Full of Hunger
“I’m full of rice, but I’m hungry for cake.”
How many of us can relate to this sentence? Many a parent has heard a child utter something similar and all adults have had similar feelings, even if we may not voice them.
There are three components to an eating behavior. Sometimes, eating starts with feeling hungry, which can manifest as a sense of emptiness in the stomach, “growling” sounds and sensations in the abdomen and a craving for food. This can initiate eating, but eating can also be stimulated by sight, smell or craving for a specific taste without hunger.
As you start to eat, you begin to feel satiation. Satiation is what stops you from continuing to eat. When you have reached satiation your eating will stop.
This starts the period of satiety. Satiety is how full you feel for how long. In other words, a food with a high satiety will keep you from eating for a prolonged period after an eating episode.
The researcher who has taken the most intense look at this issue of satiety is Susanna Holt at the University of Sydney in Australia. Her lab has developed a list of foods called the satiety index. What this index shows is how effective a food was at curtailing eating behavior after you ate a standardized number of calories of that food.
On average, fruit was the most satisfying type of food, but there was high variability. There was one consistent finding, however.
Fatty foods were the least satisfying category.
In 2005, Dr. Holt did another study and she states the following:
We've just done a short study comparing the satisfying power of different breakfasts. Two high-fat breakfasts of fried eggs and bacon and toast or croissants and jam were much less filling than two equal-calorie high-carb breakfasts which were either rapidly-digested (cornflakes with sugar and toast and jam) or slowly-digested (All-Bran with banana slices, toast and margarine).
So in a case of adding injury to insult, the foods that give us the most calories are also the least effective at stopping us from eating. Think about that next time someone tells you that fat doesn’t make you fat.
What was the most satisfying single food?
Good old white russet potatoes at that. Their satiety index is 332. To compare, white bread is 100, a donut is 68, jellybeans are 118, oatmeal is 209, beef is 176 but oranges are 202. Unrefined fruits and starches on average have the best scores, whereas processed and refined foods score low along with fatty foods.
Looking at the whole list, what jumps out is how bad snack foods and desserts are at making someone feel full. One of the most successful choices people can make for their health is to give up commercial snack foods and desserts and replace them with things like carrots or apples.
In the long run, the best health is going to come to those whose food intake satisfies hunger without leading to calorie overconsumption. Whole plant foods have the best track record and fatty foods, snacks and desserts the worst.