̽��ֱ�� of Cambridge - food choices

Fish bellies, fava beans and food security

plc32 — Fri, 05 Apr 2024 15:20:27 +0000

Cambridge Zero and Cambridge Global Food Security gather academics and experts to share solutions for the planet’s looming food production problem.

Messaging on healthy foods may not prompt healthier purchases: study

Anonymous — Tue, 28 Jun 2022 09:37:31 +0000

People making food-buying choices are often faced with adverts or other descriptions such as ‘low calorie’ (healthy) or ‘tasty’ (less healthy) to influence their decisions, so how effective are health-conscious nudges in moving consumer behaviour toward healthier lifestyles?

A study published in the journal Appetite finds that healthy cues standing alone have, surprisingly, little impact in prompting more healthy buying decisions, while ’hedonic‘ or pleasure-linked cues reduce healthy choices by 3%.

When healthy and non-healthy prompts are presented at the same time, however, the healthy prompts had a protective effect in fully neutralising the non-healthy nudges, perhaps by triggering an ’alarm bell’ to activate control processes.

̽��ֱ��study was based on 1,200 Dutch participants and the sample was selected to be representative of age, gender, and income for the Netherlands.

̽��ֱ��study fills some important gaps in understanding how these cues affect food-buying choices. Previous studies had largely been based on small samples and narrow populations (such as university students), and were based on healthy messages standing alone rather than alongside non-healthy cues.

“ ̽��ֱ��practical impacts of our findings are two-fold: the results cast doubt on the effectiveness of health-goal cues to boost healthy food choices, but they suggest that healthy primes could prevent less healthy food choices by countering hedonic cues through the interaction of the competing messages,” said co-author Lucia Reisch, El-Erian Professor of Behavioural Economics & Policy and Director of the El-Erian Institute of Behavioural Economics & Policy at Cambridge Judge Business School.

̽��ֱ��results were largely unaffected by factors including gender, hunger, dietary restraint and body mass index. ̽��ֱ��study’s methodology mimicked an online supermarket, and presented the competing healthy and hedonic cues through advertising banners for cooking recipes – which contained texts including such phrases as ‘healthy’ or ‘low in calories’ (with images of low-caloric meals such as a quinoa salad), and ‘just delightful’ or ‘heavenly enjoyment’ (with photos of tempting foods high in fat or sugar such as an apple tart). To test healthy or non-healthy messages standing alone, the impact on choice was compared with advertising banners unrelated to food such as tissues.

Participants made 18 choices through the mock supermarket, each time selecting one product out of six alternatives (three healthy and three not) through a mouse click.

Based on previous knowledge of health-goal priming effects, the researchers had hypothesised that health goal cues would result in more healthy food choices.

“Our results do not support this hypothesis,” the study says. “Given the high statistical power of the current study, our observed null effect cast some doubt on the generalisability of the frequent positive findings of health goal priming to the population level.” ̽��ֱ��research did find that the placement of the advertising banners mattered, with more healthy choices resulting when the healthy prime was in the top position rather than a lower position.

“From a public health perspective, the fact that we used very similar stimuli to change behaviour through a health and a hedonic prime but only managed to reduce healthy choices compared to neutral control is relevant,” concludes the study, which uses the term ‘prime’ to describe cues or nudges.

“If it is, all else equal, easier to activate hedonic goals through environmental cues, public health campaigns will be at a technical disadvantage compared to efforts through food advertisement and marketing campaigns. Further research should replicate our findings to test whether the observed differences between health and hedonic goals were linked to our specific experimental design or are universal.”

Reference:
Jan M.Bauer et al. 'Battle of the primes – ̽��ֱ��effect and interplay of health and hedonic primes on food choice.' Appetite (2022). DOI: 10.1016/j.appet.2022.105956

Originally published on the Cambridge Judge Business School website.

Healthy food cues standing alone don’t prompt healthier buying decisions, but they may counter advertising for sugary and fatty foods, says study co-authored by Cambridge researchers.

Franki Chamaki via Unsplash

Supermarket aisle

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. Images, including our videos, are Copyright © ̽��ֱ�� of Cambridge and licensors/contributors as identified. All rights reserved. We make our image and video content available in a number of ways – as here, on our main website under its Terms and conditions, and on a range of channels including social media that permit your use and sharing of our content under their respective Terms.

Yes

New evidence suggests nutritional labelling on menus may reduce our calorie intake

cjb250 — Tue, 27 Feb 2018 00:21:43 +0000

Eating too many calories contributes to people becoming overweight and increases the risks of heart disease, diabetes and many cancers, which are among the leading causes of poor health and premature death.

Several studies have looked at whether putting nutritional labels on food and non-alcoholic drinks might have an impact on their purchasing or consumption, but their findings have been mixed. Now, a team of Cochrane researchers has brought together the results of studies evaluating the effects of nutritional labels on purchasing and consumption in a systematic review.

̽��ֱ��team reviewed the evidence to establish whether and by how much nutritional labels on food or non-alcoholic drinks affect the amount of food or drink people choose, buy, eat or drink. They considered studies in which the labels had to include information on the nutritional or calorie content of the food or drink. They excluded those including only logos (e.g. ticks or stars), or interpretative colours (e.g. ‘traffic light’ labelling) to indicate healthier and unhealthier foods. In total, the researchers included evidence from 28 studies, of which 11 assessed the impact of nutritional labelling on purchasing and 17 assessed the impact of labelling on consumption.

̽��ֱ��team combined results from three studies where calorie labels were added to menus or put next to food in restaurants, coffee shops and cafeterias. For a typical lunch with an intake of 600 calories, such as a slice of pizza and a soft drink, labelling may reduce the energy content of food purchased by about 8% (48 calories). ̽��ֱ��authors judged the studies to have potential flaws that could have biased the results.

Combining results from eight studies carried out in artificial or laboratory settings could not show with certainty whether adding labels would have an impact on calories consumed. However, when the studies with potential flaws in their methods were removed, the three remaining studies showed that such labels could reduce calories consumed by about 12% per meal. ̽��ֱ��team noted that there was still some uncertainty around this effect and that further well conducted studies are needed to establish the size of the effect with more precision.

̽��ֱ��Review’s lead author, Professor Theresa Marteau, Director of the Behaviour and Health Research Unit at the ̽��ֱ�� of Cambridge, UK, says: “This evidence suggests that using nutritional labelling could help reduce calorie intake and make a useful impact as part of a wider set of measures aimed at tackling obesity,” She added, “There is no ‘magic bullet’ to solve the obesity problem, so while calorie labelling may help, other measures to reduce calorie intake are also needed.”

Author, Professor Susan Jebb from the ̽��ֱ�� of Oxford commented: “Some outlets are already providing calorie information to help customers make informed choices about what to purchase. This review should provide policymakers with the confidence to introduce measures to encourage or even require calorie labelling on menus and next to food and non-alcoholic drinks in coffee shops, cafeterias and restaurants.”

̽��ֱ��researchers were unable to reach firm conclusions about the effect of labelling on calories purchased from grocery stores or vending machines because of the limited evidence available. They also added that future research would also benefit from a more diverse consideration of the possible wider impacts of nutritional labelling including impacts on those producing and selling food, as well as consumers.

Professor Ian Caterson, President of the World Obesity Federation, commented: “Energy labelling has been shown to be effective: people see it and read it and there is a resulting decrease in calories purchased. This is very useful to know – combined with a suite of other interventions, such changes will help slow and eventually turnaround the continuing rise in body weight.”

Reference
Crockett RA, et al. Nutritional labelling for healthier food or non-alcoholic drink purchasing and consumption. Cochrane Database of Systematic Reviews 2018, Issue 2. Art. No.: CD009315.

New evidence published in the Cochrane Library today shows that adding calorie labels to menus and next to food in restaurants, coffee shops and cafeterias, could reduce the calories that people consume, although the quality of evidence is low.

There is no ‘magic bullet’ to solve the obesity problem, so while calorie labelling may help, other measures to reduce calorie intake are also needed

Theresa Marteau

Michael Stern

Wall_Food_10087

Making sense of our unhealthy behaviour

Professor Marteau will be speaking at the 2018 Cambridge Science Festival about why we sometimes make 'unhealthy' choices and how we might encourage people to change.

Friday 16 March: 5:30pm - 6:30pm

Babbage Lecture Theatre, New Museums Site Downing Street, CB2 3RS

Details and how to book here.

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution-ShareAlike

Chicken korma, Eton mess and a genetic variant provide clues to our food choices

cjb250 — Tue, 04 Oct 2016 14:24:12 +0000

̽��ֱ��research has provided insights into why we make particular food choices, with potential implications for our understanding of obesity. This is one of the first studies to show a direct link between food preference and specific genetic variants in humans.

Most people find high fat, high sugar foods particularly appetising. This can lead to eating more calories than we need and can contribute to weight gain. But what influences food choice? ̽��ֱ��taste, appearance, smell and texture of food are all important, but biology may also play an important role.

Previous studies in mice have shown that disruption of a particular pathway in the brain involving the melanocortin-4 receptor (MC4R) can lead to mice eating a lot more fat. Unusually, these mice eat a lot less sugar. However, the relevance of these findings to eating behaviour in people has been unclear until now.

In a study published today in the journal Nature Communications, researchers at the ̽��ֱ�� of Cambridge gave participants an all-you-can-eat buffet of chicken korma – a popular type of curry – with three options manipulated to look and taste the same, but in which the fat content provided 20% (low), 40% (medium) and 60% (high) of the calories. They tested lean people, obese people, and people who were obese because they have a defect in a gene called MC4R.

After taking a small taster of each meal, people were allowed to eat freely from the three kormas. They could not tell the difference between the foods and were unaware that the fat content varied. ̽��ֱ��researchers found that, although there was no overall difference in the amount of food eaten between the groups, individuals with defective MC4R ate almost double the amount of high fat korma than lean individuals ate (95% more) and 65% more than obese individuals.

In a second arm of the study, people were given Eton mess, a dessert that includes a mixture of strawberries, whipped cream and broken meringue. Again, there were three options from which participants could freely choose, with sugar content providing 8% (low), 26% (medium) and 54% (high) of calorific content, but with the fat content fixed. Participants could choose freely which ones to eat.

Lean and obese individuals said they liked the high sugar Eton mess more than the other two desserts. However, paradoxically, individuals with defective MC4R liked the high sugar dessert less than their lean and obese counterparts and in fact, ate significantly less of all three desserts compared to the other two groups.

One in 100 obese people have a defect in the MC4R gene which makes them more likely to put on weight. ̽��ֱ��researchers think that for these individuals, the fact that the MC4R pathway is not working may lead to them preferring high fat food without realising it and therefore contribute to their weight problem. There are many other genes that increase the risk of gaining weight and the impact of these genes on eating behaviour needs to be studied in the future.

Professor Sadaf Farooqi from the Wellcome Trust–Medical Research Council Institute of Metabolic Science at the ̽��ֱ�� of Cambridge, who led the research team, says: “Our work shows that even if you tightly control the appearance and taste of food, our brains can detect the nutrient content. Most of the time we eat foods that are both high in fat and high in sugar. By carefully testing these nutrients separately in this study, and by testing a relatively rare group of people with the defective MC4R gene, we were able to show that specific brain pathways can modulate food preference.”

Professor Farooqi and colleagues think that humans and animals may have evolved pathways in the brain that modulate the preference for high fat food in order to cope with times of famine.

“When there is not much food around, we need energy that can be stored and accessed when needed: fat delivers twice as many calories per gram as carbohydrates or protein and can be readily stored in our bodies,” she explains. “As such, having a pathway that tells you to eat more fat at the expense of sugar, which we can only store to a limited extent in the body, would be a very useful way of defending against starvation.”

̽��ֱ��research was supported by the Wellcome Trust, the National Institute for Health Research Cambridge Biomedical Research Centre, the Bernard Wolfe Health Neuroscience Fund and the European Research Council, as well the European Union’s Seventh Framework Programme

Reference
van der Klaauw, AA et al. Divergent effects of central melanocortin signalling on fat and sucrose preference in humans. Nature Comms; 4 Oct 2016; DOI: 10.1038/NCOMMS13055

People who carry variants in a particular gene have an increased preference for high fat food, but a decreased preference for sugary foods, according to a new study led by the ̽��ֱ�� of Cambridge.

Our work shows that even if you tightly control the appearance and taste of food, our brains can detect the nutrient content

Sadaf Farooqi

Patrick Talbert

Chicken Korma with Nan Bread

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes

Licence type:

Attribution-Noncommercial-ShareAlike

Healthy vs unhealthy food: the challenges of understanding food choices

amb206 — Fri, 11 Mar 2016 08:00:00 +0000

̽��ֱ��solution to the obesity epidemic is simple: eat less, move more. But take a deep breath before you type these four words into a search engine. ̽��ֱ��results exceed 9 million. Of the top four results, two websites argue against the statement and two for it. Below, arguments about eating and exercise rage fast and furious with dozens of assertions backed by equations, flowcharts, promises of slimming success, and lists of the latest superfoods.

“Despite all we know about food, we know remarkably little about the process of food choice,” says Dr Suzanna Forwood, until recently Research Associate at the Behaviour and Health Research Unit (Cambridge ̽��ֱ��) and now Lecturer in Psychology at Anglia Ruskin ̽��ֱ��. “In a supermarket we’re bombarded with the thousands of products on the shelves and but most of the time we happily make relatively quick decisions about what to buy. So what’s going on in our minds when we reach out for our favourite breakfast cereal?”

When it comes to eating, we’re all experts. We’re secure in our own opinions (and prejudices) and have no shortage of advice for everyone else. ̽��ֱ��truth is that, in common with many human activities, our relationship with food is complex and deeply embedded in culture. Forwood says: “Whenever I give a talk, even to an academic audience, people will listen to me talk about the big picture and then come up to me afterwards to tell me about their personal experiences – typically what they spotted in other people’s trolleys the day before.”

We might broadly agree that eating less (and better) and moving more, a message endorsed by the NHS, makes sense – but do we act accordingly? We don’t. Finding out exactly what people eat is hard, finding out why they make those choices is harder – and changing those eating patterns is harder still. “Most of the data we have – and we have lots of it – is observational rather than experimental,” says Forwood. “There have been relatively few experiments looking at food choice – and those that have been carried out tend to have a low number of participants.”

In the late 1980s government began to realise that it was facing an obesity epidemic on a scale that demanded intervention. Levels of obesity in the UK have tripled since 1980: almost 25% of the adult population is now obese with the UK topping the tables for Western Europe. These worrying figures led to nationwide initiatives to promote healthy living – and increased efforts to understand food choice behaviour.

Research has shown that obesity is linked to deprivation and low levels of education – as well as to a whole range of life-threatening conditions. Top of the list of ‘avoidable diseases’ associated with obesity is type 2 diabetes (treatment of type 2 diabetes costs the NHS an estimated £8.8 bn each year), followed by cancer, high blood pressure and heart disease. “In the past, weight status has long been regarded as a matter of personal choice,” says Forwood. “And this is reflected by the government’s desire for non-regulatory interventions.” ̽��ֱ��preference for a light touch approach is exemplified by the establishment of the so-called Nudge Unit (Behavioural Insight Team).

In 2009 the government launched its Change4Life campaign as a ‘movement’ to improve the nation’s health. Change4Life’s online advice for adults makes a series of suggestions for ‘swaps’ and ‘nudges’. Swap a large plate for a smaller one, swap fast eating for slow eating, and swap food high in fat or sugar for healthy fruit and vegetables. Look closely at labelling and make healthy choices based on a comparison of calories and nutritional information.

̽��ֱ��current focus is on reducing intake of sugar – not the sugar that occurs naturally in fruit, or even the sugar we sprinkle on our cereal, but the hidden sugar that sweetens so many processed foods and flavours so many popular drinks. In the case of sugar, what is proposed is a financial nudge in the form of a ‘sugar tax’. “Taxes have been shown to be effective but they have to be carefully designed,” says Forwood. “Sugar taxes, for example, need to avoid raising the price of fruit juices which are high in sugar.”

Do other strands of swaps and nudges work? Research suggests that people are remarkably resilient in their food choices. Taste emerges as the most important factor. Forwood’s work shows that healthy foods (such as fruit and vegetables) are not perceived as tasty, particularly by groups who are reluctant to choose healthy foods. She says: “That might seem tautological but there is strong observational data to suggest that perceiving food as tasty is important. It’s not good enough simply to tell people what is healthy if they don’t think those foods are also tasty.”

̽��ֱ��perception of healthy foods as less tasty than unhealthy foods prompts the question: could product labelling, promoting the tastiness of healthy foods, nudge consumers into making ‘better’ choices when they’re shopping. In research published last year, Forwood and colleagues looked at the ‘nudging power’ of labelling to increase the percentage of people who might say ‘no’ to a chocolate bar and ‘yes’ to an apple as part of a notional meal deal.

In the online study, around half of a representative sample of people expressed a preference for an apple when given the choice of apple or chocolate bar. Participants were divided into five groups and given the same choice (apple or chocolate bar) with the apple labelled in five different ways: ‘apple’, ‘healthy apple’, ‘succulent apple’, ‘healthy and succulent apple’, ‘succulent and healthy apple’. Labels combining both health and taste descriptors significantly increased the rate of apple selection – to 65.9% in the case of ‘healthy and succulent’ and 62.4% for ‘succulent and healthy’.

Another study, also published last year, looked at the potential for food swaps – often used as part of social media campaigns – as a means for reducing dietary levels of energy, fat, sugar or salt. Using the model of an online supermarket, built as a testing platform, participants were asked to complete a 12-item shopping task. In the course of the purchasing process, they were offered alternatives with lower energy densities (ED). For each item, lower ED alternatives were offered or imposed, either at the point of selection or at the checkout.

“Our study showed that within-category swaps did not reduce the ED of food purchases. Only a minority of swaps were accepted by the consumer and the notional benefits to swaps were slight. It was striking that more than 47% of the participants offered alternatives did not accept any of the swaps they were offered,” says Forwood. “Female participants and better-off participants were more likely to accept swaps. This was predictable in that these are the people who we know from other research typically make healthier choices anyway.”

It has been argued that omnipresence of food imagery in the modern built environment, and via all kinds of media, contributes to rising rates of obesity with adverts for less healthier foods identified as a driver for consumption of such foods. A study in Australia showed that people who watched commercial television channels (which carry advertising for fast foods) were, perhaps not surprisingly, more likely to purchase TV dinners.

“What we’re talking about here is, of course, observational data,” says Forwood, “It may, for example, be that people who consume TV dinners are more attracted to certain television programmes that are on commercial channels. Remember that huge sums of money are spent targeting TV adverts in order to make sure that the right population sees them. But this raises the question: could advertising represent an opportunity for policy makers looking to promote consumption of healthier choices?”

‘Priming’ is described as a psychological effect in which exposure to a stimulus – such as advertising – modifies behaviour. When Forwood and colleagues tested the effectiveness of priming by asking volunteers to look at an advertisement for healthy food (such as fruit) and then choose between healthy and unhealthy, they found that the priming had little difference. ̽��ֱ��observations were different, however, when the participants were hungry, in which case the preference for the energy dense foods rose. However, when the hungry volunteers were shown an advertisement for fruit in advance of their choice, the ‘hungry factor’ was offset by the priming.

̽��ֱ��initial experiment was carried out in Cambridge where the participants were predominantly female, well-educated and older – and likely to be in favour of healthy eating. When the experiment was carried out with a more nationally representative sample, the results showed that priming was ineffective in socially disadvantaged groups. “These people are hard to reach and represent a real challenge to policy-makers,” says Forwood. “Research tells us that 89% of people want to make dietary changes to improve their health. We need to identify the levers that can support them.”

We know a lot about food but little about the food choices that affect the nation’s health. Researchers have begun to devise experiments to find out why we choose a chocolate bar over an apple – and whether ‘swaps’ and ‘nudges’ are effective.

Perceiving food as tasty is important. It’s not good enough simply to tell people what is healthy if they don’t think those foods are also tasty.

Suzanna Forwood

Flickr Creative Commons

Nancy's Fruit Salad by John Hritz

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

Yes