Explained: why eating out will ruin your diet

Dining out makes you more likely to give in to temptation and ditch the diet even if healthy food is available, according to a new study co-authored by Professor Lucia Reisch of Cambridge Judge Business School.

We all know how difficult it can be to resist the urge for a sweet treat from the dessert menu or to add “fries with that”, but now a new study published in the journal Social Science and Medicine has examined why eating out can put people’s diets at risk despite their best intentions. 

3 reasons for food choices 

The research finds that food choices away from home are based on:

1. Convenience
2. Taste
3. Speed

This was even the case amongst the health conscious, with healthiness reported as a motivation for only 75 out of 1,458 meals purchased outside the home in the study’s sample. 

“Having a low-effort, fast, and tasty meal seems to frequently emerge in everyday life, undermining the activation of long-term health goals,” the research says. “An overly narrow focus on the present might be further exacerbated by the fact that people reported being more hungry, stressed, and tired when making out-of-home food choices compared to homemade meals.”

Observing real-life food choices – the key to fighting obesity?

Obesity levels are rising globally, and unhealthy diets high in saturated fat and lacking fruit and vegetables are considered a key culprit.

Previous attempts to promote healthier eating have focused on improving individuals’ knowledge and providing detailed nutritional information, but often this approach doesn’t result in lasting change. Public health experts are now increasingly warning about ‘obesogenic environments’, with the ubiquitous exposure to convenient, low-quality food, and social practices and norms around snacking. 

Despite this, there has been little research about people’s food choices in real life. The new study analyses two levels of food decision making: the selection of one food outlet over another, and the choices made within an establishment. It also investigates how some people navigate these tempting environments better than others.

Food habit research shows food purchased away from home was more likely to to be unhealthy

The study focused on adults in Germany, who all had the explicit goal to eat more healthily. Yet 35% of the food they bought away from home was ‘not at all’ in line with their diet goals, compared with only 11% of their homemade meals. Food from cafes, restaurants and even ready-to-eat meals from supermarkets were all logged via a mobile phone app.  

Data was collected over several days, with participants evaluating each eating experience. They recorded their mood (hungry vs. satiated, stressed vs. relaxed) as well as the thought processes behind their selection.  

A seven-point scale was used to assess how healthy and tasty they thought the meal was, and whether the food was in keeping with their dietary goal to eat healthier. If it wasn’t in line there was a follow-up question about whether they thought they ate ‘too much’, ‘too unhealthily’ or ‘unnecessarily.’   

A total of 409 adults took part, with a roughly equal gender split, and a range of academic qualifications. Most meals consumed were homemade, whereas 23% of meals were purchased away from home.

Tasty-sounding food may help those with low self-control

The study found the micro-environment of the café, restaurant, or supermarket itself can affect people’s choices. Often work and public cafeterias can create a ‘lock-in effect’ as their convenient location reduces competition.

For those with low levels of self-control, the research indicates that high availability of healthy food on its own is insufficient for ensuring dietary success. It suggested a simple tool to improve the outcome may be to use attractive dish names that elicit deliciousness and increase the desirability of healthier options.

“We can speculate that people might underestimate the importance of selecting a healthy food outlet or simply overestimate their ability to exercise self-control in the face of delicious but unhealthy food temptations,” says co-author Lucia Reisch, El-Erian Professor of Behavioural Economics & Policy at Cambridge Judge Business School. “A clear way to promote healthier diets is to adapt and carefully design micro-environments, acknowledging the limits of people’s self-control abilities”.

Retailers have a role to play to make healthy options more appealing

The research has policy implications as the presence of appealing, well-promoted healthy food, and ease of selection did reduce the desire in some participants to eat unhealthily. Whereas healthy eating campaigns targeting private households can be seen as government overreach, the study finds targeting cafes, restaurants, and retailers “through a systematic transformation of food environments may be a promising way to increase healthy food choices at scale.”  

This is particularly important as the paper finds people with lower socioeconomic status typically have an “absence of healthy and affordable food outlets that can be reached easily and fast. This constitutes an additional burden, particularly for vulnerable and less mobile people which increases unhealthy food consumption and reinforces existing health inequalities.”

Monitoring food likely to contribute to healthier choices

The authors recognise the limitations of the findings as participants’ assessment of the environment and healthiness of food choices were subjective. They also found that meals and snacks became healthier as the study went on, suggesting that the act of monitoring was contributing to success. While this survey focused on those wanting to improve their diet, the authors recommend future research should assess those without a healthy eating goal to be more representative of the population.