The Calorie Conundrum

Obesity is a global problem, despite the level of health information available to us never having been so high. We know that foods high in fat and sugar content are bad for us, but we just can’t seem to resist that nice juicy burger or the last slice of cheesecake! And there’s a very good reason for this. Foods such as these would have been invaluable to our hunter-gatherer ancestors as a source of energy to help them survive in an environment way more hostile than the world we live in today. Our brains are ‘hard-wired’ to desire such foods, even though they have become maladaptive today.

One trick to overcome this evolved bias involves moving us from what we might call a ‘mindless’ state to a more ‘mindful’ one. By an large, unconscious biases only work if they remain unconscious, so getting someone to stop and think is a very effective way of encouraging a healthier choice. That’s the logic behind policy interventions designed to promote the provision of nutritional information, especially calorie counts, and it’s a strategy that’s fast becoming a legal requirement in many territories. Problem is that the evidence on whether such interventions actually work is rather mixed. Some studies suggest that displaying calorie information on a menu or product label can reduce calorific intake by up to 45%, while other studies have found it makes no difference whatsoever.

A recent study by Steven Dallas and his colleagues offers an important insight into why the results to date have been so contradictory. Approaching the problem from an information-processing perspective, rather than an information content one, Dallas et al suggest that the crucial factor is probably where the calorie count is displayed, rather than what is displayed. In an interesting series of experiments, the researchers found that placing the calorie data to the right of the food name on a restaurant menu had no impact whatsoever on the items diners ordered and their overall calorie intake, whereas displaying the calorie data before the item name reduced intake by over 16%.

The most likely explanation for this apparent left-right intake is probably to do with the way the brain processes language information. Reading the name of a tempting dish and then seeing its calorie content is less effective because the unconscious emotional associations surrounding a high-value food have already begun their work. When we see the calorie information before the dish name and description, however, we are more likely to be jolted into that necessary mindful state and the unconscious biases can be overcome. In other words, it’s all to do with the order in which we read the information, an effect confirmed when Dallas et al obtained the exact opposite results from Hebrew-speakers who, of course, read from right-to-left and process the information accordingly.

The lesson here is very simple. The evolutionary bias at the heart of the obesity problem is very strong and displaying calorie counts can certainly help overcome it.  However, we need to be less hung up about what information is provided and how prominent the font is (within reason) and focus on the much simpler solution of adopting a calorie-product presentation sequence instead.