Read the following paragraph and underline the topic sentence.
You're not the only one who could eat up a bag of chips in one sitting. The reason you keep dipping your fingers back into the chip bag has more to do with salt than with fat. Normally, fat helps make a meal more satisfying as it provides high calories, so people don't want to just keep eating and eating. However, eating salt triggers the release of dopamine(多巴胺), a chemical substance that controls your brain's pleasure center. Once your brain gets that first reward hit, it starts wanting more. When food is low in salt, it's easy to practice self-control instead of overeating, but when you add salt to that food, all of a sudden, those controls are gone.
The reason you keep dipping your fingers back into the chip bag has more to do with salt than with fat.
