It’s golden, flaky, and for some people, just irresistible. A good croissant sounds like a perfect breakfast, especially when paired with a cappuccino.

But give it two hours, and you’re probably hungry again. You might think you’re just weak-willed, or try to fill up with butter or jam. But the truth is that the croissant isn’t just failing to keep you full — it’s possibly the worst choice on the menu.

According to one of the most underrated food studies ever published, the croissant sits dead last on the satiety index, a ranking of how full different foods make us feel, calorie for calorie.

Boiled potatoes came out on top. Croissants hit rock bottom. Let’s break down what’s in between.

The croissant just doesn’t cut it

Satiety isn’t just in calories, protein, or how chewy something is. When we eat, our bodies react to multiple things like weight, volume, protein content, fiber, and water — physical signals that say, ‘Hey, we’re good now.’ So counting how filling something is isn’t so straightforward.

In a 1995 study, researchers at the University of Sydney gave participants 240-calorie servings of 38 common foods. Then they waited. How long did it take before people wanted to eat again?

Each food’s Satiety Index was calculated by comparing the area under the curve (AUC) of satiety responses to that of white bread, which was set at 100. Foods scoring above 100 were more filling than white bread; those below were less. This simple, clever method revealed which foods kept people fuller for longer — regardless of calorie count.

Croissants are a disaster on every front:

• Low in protein: Protein is the most hunger-fighting nutrient. Croissant? Forget about any protein.
• Low in fiber: Fiber bulks up in the gut, slows digestion, and keeps you full longer. Think oatmeal (209) or apples (197) for fiber.
• High in fat, low in water: That buttery flake you love? It’s dry, calorie-dense, and slips through the digestive system like a cheat code, leaving little residue to signal “full.”

Even worse, croissants hit the pleasure centers hard. The more “palatable” a food is — rich, sweet, melty, or crispy — the more we tend to overeat it.

This isn’t about banning croissants. But if your goal is to feel full, energized, and focused, especially when trying to manage weight, they’re working against you.

So what foods are good?

Unsurprisingly, unprocessed foods tend to be more filling. But it’s not just fruits and veggies; oatmeal, bran, eggs, and cheese are all very filling.

• Boiled potatoes (323): The king of satiety. Surprisingly low in calories for their weight, and packed with water and fiber.
• Oatmeal (209): Warm, slow-digesting, and rich in fiber. Especially good with a bit of fruit.
• Eggs (150): High in protein, portable, and far more filling than toast.
• Popcorn (154): Air-popped and unbuttered, it’s bulky and low-calorie — a brilliant snack.
• Whole grain breads (157): The fiber makes all the difference. Smear on some peanut butter for extra protein.

These foods don’t just fill your stomach — they hang around. They give your digestive system something to work with. And that translates into fewer cravings, better focus, and maybe, just maybe, fewer 3 p.m. cookie raids.

“Foods that contain large amounts of fat, sugar, and/or starch have low Fullness Factors, and are much easier to overeat. Foods that contain large amounts of water, dietary fiber, and/or protein have the highest Fullness Factors. These high-FF foods, which include most vegetables, fruits, and lean meats, do a better job of satisfying your hunger,” the study authors write.

Why this matters a lot

Here’s the thing: we’ve known this for years. This study is three decades old. But it’s very timely now — because we’re still caught in a food culture obsessed with calories, macros, and willpower, while largely ignoring satiety. Wellness trends chase protein powders and intermittent fasting, yet millions of people feel still hungry an hour after eating. Meanwhile, ultra-processed foods dominate store shelves, packing in fat and sugar with barely any fiber or water — a perfect recipe for low satiety and overeating.

Obesity isn’t just about calories. It’s about hunger. And most diets fail because they ignore that fundamental fact. There’s no real need to go hungry just to lose weight. Instead, you can feed your hunger the smart way, and knowing about this satiety index can help you stay on track.

This insight also has broader implications — for public health, school meals, even food subsidies. Why do we subsidize corn syrup and white bread, when plain boiled potatoes outperform both? We don’t need more willpower. We need better tools.

Obesity is one of the biggest health problems of the 21st century, but its humble index from the ‘90s might just hold the key to smarter, more sustainable eating.