medium banana, ripe: 27g carbs

🥦1 cup cooked broccoli: 11g carbs

🍪3-inch chocolate chip cookie: 20g carbs

Our easy rule of thumb for meals is to fill 25% of your plate with starch, 25% with protein, and the rest with non-starchy vegetables (plus a serving of healthy fat)!

Focus on fiber

Fiber is a type of carbohydrate that the body can’t fully digest — but it’s still essential for good health. Unlike other carbs that break down into glucose, fiber passes through the digestive system mostly intact. 

Here’s why it’s important:

• Supports digestive health
• Promotes fullness
• Helps regulate blood sugar by slowing how quickly glucose enters the bloodstream
• Lowers cholesterol levels
• Feeds beneficial gut bacteria, especially soluble fiber and resistant starch

Digesting carbs step-by-step

1. Starts in the Mouth

The enzyme amylase in your saliva starts breaking down starches into smaller sugar molecules.

2. Down the Esophagus to the Stomach

Partially broken-down carbs travel through the esophagus to the stomach, where they’re mixed with stomach acids. These acids prepare the food for the next stage of digestion.

3. Into the Small Intestine

Here, the pancreas releases pancreatic amylase to continue breaking down starches into even smaller sugar units like maltose, sucrose, and lactose.

4. Breaking Down to Glucose

Enzymes maltase, sucrase, and lactase in the lining of the small intestine break those sugars down into glucose, the simplest form of carbohydrate. This is the main sugar your body uses for energy.

5. Absorption Into the Bloodstream

Glucose is absorbed through the walls of the small intestine into the bloodstream, where it raises your blood sugar (blood glucose) levels. From there, it travels to your cells, where it’s used for energy.

6. Stored for Later

If you don’t need all that glucose right away, your body stores some of it in your liver and muscles as glycogen. When you need extra energy later—like during exercise or between meals—your body taps into these glycogen stores.

How the body processes excess carbs:

• Excess glucose is stored as fat: When you consume more carbohydrates than your body needs for immediate energy or glycogen storage, the extra glucose is converted into fat and stored in adipose tissue. This can lead to weight gain over time.
  
• Frequent blood sugar spikes can impact insulin sensitivity: A diet high in simple carbs like sweets and sugary drinks causes repeated spikes in blood sugar and insulin levels. This may contribute to insulin resistance over time — a risk factor for type 2 diabetes.
  
• Low fiber intake from processed carbs can disrupt hunger cues: Fiber helps promote fullness. Without it, it’s easier to overeat and experience energy crashes, leading to increased cravings and poor blood sugar control.
  
• High intake of added sugars is linked to chronic diseases: Diets high in added sugars, found predominantly in ultra-processed foods, are associated with a higher risk of heart disease, non-alcoholic fatty liver disease, and inflammation, especially when combined with low physical activity.

Carb Myth-Busting

“Gluten is bad for me.”

❌ False (for most people). Gluten is only harmful for people with medical conditions like celiac disease or a gluten allergy. Others have no reason to avoid it! Whole grains like whole wheat and farro offer important nutrients and fiber. Avoiding gluten unnecessarily can lead to reduced intake of fiber-rich and delicious foods.  

“Low-carb diets are the best for weight loss.”

❌ False (for most people). Low-carb diets can work for some individuals short-term, but many dietary patterns — including those with carbs — can support weight loss when they’re nutrient-dense and sustainable. A recent study even found that low-carb diets are associated with an increased risk of type 2 diabetes, likely due to increased fat intake and lack of fiber.

“Fruit has too much sugar and should be limited.”

❌ False. Whole fruits contain natural sugars but also provide fiber, antioxidants, and essential nutrients. Fruit is a nutritious, energizing part of the diet.

“I should avoid simple carbs.”

✔️Partially true. Simple carbs like candy and soda offer little nutrient value, but taste delicious In moderation. They can be part of a balanced diet, but choose to pair them with fat and protein to avoid blood sugar spikes. 

5 Complex Carbs from Around the World

Many of the most nutrient-dense complex carbs have deep roots in cultural food traditions. These five global staples deliver both rich flavor and lasting fiber.

1. Fonio (West Africa)
A tiny ancient grain with a nutty flavor and fluffy texture, fonio is rich in iron, B vitamins, and amino acids. It cooks quickly and is a great alternative to couscous or quinoa.

2. Taro (Asia, Pacific Islands, Caribbean)
This starchy root vegetable is packed with fiber, potassium, and resistant starch. Commonly used in curries, stews, or steamed with coconut milk, taro offers a creamy, slightly sweet flavor.

3. Teff (Ethiopia)
The base of traditional injera bread, teff is a gluten-free grain that’s high in iron, calcium, and prebiotic fiber. Its mild, nutty flavor makes it perfect for porridge, baked goods, or grain bowls.

4. Freekeh (Middle East, North Africa)
Made from young, roasted green wheat, freekeh is rich in fiber, protein, and antioxidants. Its smoky flavor pairs beautifully with roasted vegetables, herbs, and legumes.

5. Amaranth (Central and South America, India)
Once a staple of Aztec cuisine, amaranth is a high-protein, gluten-free grain that also contains calcium and magnesium. It has a slightly earthy taste and works well in porridges, pilafs, or soups.

Work with a Culina Health RD

Looking for more actionable nutrition insights, tailored specifically to your individual budget, health goals, and dietary preferences? The team of Registered Dietitians at Culina Health is here for you! Book your first session here to take the next step in your health journey—plus, we’re in-network with most major insurance plans.