Which Carb Is the Most Filling? The Satiety Index Explained

November 2, 2025 •

4 min read

According to a landmark 1995 study published in the European Journal of Clinical Nutrition, boiled potatoes scored highest on the Satiety Index, making them the most filling carb tested. Understanding which carb is the most filling involves looking beyond simple calories to factors like fiber, protein, and water content to manage hunger effectively.

Quick Summary

This guide explores which carbohydrates promote the greatest feelings of fullness based on the Satiety Index. It delves into the reasons behind varying satiety levels, comparing complex and simple carbs, and provides examples of the most satiating choices to help control appetite.

Key Points

Boiled Potatoes are Number One: A 1995 study identified boiled potatoes as the most satiating carbohydrate, scoring over 300% on the Satiety Index.
Fiber is Key: High-fiber carbohydrates, like oatmeal, legumes, and whole grains, slow digestion and promote long-lasting fullness.
Water Increases Bulk: Carbs with high water content, such as boiled potatoes, increase stomach volume and trigger fullness signals with fewer calories.
Processing Reduces Satiety: Refined carbs like white bread and pastries are less filling than whole, unprocessed options and can lead to hunger spikes.
Pair with Protein: Combining carbohydrates with a protein source, such as adding lentils to a rice dish, significantly enhances satiety.
Focus on Whole Foods: Prioritizing whole grains, vegetables, and legumes over refined products is the best strategy for sustainable hunger management.

Understanding the Satiety Index

The feeling of fullness, or satiety, is a crucial factor in managing appetite and weight. In 1995, a pivotal study by researchers at the University of Sydney developed the Satiety Index to rank common foods by their ability to satisfy hunger. The index uses white bread as a baseline, assigning it a score of 100%. Foods with a score higher than 100% are more filling, while those with a lower score are less so. By focusing on foods with a higher satiety index score, you can feel more satisfied for longer after a meal, which can naturally lead to reduced calorie intake.

The Most Filling Carbs

Not all carbohydrates are created equal when it comes to keeping hunger at bay. The most satiating carbs tend to be whole, unprocessed foods rich in fiber and water. Here are the standout options based on scientific evidence:

Boiled Potatoes

Topping the Satiety Index with a score of 323%, boiled potatoes are the king of filling carbs. Potatoes were unfairly demonized for years, but their high ranking is due to a combination of factors. Their high water content adds bulk without extra calories, and they are packed with fiber, vitamins, and minerals. The specific preparation method is key; boiled or baked potatoes are far more satiating than their fried counterparts, like french fries, which scored significantly lower.

Oatmeal (Porridge)

As a popular and filling breakfast choice, oatmeal (porridge) has an impressive Satiety Index score of 209%. Oats contain a type of soluble fiber called beta-glucan, which forms a viscous, gel-like substance in the stomach. This slows down digestion and delays stomach emptying, helping to prolong the feeling of fullness. The high fiber and water-absorbing capacity make it a powerful ally for appetite control.

Legumes and Pulses

Legumes, including beans, lentils, and peas, are nutritional powerhouses loaded with both fiber and plant-based protein. This combination of macronutrients is highly effective for promoting satiety. Studies show that people who eat meals with pulses feel significantly more full than those who consume equivalent calorie meals without them. This makes lentils and beans excellent filling additions to soups, salads, and stews.

Whole Grains

Unlike refined grains (like white bread or white pasta) that have been stripped of their fiber and nutrients, whole grains retain all parts of the grain kernel. This high fiber content, along with B vitamins and minerals, contributes to a slower digestion process and a more gradual release of glucose into the bloodstream. Examples include brown rice, whole wheat bread, whole wheat pasta, and quinoa.

Factors Affecting Satiety in Carbs

Several key factors determine how filling a carbohydrate will be. Recognizing these can help you make more informed food choices.

Fiber Content: Fiber is indigestible, meaning it adds bulk to food and slows down the digestive process. This prolongs the time nutrients spend in your system, which helps you feel full for longer.
Water Content: Foods with high water content, like boiled potatoes, increase the volume of food in your stomach. This triggers stretch receptors in the stomach lining, sending signals of fullness to the brain.
Low Energy Density: This refers to the number of calories per unit of weight. Foods with a low energy density, like many whole fruits and vegetables, allow you to eat a larger portion for fewer calories, contributing to greater fullness.
Protein Combination: While protein is not a carb, pairing carbs with a protein source can significantly boost satiety. Protein is the most satiating macronutrient, and its presence slows digestion and triggers key satiety hormones.
Processing and Form: The physical form of a food matters. Solid carbs tend to be more filling than liquid carbs because they require more chewing and take up more space in the stomach. Refined carbs are processed quickly, leading to rapid blood sugar spikes and crashes that leave you hungry sooner.

Comparison of Satiating Carbs (Based on Satiety Index)

This table highlights the difference in satiety scores between some of the most and least filling carbohydrate-rich foods, based on the 1995 Satiety Index study.


Food Type	Satiety Index Score (%)
Boiled Potatoes	323
Porridge (Oatmeal)	209
Brown Pasta	188
Whole-meal Bread	157
White Rice	138
White Pasta	119
French Fries	116
White Bread	100
Croissant	47

The Verdict on the Most Filling Carb

When considering which carb is the most filling, boiled potatoes are the clear winner according to the Satiety Index study. However, the best approach for sustained fullness isn't to rely on just one food. Incorporating a variety of high-fiber, low-energy-density carbohydrates—such as oats, whole grains, and legumes—into a balanced diet with adequate protein is the most effective strategy. This approach utilizes multiple mechanisms for satiety, including high fiber, increased bulk, and a steady release of energy, helping you feel satisfied for longer and manage your weight more effectively.

For a deeper dive into the original study, see the Satiety Index of Common Foods.

Frequently Asked Questions

The Satiety Index is a ranking system created by Australian researchers in 1995 to measure how filling various common foods are. It uses white bread as a baseline (100%), and other foods are scored relative to it based on how satisfied test subjects felt after eating an equal calorie portion.

Complex carbohydrates are generally more filling than simple carbohydrates. This is because complex carbs contain more fiber and take longer to digest, providing a gradual release of energy and sustained fullness. Simple carbs are digested quickly, often leading to rapid blood sugar fluctuations and a faster return of hunger.

Fiber makes a carb more filling in several ways: it adds bulk without adding calories, it slows down the digestion process, and soluble fiber (found in oats and legumes) forms a gel in the stomach that helps delay gastric emptying. All of these mechanisms contribute to a prolonged feeling of fullness.

Boiled potatoes are exceptionally filling due to their high water content and low energy density, meaning they provide a large volume of food for relatively few calories. They also contain resistant starch and fiber, which aid in sustained fullness, especially when consumed with the skin.

Yes, preparation method significantly impacts satiety. For example, fried potatoes (french fries) have a much lower satiety index score (116%) than boiled potatoes (323%), primarily because of the added fat and reduced water content. Solids are also generally more filling than liquids.

To increase the satiety of your meals, choose whole, unprocessed carbohydrates over refined ones, add plenty of fiber-rich vegetables and legumes, and pair your carbs with a source of protein. These strategies will slow digestion and prolong feelings of fullness.

Protein is the most satiating macronutrient and works synergistically with carbohydrates. It slows digestion and triggers the release of hormones that signal fullness to the brain, effectively extending the satiating effect of the meal.

While most whole grains are more filling than refined grains, their satiety levels can vary. Factors like fiber content, protein content, and density influence how filling they are. For example, oatmeal and wild rice are often cited as being particularly satiating due to high fiber and protein levels, respectively.