The Satiety Game
240 calories of one food can hold you until dinner. The same 240 calories of another has you hungry before the next meeting starts.
Nothing here is a bad food. This is only about which foods keep you full for the calories they cost.
Rides the ferry to a downtown desk by 7:40. Eats something quick at noon, and by three he is standing at the vending machine wondering where the afternoon went. He is not short on willpower. He is short on food that stays with him.
In 1995 a group of researchers fed people equal calorie portions of 38 different foods, 240 calories of each, then asked how full they felt every 15 minutes for the next two hours.
White bread was the yardstick, set at 100. Every other food got a score against it. Higher means people said they stayed fuller. Boiled potatoes came in at 323, the highest of all 38 foods tested.
It is one small study. The honest limits are in Why at the end, and they are worth reading.
Training wheels are on for this one. The dotted spots show you how many go where, and white bread is the yardstick at 100.
PLACEHOLDER · portion pictures are approximations from the weight, not counted servings
Task 1 is done. Task 2 is one vegetable, three ways.
You just sorted six different foods. Task 2 narrows all the way down to one.
The potato scored higher than anything else tested, but that was a boiled potato. Turn the same potato into fries, or into chips, and the calories crowd into a much smaller pile of food.
Your job is to guess how much of each one 240 calories actually buys. No guides this time.
Within about 40 percent counts as close. That band is a teaching choice, not a measurement. What matters here is the size of the gap between the three, not the decimal.
Three piles, one potato
Each bar is the actual weight of food that 240 calories buys, drawn to scale. The number on the right is how full people said it kept them, against white bread at 100.
Water and fibre weigh a lot and cost nothing in calories. Fry the potato and oil takes the place of the water, so the same calories arrive in a fraction of the food.
Fries and chips are still food, and nobody has to give them up. The point is only that a plate of boiled potatoes and a small handful of chips are the same calories, and they do not land the same.
Fullness is not willpower
Minh does not need a smaller lunch. He needs a lunch that weighs more for the same calories, so three o'clock stops being a fight. Potatoes, oats, eggs, popcorn, fruit, beans. Heavy food, cheap in calories.
Fullness per calorie is not a constant
Foods are not equally filling for the calories they carry. In the study this game is built on, people ate 240 calorie portions of one food at a time and rated their fullness every 15 minutes for two hours. White bread was set at 100 and everything else was scored against it. Boiled potatoes came out at 323 and a croissant at 47, from the same 240 calories.
The study reported that the scores tracked upward with protein, fibre and water content, and downward with fat content and with how good people rated the taste. Those are the honest drivers. Water and fibre are the loudest of them, because they add weight and bulk to a plate without adding calories, which is another way of saying the food has a low calorie density. A boiled potato is mostly water. A potato chip is a potato with the water driven out and oil put in its place.
Read this part before you use any of it
This is one study, published in 1995. Thirty eight foods, groups of 11 to 13 people each, fullness rated over two hours in a lab. That is a small study over a short window. It is not settled physiology, it has not been repeated at scale, it says nothing about what happens across a whole day, and it makes no claim at all about body weight. Nothing in this game promises you will lose anything. What it does show clearly is that equal calorie portions of different foods do not feel equal, and that is useful when you are deciding what goes in the bag.
The arithmetic on screen
Every portion in the game is calculated the same way: 240 divided by the calories per 100 grams, times 100. Calorie figures are USDA FoodData Central, SR Legacy.