An article by Dr. Aaron Neufeld from the Los Altos Optometric Group showed that there are three types of tears: Basal, Reflex, and Psychic. Psychic tears are associated with emotions and it is linked to hormones that heighten the cortisol level. Cortisol is a hormone that we released when we’re stressed. Cortisol has many functions like regulating our metabolism, controlling blood sugar, and reducing inflammation. Cortisol plays a huge role in our cravings and contribute to weight loss as a result of the stress hormones released. Previously, biochemist William Frey in 1982 also reported the same fact that crying could help remove toxic substances that build up due to stress.
In the International Journal of Obesity, there is a study titled 'Energy Expenditure of Genuine Laughter.' The study recruited 31 males and 63 females aged 18–34 years. In short, the participants are asked to watch several videos that can emotionally impact them. While the participants observed the videos, the researchers measured the impact of emotions on the body using a special tool. The study found that laughing and crying are estimated to burn approximately 1.3 calories per minute from the participants' responses.
But to go further, researchers say weight loss caused by sadness and depression is more closely related to loss of appetite than crying.