What is the number one satiating food? Discover the science of fullness

According to a landmark 1995 study published in the European Journal of Clinical Nutrition, one food scored over 300% higher than white bread on the Satiety Index. The results identified what is the number one satiating food, providing powerful insight for anyone looking to control their appetite and manage their weight.

Quick Summary

This article explains the Satiety Index and reveals which food ranked highest for fullness. It explores the nutritional factors—like protein, fiber, and water content—that contribute to making a food satiating.

Key Points

• Boiled Potato is Number One: A 1995 study found boiled potatoes to be the most satiating food, scoring 323% on the Satiety Index, over three times more filling than white bread.

• Protein is Powerful: High-protein foods like fish, eggs, and lean meats trigger the release of satiety hormones and take longer to digest, helping you feel full.

• Fiber Adds Volume: Both soluble and insoluble fiber, found in oats, legumes, and fruits, add bulk and slow digestion, leading to increased fullness.

• Volume Matters: Foods with high water content and low energy density, such as soups and most fruits/vegetables, fill the stomach more for fewer calories.

• Preparation is Key: Cooking methods significantly impact satiety; boiled or baked potatoes are far more filling than fried ones, and cooling potatoes increases their resistant starch.

• Combine Nutrients for Best Results: Eating meals that include a combination of high-protein, high-fiber, and high-volume foods is the most effective strategy for lasting fullness.

The Science of Feeling Full: The Satiety Index

Satiety refers to the feeling of fullness or satisfaction after eating, which plays a crucial role in controlling appetite and managing weight. To scientifically measure and compare the satiating effect of different foods, researchers at the University of Sydney created the Satiety Index (SI) in 1995.

In the study, participants were fed isoenergetic (240-calorie) portions of 38 different foods. Their perceived hunger was then measured over a period of time. The results were ranked against white bread, which was given a baseline score of 100%. Foods with a score above 100% are considered more satiating per calorie than white bread, while those below 100% are less so. The findings revealed significant differences in the satiating capacity of foods, proving that not all calories are created equal when it comes to feeling full.

The Verdict: What is the Number One Satiating Food?

Based on the Satiety Index study, the number one satiating food is the boiled potato, with a score of 323%. This means that, calorie for calorie, a boiled potato is more than three times as filling as white bread. This result has surprised many, as potatoes were once demonized for their carbohydrate content. The key, however, lies in how the potato is prepared and its unique nutritional composition.

Why a Simple Potato Packs a Punch

The humble boiled potato is a powerhouse of properties that promote fullness. Its effectiveness stems from a combination of factors:

• High Water Content: Potatoes have a high water content and low energy density, meaning they provide significant volume for relatively few calories. This volume increases gastric distension, which sends signals to the brain that you are full.
• Resistant Starch: When potatoes are cooked and then cooled, their starch turns into a type of fiber called resistant starch. This starch is not easily digested, which delays stomach emptying and sustains the feeling of fullness for longer. It also feeds beneficial gut bacteria.
• Vitamins and Minerals: Potatoes are rich in vitamins and minerals, including vitamin C and potassium. A nutrient-rich food can satisfy the body's needs more effectively, potentially reducing cravings.

Key Factors That Increase Satiety

While the boiled potato may hold the top spot, other foods also score high due to specific nutritional characteristics. Understanding these factors can help you build more satisfying meals.

Protein: The Satiety Superstar

Protein is widely considered the most satiating macronutrient. It affects satiety in several ways:

• Hormonal Regulation: Protein triggers the release of satiety hormones like peptide YY and GLP-1, which communicate to the brain that you are satisfied.
• Slower Digestion: Protein takes longer to digest than carbohydrates, providing a more sustained release of energy and prolonging the feeling of fullness.
• Higher Thermic Effect: The body expends more energy to digest and metabolize protein than other macronutrients.

Excellent protein-rich options include fish (especially ling fish, which scored 225% on the SI), eggs, lean meats, and Greek yogurt.

Fiber: Adding Bulk and Slowing Digestion

Dietary fiber is another critical component for promoting fullness. Both soluble and insoluble fiber play a role:

• Soluble Fiber: Found in foods like oats and apples, soluble fiber forms a gel-like substance in the stomach that slows digestion and delays stomach emptying.
• Insoluble Fiber: Provides bulk to food, filling up the stomach and contributing to feelings of fullness.
• Legumes: Packed with both protein and fiber, legumes like beans and lentils are highly satiating. A study found participants felt 31% fuller after eating pulses compared to meals without them.

High Water Content: The Volume Advantage

Foods with a high percentage of water, such as fruits, vegetables, and soups, are often very filling. They add volume to a meal without adding many calories. This is the same principle that makes potatoes so effective. In fact, research suggests soups can be more filling than a solid meal with the same ingredients.

Satiety Index Comparison Table

Food Category	High Satiety Examples (SI Score)	Low Satiety Examples (SI Score)	Satiety Factor	Key Takeaway
Carbohydrate-Rich	Boiled Potatoes (323%), Oatmeal (209%), Brown Pasta (188%)	Croissant (47%), Doughnuts (68%), Cake (65%)	Water, Fiber, Resistant Starch	Processing and cooking method drastically alter satiety.
Protein-Rich	Ling Fish (225%), Eggs (150%), Beef (176%)	N/A (Protein consistently high)	High Protein, Slow Digestion, Hormonal Release	Protein is consistently the most satiating macronutrient.
Snacks/Confectionery	Popcorn (154%), All-Bran (151%)	Mars Candy Bar (70%), Peanuts (84%)	Fiber, Volume	Choose high-fiber, low-energy-density snacks for fullness.
Fruits	Oranges (202%), Apples (197%), Grapes (162%)	Bananas (118%)	Fiber, Water	Whole fruit is more filling than juice due to fiber content.

Putting Satiating Foods Into Practice

Incorporating highly satiating foods into your diet is a smart strategy for managing weight and curbing appetite. Here are some simple ways to use the science of satiety in your daily meals:

1. Prioritize Protein at Every Meal: Aim to include a lean protein source with each meal, such as eggs at breakfast, chicken or fish at lunch, and legumes or tofu at dinner.
2. Go for High-Fiber Carbs: Swap refined carbs for whole grains, fruits, and vegetables. Consider a bowl of oatmeal for breakfast or adding legumes to your salad for lunch.
3. Use Potatoes Strategically: To maximize the satiating effect of potatoes, boil or bake them and let them cool before eating or reheating. This increases their resistant starch content. Pair them with a protein source to further enhance fullness.
4. Start with Soup: A broth-based soup loaded with vegetables can be a very filling appetizer. The high water and fiber content will help curb your appetite before the main course.
5. Snack Smart: Instead of reaching for processed, high-sugar snacks, opt for naturally filling options like an apple with nut butter, a handful of almonds, or Greek yogurt with berries.

For additional insights into the original research on satiety, you can explore the 1995 Satiety Index study on ResearchGate: https://www.researchgate.net/publication/15701207_A_Satiety_Index_of_common_foods.

Conclusion

The concept of satiety, measured by the groundbreaking Satiety Index, provides a powerful and evidence-based approach to eating for satisfaction. While the boiled potato stands out as the number one satiating food, the overall lesson is more important: prioritize foods rich in protein, fiber, and water, and choose whole, unprocessed options over refined, high-sugar alternatives. By understanding the nutritional factors that drive fullness, you can make more informed choices, control your appetite effectively, and achieve your weight management goals without feeling deprived.

Frequently Asked Questions

What is the Satiety Index?

The Satiety Index is a ranking system that measures how filling different foods are, based on a 1995 study where participants were fed isocaloric portions of food. White bread was used as the baseline, with a score of 100%.

Why are boiled potatoes so satiating?

Boiled potatoes are highly satiating due to their high water content, low energy density, and fiber. When cooled, they also produce resistant starch, which takes longer to digest and helps prolong fullness.

Are other forms of potato also highly satiating?

No. The Satiety Index found that boiled potatoes were the most satiating, scoring significantly higher than french fries (116% SI), which are high in fat and less filling.

Besides potatoes, what are other very satiating foods?

Other foods that score high on the Satiety Index include ling fish, oatmeal/porridge, oranges, and apples. Eggs, lean meats, and legumes are also excellent choices for promoting fullness.

How do protein and fiber increase fullness?

Protein is the most satiating macronutrient, triggering satiety hormones and requiring more energy to digest. Fiber adds bulk to food and slows down digestion, prolonging the feeling of fullness.

Are liquid foods less filling than solid foods?

Not always. While some liquids can be less filling, soups are an exception. Because they contain a lot of water and can be packed with fiber, soups can be very filling and may even stay in the stomach longer than some solid meals.

How can I incorporate more satiating foods into my diet for weight management?

To eat for better satiety, focus on whole, unprocessed foods. Prioritize lean protein and fiber at every meal, increase your intake of high-volume, low-energy-density fruits and vegetables, and opt for healthy snacks like nuts or yogurt instead of sugary options.