Craving answers to our food cravings
I often find myself “craving” certain foods and doubt that I’m the only one. In fact, nearly 100% of women and 70% of men surveyed report the same thing. When we get a craving, we experience an intense urge to consume a specific food and may even go out of our way to obtain this food. In this way, craving is different from both hunger (when we desire any type of food) and liking a food (which is far less intense). But why do we have food cravings? Here are some of the theories...
A nutritional deficiency?
A common belief is that we crave certain foods because our diets are deficient in essential nutrients or calories. Many women, for example, crave dairy products while they are pregnant. Since dairy is high in calcium, which promotes strong bones, this craving could serve to be beneficial to both mother and foetus. Yet, this theory does not seem to line up with scientific studies done both in and out of the lab, which show that individuals with nutritionally adequate diets still experience food cravings (Pelchat, 2004).
Chocolate is one of the most frequent foods to be associated with cravings and is believed to be so because of the “mood-elevating” properties of cocoa. Yet once again, findings from laboratory studies suggest differently. In one such experiment, subjects who craved chocolate were given cocoa-containing capsules or a chocolate bar to test whether either of these reduced their cravings (Yanovski, 2003). Importantly, only the participants given the chocolate itself found their chocolate cravings were satisfied.
An evolutionary trait?
One less easily tested theory is that food craving, particularly for calorie or “energy-dense” foods, is a leftover trait that our ancestors evolved in ancient times (Lowe, 2013). Back when food was scarce (and had to be caught rather than bought), the energy required to obtain a particular food needed to be offset by the energy gained through eating the food. Logically, this would mean that high carb foods offered the best chance of ensuring survival for our ancestors. Unfortunately, such food types are no longer scarce these days or difficult to obtain, leading to problems with obesity.
A “higher order” process?
The prefrontal cortex is an area of our brains known to perform a number of higher order cognitive functions, including self regulation. Many scientists now believe that this control may extend to our dietary habits, in particular our food cravings. In brain imaging experiments, individuals that exhibit greater self control when offered their favourite foods, show increased activity in the dorsolateral prefrontal cortex in comparison to their “less controlled” counterparts (Lowe, 2013). Could cravings stem from a lack of activity in this region of our brains?
Still craving answers
These theories (and many others) have been put forward to try and explain why we crave certain foods; some with more scientific backing than others. I’ll leave it to you to decide which of these you favour...
Pelchat ML, Johnson A, Chan R, et al. 2004. NeuroImage. 23: 1486-1493.
Yanovski S. 2003. Sugar and fat: cravings and aversions. Journal of Nutrition. 133: 835S-837S.
Lowe C, Hall P. 2013. Neurobiological facets of food craving and consumption: evidence from neuropsychological and transcranial magnetic stimulation (TMS) studies. Social Neuroscience and Public Health. 303-314.