Calorie-Quality Factor 1: Satiety
A calorie is not a calorie when it comes to filling us up and keeping us full. Ever notice how a six-pack of beer makes people eat more pizza while five cans of tuna or thirty cups of broccoli—the same quantity of calories—would make them uncomfortably full? The capacity of calories to make us and keep us full is called Satiety. The fewer calories needed to fill us up and the longer those calories keep us full, the higher the Satiety value of the food. The first measure of assessing the SANEity of a food is its Satiety.
A study published in the Annals of Internal Medicine followed ten obese patients with type 2 diabetes for twenty-one days, and found that the people who ate as much high-Satiety protein and natural fat as they wanted, while avoiding low-Satiety starches and sweets, unconsciously avoided 1,000 low-quality calories per day.68 These participants then reported feeling as satisfied as other people in the study who ate 1,000 more lower-Satiety calories.
Why is eating 1,000 fewer low-quality calories per day useful? Didn’t we just show how harmful starvation is? Yes, but we’re not talking starvation here. When we eat high-Satiety food, we take in more food and much more nutrition, but unintentionally become full faster, stay full longer, and therefore automatically avoid overeating. More food, more nutrition, more energy, and unconsciously avoiding excessive calories is entirely different from less food, less nutrition, feeling hungry, and being tired and cranky all day. The surplus of nutrition and satisfaction from high-satiety food saves us from the side effects of starvation.
The primary areas in our brain influenced by high-Satiety food are the lateral hypothalamus and ventromedial hypothalamus. They tell us when we feel satisfied from eating. Their “you are satisfied” signals that tell us to stop eating are dependent on three factors:
1. How much do the calories we are eating stretch our digestive organs?
2. How much do the calories we are eating affect short-term Satiety hormones?
3. How much do the calories we are eating stimulate long-term Satiety hormones?
We can eat more high-Satiety food by focusing on foods that contain high amounts of water, fiber, and protein.* How much any given food stretches our stomach and other digestive organs is mostly determined by the amount of water and fiber in it. More water and fiber means bigger food, more stretch, and getting fuller and staying fuller longer. That is why 200 calories of wet, fibrous celery is more filling than 200 calories of dry, fiber-free gummy bears. Calorie for calorie, celery is about thirty times the size of gummy bears, stretches our stomach and other digestive organs much more, and is therefore much more satisfying.
The amount of protein that food contains is also important. Harvard researchers have found that the amount of protein in food affects the other two factors that influence whether our brain is telling us we are hungry or full: short- and long-term Satiety hormones. More calories from protein mean more “full” hormonal signals being sent to our brain.
These scientific findings have been repeated in numerous clinical trials:
In a University of Washington study, participants ate an unlimited quantity of calories while having the proportion of protein in their diet increased from 15 percent to 30 percent. They responded by unconsciously avoiding 441 excess calories per day without feeling hungry.69
In a University of Sussex study, participants ate either a high-protein or a low-protein meal. The high-protein people unconsciously ate 26 percent less than the low-protein people at their next meal without feeling hungry.70
In a University of Leeds study, participants ate the exact same weight of food, but one group ate a higher percent from protein. The higher-protein group unconsciously ate at least 19 percent fewer calories than the lower-protein group without feeling hungry.71
In a Karolinska Hospital study, participants ate more or less protein for lunch. The more-protein group got full on 12 percent fewer calories at dinner than the less-protein group.72
The science is clear: More water, fiber, and protein mean more Satiety. More Satiety means we are too full for set-point-raising low-quality food.