Which Food Is More Filling? Understanding the Science of Satiety

November 8, 2025 •

4 min read

According to the Satiety Index, a scientific ranking of foods based on their filling power, boiled potatoes scored highest with a remarkable 323% more satiating effect than white bread. Understanding which food is more filling and the reasons behind it can be a powerful tool for controlling appetite and achieving a healthier diet.

Quick Summary

This article explores the science behind what makes certain foods more satiating, including high protein and fiber content, and low energy density. Learn about the Satiety Index and how to incorporate the most filling foods into your diet to manage hunger and support weight loss goals.

Key Points

High-Satiety Factors: Foods high in protein, fiber, and water content are the most filling due to their impact on hormones, digestion, and volume.
The Satiety Index: Boiled potatoes rank as the most satiating food, with a score of 323% compared to white bread, according to the 1995 Satiety Index.
Protein Power: Protein is the most satiating macronutrient, regulating hunger hormones like ghrelin to keep you feeling full longer.
Fiber for Fullness: High-fiber foods, especially whole grains, legumes, and vegetables, add bulk and slow digestion, preventing rapid hunger spikes.
Energy Density Matters: Low-energy-dense foods, rich in water, allow for larger, more satisfying portion sizes for fewer calories.
Mindful Meal Structure: Strategically combining protein and fiber, starting with soup or salad, and prioritizing whole foods over processed ones can maximize meal satisfaction.
Cooking Method Impact: How you cook your food can affect its satiating power; for instance, boiled potatoes are more filling than fried ones.

The Science Behind Satiety and the Satiety Index

Satiety is the feeling of fullness and satisfaction that prevents you from eating further after a meal. It's a complex process involving hormones, nerves, and physical stomach distension. In 1995, researchers at the University of Sydney developed the Satiety Index to measure how well 38 common foods satisfied hunger for up to two hours after consumption. The index uses white bread as a baseline with a score of 100%, and foods are ranked higher or lower based on their satiating effects. This tool reveals that some foods are far more effective at staving off hunger, even with the same calorie count.

Several key factors determine a food's satiety value:

High Protein Content: Protein is widely considered the most satiating macronutrient. It influences key hunger hormones like ghrelin and leptin, signalling to the brain that you are full and satisfied.
High Fiber Content: Fiber adds bulk to food without adding calories, slowing down digestion and delaying stomach emptying. This sustained digestion keeps you feeling full for longer.
Low Energy Density: Foods with low energy density contain fewer calories per gram, typically due to high water or fiber content. This allows you to eat a larger portion for the same number of calories, physically stretching your stomach and signalling fullness.
Volume and Texture: Foods that are higher in volume, like soups, or require more chewing, like raw vegetables, contribute to a greater sense of fullness by occupying more space and increasing eating time.

Top Foods that are More Filling

Based on scientific research, including the Satiety Index, certain whole foods stand out for their ability to promote lasting fullness. Incorporating these into your diet can be a strategic way to manage appetite and weight.

Vegetables and Legumes

Boiled Potatoes: As the most filling food on the Satiety Index, boiled potatoes are rich in resistant starch, fiber, and water, which contributes significantly to their low energy density.
Legumes: Foods like beans, lentils, and chickpeas are packed with both protein and fiber, making them an incredibly filling combination. They digest slowly and contribute to feelings of satisfaction.
Leafy Greens and Cruciferous Vegetables: High in water and fiber, vegetables like spinach, broccoli, and carrots add significant bulk to meals with minimal calories. This allows for a large plate of food that is both satisfying and low in energy density.

Protein Sources

Eggs: Nutrient-dense and high in protein, eggs are a powerful breakfast choice for curbing hunger throughout the morning. Studies show an egg breakfast can lead to lower calorie intake later in the day.
Fish and Lean Meats: High-quality protein from sources like fish (especially fatty fish rich in omega-3s) and lean beef or chicken has a potent satiating effect.
Greek Yogurt and Cottage Cheese: These low-fat dairy options are high in protein, which helps prolong feelings of fullness. Greek yogurt, in particular, has been shown to reduce hunger compared to lower-protein snacks.

Whole Grains and Fruits

Oatmeal: Rich in soluble fiber (beta-glucan), oats soak up water to create a thick, slow-digesting meal that promotes fullness.
Whole Fruits: Eating whole fruits rather than juices is more satiating due to the fiber content. The water and fiber in fruits like apples and oranges contribute to bulk and delay stomach emptying.
Popcorn: As a high-fiber whole grain, air-popped popcorn offers a low-calorie, high-volume snack that can satisfy hunger effectively.

Satiety Index Comparison Table

(Adapted from the 1995 Satiety Index study by Holt et al., using white bread as the baseline 100% reference).


Food Category	High Satiety Score Examples	Low Satiety Score Examples
Carbohydrates	Boiled Potatoes (323%), Brown Pasta (188%), Oatmeal (209%)	Croissant (47%), White Bread (100%), White Pasta (119%)
Protein-Rich	Fish (225%), Beef (176%), Eggs (150%)	Cheese (146%)
Fruits	Apples (197%), Oranges (202%)	Grapes (162%)
Snacks	Popcorn (154%), All-Bran (151%)	Cake (65%), Doughnuts (68%), Mars Bar (70%)

Maximizing Fullness in Your Diet

Simply choosing the right foods is a great start, but how you prepare and consume them also plays a role in maximizing satiety.

Combine Protein and Fiber

Aim to include a source of both protein and fiber in every meal. This powerful combination works synergistically to slow digestion, stabilize blood sugar, and prolong satisfaction. For example, add grilled chicken to a large spinach salad with chickpeas, or mix berries and almonds into your Greek yogurt.

Choose Unprocessed Foods

Whole, unprocessed foods generally provide greater satiety than their processed counterparts. This is because processing often strips away fiber and other nutrients that contribute to fullness, while adding fat and sugar that increase energy density. The texture and chewing required for whole foods also contributes to a greater sense of satisfaction.

Prioritize Water-Rich Foods

Increasing the water content of your meals can help you feel full on fewer calories. Start a meal with a broth-based soup or a large salad to fill your stomach with low-energy-dense volume. Drinking a glass of water before a meal can also aid in feeling full.

Conclusion: Making Smarter, More Satisfying Choices

Focusing on high-satiety foods is a simple yet effective strategy for improving your nutrition and managing your weight sustainably. Instead of feeling deprived by calorie restriction, you can feel satisfied and full by prioritizing foods naturally high in protein, fiber, and water. A meal built around boiled potatoes, eggs, fish, and legumes, and enhanced with high-volume vegetables and fruits, is not only more filling but also packed with essential nutrients for overall health. By understanding which food is more filling, you can make smarter dietary choices that lead to greater satisfaction and lasting results. For further insights on creating satisfying meals, refer to resources like this guide from Healthline on filling foods.

Frequently Asked Questions

Based on the Satiety Index developed in 1995, boiled potatoes are considered the most filling food, scoring 323% more satiating than white bread.

Yes, protein is the most satiating macronutrient. It slows digestion and influences hunger-regulating hormones, helping you feel fuller for a longer period compared to fats or carbohydrates.

Fiber adds bulk to food without adding significant calories and slows the digestive process. This delays stomach emptying and leads to a prolonged sense of fullness.

Whole fruits are very filling due to their fiber and water content. However, fruit juice is less satiating because the fiber has been removed during processing, concentrating the sugar and calories.

Foods with low energy density (fewer calories per gram) are more filling. These are typically foods with high water and fiber content, which take up more space in your stomach, triggering a feeling of fullness on fewer calories.

Yes, soups can be very filling. The high water content in broth-based soups adds volume, which helps to stretch the stomach and stimulate fullness signals with minimal calories.

Yes, preparation matters. For example, a boiled potato is significantly more satiating than a fried potato or french fries. Minimally processed or less-cooked foods can also sometimes increase chewing time, which helps with satiety.

For maximizing satiety, high-protein dairy options like Greek yogurt and cottage cheese are excellent choices. While fats do slow digestion, protein has a stronger immediate impact on hormonal hunger signals.

Excellent high-satiety snacks include a handful of nuts, Greek yogurt with berries, air-popped popcorn, a hard-boiled egg, or cottage cheese with some cucumber slices.