Is Soup a Filling Food? The Science of Satiety in a Bowl

November 18, 2025 •

4 min read

According to researchers at Penn State, eating a low-calorie soup before a meal can reduce overall calorie intake by about 20%. This surprising fact addresses a common question: Is soup a filling food? The answer lies in the unique way soup affects your body's satiety signals, making it an excellent tool for appetite control and weight management.

Quick Summary

Soup is a highly satiating food due to its high water content, which increases volume without adding many calories. Scientific studies confirm that soup can delay gastric emptying, meaning it stays in your stomach longer, and can reduce overall calorie consumption during a meal. The key is to choose nutrient-dense, broth-based varieties packed with fiber and protein.

Key Points

High Water Volume Increases Satiety: The large amount of water in soup fills the stomach more effectively than drinking water alongside a solid meal, signaling fullness to the brain.
Delayed Gastric Emptying: The process of blending solid food with liquid in soup slows digestion, keeping you feeling fuller for a longer period of time.
Low Energy Density: Broth-based soups allow you to consume a large volume of food with fewer calories, a key principle in weight management.
Fiber and Protein are Key: To maximize satiety, incorporate high-fiber vegetables and legumes, as well as lean protein sources into your soup.
Pre-Meal Strategy: Consuming a bowl of low-calorie soup before your main course can significantly reduce overall calorie intake for the meal.
Homemade is Healthiest: Many commercial soups contain excessive sodium and lack the fiber of homemade versions, which are more effective for promoting lasting fullness.

The Surprising Power of Water and Volume

It may seem counterintuitive that a food primarily made of liquid could be so satisfying. However, the high water content is one of the most powerful reasons why soup is a filling food. This principle is a cornerstone of the 'volumetrics' approach to diet, which focuses on eating foods that are high in volume but low in calorie density. When you blend solids with liquid to create soup, the stomach perceives a greater volume of food. This expansion of the stomach wall sends signals to the brain that you are full, suppressing hunger hormones like ghrelin and leading you to feel satisfied on fewer calories.

The Delay of Gastric Emptying

Another critical factor is how soup affects gastric emptying. Unlike simply drinking a glass of water with a solid meal, which passes quickly through the stomach, the liquid in soup is bound with the solid ingredients. This binding effect causes the stomach to empty more slowly, prolonging the feeling of fullness. This is a key reason why a bowl of soup can keep hunger at bay for a longer period compared to a solid meal of the same ingredients and calorie count. Research by Barbara Rolls, a leading expert on satiety, has repeatedly shown the effectiveness of soup preloads in reducing subsequent meal intake.

The Role of Nutrient-Dense Ingredients

Not all soups are created equal when it comes to satiety. To make soup a truly filling meal, the ingredients you choose are paramount. Nutrient-dense additions ensure that your body receives the vitamins, minerals, fiber, and protein it needs to feel satisfied, rather than just full.

For a truly satiating bowl of soup, consider incorporating:

High-Fiber Vegetables: Load your soup with non-starchy vegetables like carrots, celery, spinach, and broccoli. The fiber in these ingredients adds bulk and further delays digestion.
Lean Protein Sources: Ingredients like chicken breast, fish, tofu, or lentils are crucial for a soup that provides lasting fullness. Protein has a strong satiating effect and is essential for muscle health.
Complex Carbohydrates: Whole grains like brown rice, quinoa, or barley, along with legumes such as beans and split peas, provide sustained energy and fiber.
Healthy Fats: A small amount of healthy fat from olive oil, nuts, or avocado can also contribute to the soup's staying power and flavor.

Comparison: Hearty Broth vs. Creamy Bisque

Choosing the right type of soup makes a significant difference in its ability to fill you up healthfully. Here's a comparison to illustrate the impact of ingredients.


Feature	Hearty Broth-Based Vegetable Soup	Creamy Bisque or Chowder
Key Ingredients	Water/stock, vegetables, lean protein (chicken/beans), herbs	Heavy cream, butter, cheese, refined starches
Satiety Mechanism	High water and fiber content, low calorie density	High fat content, can be higher calorie density
Nutrient Profile	High in vitamins, minerals, antioxidants, and fiber	Often high in saturated fat and sodium, lower in fiber
Sustained Fullness	Long-lasting fullness due to fiber and slow digestion	May offer short-term fullness, but can lead to a quicker return of hunger
Best for Weight Management	Highly effective due to low calorie count per volume	Less effective due to high calorie and fat content
Digestive Health	Promotes healthy digestion and gut health with prebiotic fiber	Can be heavier on the stomach; less fibrous

How to Maximize Your Soup’s Filling Potential

To ensure your next bowl is as satiating as possible, consider these practical tips:

Make it a 'Preload': Have a bowl of broth-based soup as an appetizer before your main meal. Studies show this can significantly reduce the total calories you consume.
Bulk it Up: Add a mix of textures and ingredients. The combination of vegetables, legumes, and whole grains keeps the mouth and stomach engaged, enhancing the feeling of satisfaction.
Balance Your Macronutrients: For a main course, a well-balanced soup should contain all three macronutrients: a lean protein source (e.g., lentils, chicken), a complex carbohydrate (e.g., brown rice, potatoes), and plenty of vegetables.
Flavor Matters: Use herbs, spices, and aromatics to build a rich flavor base. This adds to the overall eating experience without increasing calories, leaving you feeling more content.
Avoid Canned Soups (mostly): While convenient, many canned and packaged soups are high in sodium and lack the fiber and nutrients needed for true satiety. Homemade is almost always the better, more filling option. [Find inspiration at BBC Food's soup collection].

Conclusion: The Final Verdict

So, is soup a filling food? The scientific evidence is a resounding yes, particularly when prepared mindfully. The unique combination of high water volume, nutrient density, and slow gastric emptying works together to promote feelings of satiety more effectively than many solid foods. By focusing on hearty, broth-based varieties packed with fiber and lean protein, you can leverage the power of soup to manage your appetite, control portions, and enjoy a delicious, warm, and satisfying meal. Whether as a light starter or a complete main course, soup can be a powerful ally in a healthy diet.

Frequently Asked Questions

Yes, research indicates that soup can be more satiating than an equivalent solid meal. The liquid in soup is combined with the solids, which slows gastric emptying and increases stomach volume, promoting greater feelings of fullness.

Yes, eating low-calorie, broth-based soups can help with weight loss by increasing satiety and reducing overall calorie intake. Studies have shown that a soup 'preload' before a meal can lead to consuming fewer calories overall.

Not all soups are equally filling. Soups that are high in fat and calories (like cream-based versions) or those lacking sufficient fiber and protein will not provide the same lasting satiety as broth-based soups packed with vegetables and lean protein.

To make your soup more filling, add nutrient-dense ingredients. Incorporate high-fiber vegetables (e.g., broccoli, sweet potatoes), lean protein sources (e.g., lentils, chicken, beans), and complex carbohydrates (e.g., brown rice, quinoa).

The form of a soup can influence satiety, though studies have yielded mixed results. Some research suggests pureed soups may lead to a slower rate of gastric emptying compared to chunky ones, potentially enhancing the feeling of fullness.

While bone broth is nutritious, it is not as filling on its own as a hearty, vegetable-packed soup. For a truly satiating meal, it is best to use bone broth as a flavorful base and add other high-fiber and protein-rich ingredients.

Homemade soups are typically more nutritious and filling. Many canned soups are high in sodium and may lack the fresh, fiber-rich vegetables that contribute significantly to satiety and overall health.