Gimme Sugar: The Creation of Cravings

Can't ignore that craving? Chances are the sweet treat you're daydreaming about has been engineered to make it as difficult to give up as possible. A trainee nutritionist explains

Feature by Alicia Wooding | 12 Aug 2014

For me, it’s chocolate. There’s something about chocolate that means I don’t seem to be able to get though a week without it – and the minute I decide that I’m cutting back, the cravings creep in. That overwhelming urge to devour the item of fixation. As a nutritionist (to be) with a degree in psychology, you might think I’d have a rational thought process to overcome desires for unhealthy treats. But I’m not sure there is an easy way to ignore cravings. Let me explain.

Normally, our bodies are very clever at regulating food consumption. We feel hungry when our stomach is empty, or blood sugar levels are low and a hormone called ghrelin is released to tell the brain to look for food. But we don’t always eat out of necessity; sometimes it’s purely a gastronomic indulgence. Eating is enjoyable because there are areas in the brain that are stimulated by the sight, smell and taste of food, and release hormones (such as dopamine) that make us feel good. Scientists refer to these areas as 'reward circuits', because the hormonal release encourages us to repeat the pleasurable behaviour – forming a feel-good feedback loop.

Interestingly, these brain areas have also been shown to be involved in drug addiction. Professor Paul Kenny, a neuroscientist at The Scripps Research Institute in Florida, has published several papers on how food influences the reward circuitry of the brain. He claims that overeating 'highly palatable' foods causes brain activation similar to what is seen during drug use – and of those highly palatable foodstuffs, the most addictive in his studies were high in both fat and sugar. His lab rats even endured electric shock to carry on eating their tasty morsels instead of moving to the danger-free zone, showing just how powerful the pleasure of food can be in overriding our sense of judgement. Cravings feed on these hedonistic brain mechanisms, compelling us to seek out a certain food because we can anticipate its associated pleasure.

Chocolate, then, ranks so highly on the craving scale as it is one of these highly palatable blends of sugar (glucose) and fat. Glucose is absorbed into the blood, quickly giving the brain a fast energy buzz, and the addition of fat creates the creamy texture that makes chocolate feel so good to eat. This combination is not present in natural foods, so the brain gets overwhelmed with excitement and encourages us to seek the experience again.

Food manufacturers put a lot of effort into exploiting cravings. Endless research goes into perfecting the sensory experience of foods to make consumers desire them. Michael Moss, a journalist at the New York Times, spent years digging behind the scenes at major food corporations to find out how they capture the sensory pleasures we seek. From the crunch of crisps to the bliss of melting chocolate, food scientists have tweaked their creations to perfection. This explains why we are far more likely to crave manufactured foods (like crisps) than their natural derivatives (potatoes); they have been designed to deliver immediate gratification with optimised texture and flavour combinations.

Despite all this, there are some odd cravings that can’t be explained by palatability. For example, during pregnancy women sometimes experience 'pica' – an appetite for non-nutritious items such as ice, but also inedible substances like coal. In these cases, it seems that the texture or 'mouthfeel' of the items may be driving the craving. The condition is pretty baffling, even to doctors, but may be linked to chemical or neurological imbalances during pregnancy.

The overwhelming, and sometimes confusing, nature of cravings suggests they could have stemmed from an evolutionary mechanism driving us to seek specific foods in times of need. But as our access to a variety of food has increased considerably, modern cravings are likely to be working on purely pleasure principles. Humans are pleasure seekers, and food is, for those of us in more fortunate situations, one of the easiest pleasures to access (perhaps too pleasurable and easy). Ultimately, it’s hard to ignore cravings because they feed off our most powerful drivers: the need for food, and the desire for pleasure.

Of course, a little of what you fancy can be satisfying within a balanced diet – if you remember your greens in abundance and your cakes in moderation, occasionally indulging cravings is fine. Just maybe avoid that extreme end of gnawing on coal...

Professor Paul Kenny’s research: www.scientificamerican.com/article/is-obesity-an-addiction

Kenny, PJ: Common cellular and molecular mechanisms in obesity and drug addiction, Nature Reviews Neuroscience (2011) Oct 20;12(11):638-51

Michael Moss research: Salt, Sugar, Fat: How the Food Giants Hooked Us (WH Allen Publishers, 2014)

More info:

Volkow ND, Wang GJ, Baler RD: Reward, dopamine and the control of food intake: implications for obesity, Trends Cognitive Sciences (2011);15(1):37-46

Cepeda-Benito A, Gleaves DH, Williams TL, Erath SA: The development and validation of the State and Trait Food-Cravings Questionnaires, Behavior Therapy (2000); 31:151–173