A food craving is an intense desire to consume a specific food, and is different from normal hunger. It may or may not be related to specific hunger, the drive to consume particular nutrients that is well-studied in animals. In studies of food cravings, chocolate and chocolate confectioneries almost always top the list of foods people say they crave; this craving is referred to as chocoholism.
There is no single explanation for food cravings, and explanations range from low serotonin levels affecting the brain centers for appetite to production of endorphins as a result of consuming fats and carbohydrates. Foods with high levels of sugar glucose, such as chocolate, are more frequently craved than foods with lower sugar glucose, such as broccoli because when glucose interacts with opioid system in the brain an addictive[medical citation needed] triggering effect occurs. The consumer of the glucose feels the urge to consume more glucose, much like an alcoholic, because the brain has become conditioned to release "happy hormones" every time glucose is present. There is evidence that addiction and food craving activate some of the same brain areas. Specifically, when smokers look at pictures of people smoking it activates the same areas of the brain as when obese people look at pictures of food.
The cravings for certain types of food are linked to their ingredients. Chocolate for example, contains the amino acid phenylethylamine, which is important for the regulation of the body’s release of endorphins. Endorphins are released following a stressor and result in a sense of relaxation. Exercise and sleep are two alternative ways to help facilitate the release of endorphins.
Chocolate also contains large quantities of iron, which can be depleted during the menstrual cycle. Another common craving is salt. Craving salt may be partly due to being dehydrated. When dehydrated the body loses water, electrolytes, and salt, and by ingesting salt, water retention can be increased. Craving salt can also be a sign of diabetes, heart disease, and sickle cell anemia.
Carbohydrates, or particularly sugars, are yet another common craving. These cravings occur often in the middle of the afternoon when energy is at its lowest.
The craving of non-food items as food is called pica.
Theories claim that many of the cravings women sometimes have for strange foods during pregnancy can be attributed to important nutrients that are required during that specific period. One of the treatments for morning sickness consists in accommodating food cravings and aversions. Research is being conducted to determine the mechanism behind food cravings during pregnancy.
Depending from the historical period and the culture there are different traditions regarding pregnancy cravings. Some examples are:
- During pregnancy Hmong women would follow their food cravings to guarantee that their child would not be born with a deformity. 
- In Malta pregnant women are encouraged to satisfy their cravings for specific foods, out of fear that their unborn child will bear a representational birth mark (Maltese: xewqa, literally "desire" or "craving").
- In the Babylonian Talmud, Chapter 82a of Tractate Yoma mentions pregnancy cravings for non-kosher food (the passage discusses a pregnant woman who craves pork on Yom Kippur) as the paradigmatic example of a presumed life-threatening situation where a person is allowed to eat non-kosher food (and is permitted to eat it on Yom Kippur).
- In Thailand a woman who starts craving sour foods after her period has stopped is deemed to be pregnant.
- Ronzio, Robert A. (2003). "Craving". The Encyclopedia of Nutrition and Good Health (2nd ed.). Facts on File. p. 176. ISBN 0-8160-4966-1.
- Carr, Tanya; Descheemaker, Koen. "Food cravings and addictions - fact and fallacy, by Peter Rogers". Nutrition and Health - Current topics - 3 (Antwerp ed.). Garant. p. 69. ISBN 90-441-1493-X.
- Yanovski, Susan. "Sugar and Fat: Cravings and Aversions". The Journal of Nutrition.
- Noll, Eric, Wendy, and Brundige. "The Science of Food Cravings". ABC News Network. ABC News Network. Retrieved 05/06/2013. Check date values in:
- Musgrove, Rebekah. |work=Women’s Health Issues "The Science Behind Food Cravings". Women's Health Issues. Women's Health Magazine. Retrieved 05/06/2013. Check date values in:
- Rokade, Dr. P.B. "Release of Endomorphine Hormone and Its Effects on Our Body and Moods: A Review". International Conference on Chemical, Biological and Environmental Sciences. Dr. P.B. Retrieved 05/06/2013. Check date values in:
- Cantoni, P., Hudson, R., Distel, H. and Laska, M. (1999) Changes in olfactory perception and dietary habits in the course of pregnancy: a questionnaire study. Chem. Senses, 24, 58.
- Fadiman, Anne. The Spirit Catches You and You Fall Down: A Hmong Child, Her American Doctors, and the Collision of Two Cultures. New York: Farrar, Straus and Giroux 1997:5
- "Liamputtong, P., Yimyam, S., Parisunyakul, S., Baosoung, C., & Sansiriphun, N. (2005). Traditional beliefs about pregnancy and child birth among women from Chiang Mai, Northern Thailand. Midwifery, 21(2), 139-153. Retrieved from EBSCOhost on 04/15/2011.