Your Brain On Junk Food

Notes for James Clear’s post: What Happens to Your Brain When You Eat Junk Food:

Conventional reasons not to eat junk food.

  • Heart problems / high blood pressure
  • Linked to depression
  • Obesity

Food factors that overcome those known cons.

Summarizes Steven Witherly’s work (a food scientist) on why we like certain foods.

  • Sensation of eating the food. How well are the taste qualities stimulated, the smell of the food, as well as the texture.
  • Nutrient composition of the food. Combinations of salt / sugar / fat.

Engineering food.

  • Evoking multiple different sensations with the food. For example, french fries, are crunchy at first, but then make a paste-like texture before ingestion.

  • Salivary gland stimulation. Foods that cause saliva to be released are more effective in delivering active tastants to the taste buds of the oral cavity.

  • Fast removal of oral stimulation. If you can clear food signals, the brain can be tricked to believing it has not consumed enough food. Cheetos are a good example:

    “It’s called vanishing caloric density,” Witherly said. “If something melts down quickly, your brain thinks that there’s no calories in it . . . you can just keep eating it forever.”

  • Avoiding sensory desensitization. Prolonged exposure to a ligand, or mechanical stimulation can desensitize receptors and hence your ability to report the presence of that ligand. Junk food is designed to prevent this.

  • Calorie density. Junk food has an optimal energy density to prevent the brain from feeling sated.

  • Reliable conditioning stimuli. The smell, or sight of a familiar food will activate the memories of prior taste experiences. Advertising, the packaging, and the smells can all re-evoke your memories.

Steps to avoid junk food.

  • Environmental programming. You can’t eat what you don’t stock in your refrigerator. Avoid junk food in groceries, which tend to be in the middle of the grocery.

  • Choose variety for meals. You can perform the same multi-stimulation trick by choosing several healthy foods for a meal.

  • Stress may reduce your willpower to eat healthy food. Acknowledge this and try to find other means to cope with stress.