1. Melt in your mouth effect

Many candies such as chocolate bars and cotton candy have this effect. When the food touches your tongue, the melting-in-your mouth sensation makes it feel like you are eating something lightweight. Your brain believes you are not eating enough and causes you to eat more than you should. Many companies that sell unhealthy snacks consider the texture of their foods. For example, chocolate companies spend a lot of their time testing the shape of their chocolate because certain shapes and textures can leave a better impression on the consumer.

2. Stress

School can be stressful to many, especially towards the end of the quarter. You may feel like you are craving unhealthier food. When you are under a lot of stress, your body wants more sugars and carbohydrates to help you get through hard times. Stress can cause your body to elevate your levels of cortisol, a hormone which helps relieve stress. Elevated levels can cause you to want salty and sugary foods.

3. Dynamic contrast

Common junk foods have different types of textures and many of them contrast with each other. For example, sweet and salty, sour and sweet and crunchy and smooth. Your brain enjoys the different tastes and textures, which makes you crave them more.

4. Salivation

Sometimes you may catch yourself almost drooling over the thought of eating your favorite foods. Salivation is used to cover a larger amount of space on your tongue with the flavors from the food you are eating. The more you salivate, the more the flavors will reach around your tongue. Foods that promote salivation are dressings, sauces, ice cream and chocolate.

5. Memories

Thinking about previous times you have eaten some can cause you to crave particular foods. When you eat food, your brain remembers the senses as you ate the food. The texture, taste, smell and situation you were in. Advertisers use this to their advantage and produce foods and snacks that will be easily remembered, such as the powdery doughnut sugar left on your fingers or the smell of buttery popcorn at the movies.