Obese people less likely to consider their next meal when considering portion sizes

Choosing what we eat, how much we eat and when we eat comes with many conflicting pressures and consequences. As a result, making healthy decisions is often difficult and obesity continues to be a serious health problem in Europe, with almost 1 adult in 6 in the EU and over 20 % in the UK being classed as obese (Eurostat).

Many components influence poor food choices from cultural, social, cognitive and familial to genetic and epigenetic traits. Thanks to a study crafted by the University of Bristol, a NUDGE-IT consortium member, researchers have now discovered another strong trait. Individuals with a high Body Mass Index (BMI) i.e. of 30 or over, tend to ignore when their next meal is likely to take place when selecting their portion sizes whilst on the contrary, those with a lower BMI tend to acknowledge their next meal times. ‘Meal timings and future planning are an important area of research in obesity. These findings are exciting because they are the first to demonstrate that discounting operates in planning from one meal to the next and that people with obesity might not be factoring that into their choices’, shared Annie Zimmerman, a doctoral student and lead author of the study.

In the past, psychologists examined ‘delay discounting’ - the tendency to treat something as less significant based on how far in the future it will occur - in tasks focusing on money. However, for the first time here, researchers have assessed how people classed as obese ‘delay discount’ information about future meal timing, thus showing signs of impulsivity and overlooking future rewards or consequences.

Participants were asked to take part in a series of computerised tasks, including choosing portion sizes after being told how long after lunch their next meal would be (ranging up to 8 hours later). ‘Our results are consistent with the idea that overeating is promoted by feeling in the moment, disregarding future consequences of decisions. This novel finding might help to explain why being overweight is associated with irregular meal timings. Potentially there could be targeted interventions for obesity to promote future thinking in meal planning,’ underlined Zimmerman.

Such results indeed bring much food for thought when trying to better understand the decision-making processes behind our food choices. In a world where food-related disorders, such as obesity, are on the rise and many factors guide our choices, developing appropriate healthy eating policy making models have become all the more important.

Nevertheless, despite bringing a better understanding of the factors that drive food choice, ‘to fully understand the role of dietary discounting in eating behaviours and the links to obesity we need to develop a multifaceted model of discounting,’ explained Zimmerman.

The NUDGE-IT project, which runs until December 2018, has received just under EUR 9 million and engages internationally with leading experts across various disciplines to develop innovative tools, better understand decision-making in food choice and build predictive models to improving public health policy.

For more information, please see:
project website