Is Fat Killing You, or Is Sugar?
What we do and don’t know about dietary science.
Read the full article at: www.newyorker.com
What the scientific studies fail to account for is the effect of sugar and fat on appetite and satiety.
Everyone has had the experience of enjoying their favorite meal until they are so full that they can’t take another bite. Then, suddenly, by some miracle of physics an empty space in their stomach opens up precisely when they see the pecan pie rolled out on the dessert cart. This is no mystery. Scientific principles such as sensory specific satiety, dynamic contrast, and the food pleasure equation allow us to always make room for dessert and also allow us to eat a lot more low caloric density food, such as sugar and processed carbohydrates, than fat.
The other important component missing from the scientific data is subjective satiety. We all know what it feels like to be famished and to be full, but what about all the intermediate stages of hunger? If you eat slowly enough and pay close enough attention, you will notice several stages of satiety:
- You eat enough to just take the edge off your hunger
- No longer hungry but not feeling full either
- The beginnings of stomach pressure
- Feeling of fullness throughout the abdominal cavity
- Belt tightening
- Fullness affecting the respiratory system (hiccups, shallow breathing, etc. to accommodate abdominal expansion)
- Regurgitation and nausea
The Japanese expression “Hara Hachi Bu” describes the practice of eating until you are 80% full. Most of us have no idea what this feels like. Mindless eating is only partly to blame. It takes a good 15 to 20 minutes for satiety signals to reach the brain, and junk food is engineered to suppress or bypass these signals with vanishing caloric density and taste hedonics, among other tricks.
The bottom line is that healthy fats (mono-unsaturated, like almonds, olives, and avocados) will keep you satisfied longer, while sugar will make you hungry and increases your threshold for sweets. So it’s not a question of which is worse for you, but rather which one makes you eat more, and sugar is clearly the primary offender.