De invloed van calorie- en beweeginformatie op hoeveel je eet: Noraly Duizer's presentatie tijdens Student Research Conference

 Afgelopen week had Noraly Duizer de eer om haar bachelor thesis te presenteren tijdens de Student Research Conference (SRC) te Amsterdam. Op de SRC presenteren geselecteerde studenten hun bacheloronderzoek. Hoewel Noraly niet in de prijzen viel ging haar presentatie erg goed.

 

Afgelopen voorjaar gaf Noraly aan 148 deelnemers een portie chips met daarbij op de verpakking gemanipuleerde informatie over het aantal calorieen in een portie en hoe lang je moet sporten om deze calorieen te verbranden. Heeft deze informatie invloed op hoeveel mensen eten en hun concrete sportplannen? Maakt het de chips juist lekkerder en het schuldgevoel na het eten groter? Lees het in de paper van Noraly hieronder!

 

 

Wanting to eat healthier, but little healthy foods sold at McDonalds

Most fast food restaurants do not share their sales data of healthy foods, but that did not stop Lyndall Wellard and colleagues to find out how many healthy items are actually sold at the biggest fast food chain in the world. They observed what people bought at 20 McDonalds restaurants in Australia. Of the 1449 meal purchases observed, only 1% could be considered healthy, 65% were unhealthy and 34% were take-away (so impossible to determine whether food is healthy or not).

Only 1% of all meals eaten in the restaurant! That is not much... Why would you sell healthy foods in a restaurant when hardly anyone is buying it? As a service to the 1% die-hard dieters who really do not want burgers and fries? Or to create a healthier image which may lead to higher overall sales?

According to a survey among Americans, 47% said they wanted restaurants to offer healthier items like salads. Even 23% said they tend to order those foods. Apparently many consumers like to have these items on the menu. Maybe as a license to indulge? Research of Wilcox and colleagues already showed that adding a salad or fruit to the menu makes you more likely to order fries. And to make it worse: consumers also tend to believe that adding a healthy item to a meal magically decreases the number of calories of the total meal.

In my previous blog post, I discussed the essay of Marion Nestle and David Stuckler on the influence of large food companies on public health. They are right, healthier foods are inherently less profitable. At least when eating out, most consumers seem to just want to indulge (without feeling too guilty).

Snacking: what to do with the fourth meal of the day?

Snacking now constitutes 25% of calories consumed in the US, according to a study that was presented at the Institute of Food Technology meeting last month. This is about 580 calories per day, about the same size as a meal, according to professor Richard Mattes of Purdue University.

Why? There are more situations in which we are confronted with tempting food. Our internal hunger and satiety signals are weak, particularly when looking at large assortments of delicious treats. Refusing would require quite some self-control. What does not help, is that self-control is like a muscle in your arm, according to the well-known psychologist Roy Baumeister and his 'self-control-as-a-muscle-theory'. When used too intensively, it gets tired and is more likely to fail. Baumeister came up with the term 'ego depletion' to indicate that self-control is a limited resource. So the more you try to not give in to temptations the more likely you are to go for the 'forbidden' food in the end. Coupled with increased snack portion sizes available, it is not surprising that people get overweight. I guess there are two basic solutions: don't snack or snack smarter.

1)      Just do not snack 
When I was at Cornell last year, Jan Chozen Bays gave a very inspirational workshop about mindful eating. Mindful eating is paying full attention to eating without negative judgments. It is about being aware of physical and emotional sensations when eating. What struck me most during this workshop is that she said that we could learn to accept an empty stomach. It does not need to be filled immediately. Like Buddha, listening to the ebb and flow of hunger and desire, she explained. We are not used to that anymore, conditioned that we should not accept that nagging hungry feeling in our stomach. This reminded me of an old Dutch commercial with the slogan: 'Four o'clock: cup-a-soup, more people should do that'. Mindful eaters, however, do not look at the clock to decide what and when to eat, but listen closely to what their body is saying. Unfortunately, I still not that far in mastering the art of mindful eating...

Accept the 'four o'clock' feeling without snacking? (Still Cup a Soup commercial 1990s)

2)      Smart snacking: cut up your food 

You could switch to healthier foods, such as fruits. Another solution and probably more realistic for many of us is to cut up your food into smaller portions (maybe an interesting nudge?). David Marchiori and colleagues (see Journal of the American Dietetic Association) gave a group of study participants unlimited consumption from a bowl of candies. About half of the participants received candies that were cut in two pieces and the other half got the normal sized candies. Participants with the tiny candies ate about half compared to the other group. Although this was only a 60 calories difference, it showed that consumers typically view their consumption in numbers ('oh, I already had 5 candies) rather than quantities ('e.g. a handful). 

A related idea is to package your snacks in small-sized portions. A recent study of the Food and Brand lab gave one group of participants one large 400-calorie package of crackers and another group four smaller 100-calorie packs of the same crackers to eat during a television show. Results show that only overweight participants consumed more than double the number of calories when eating from the bigger package (384 calories versus 176 calories). Interestingly, all participants underestimated the number of crackers eaten. So, it is not the tracking of calories that is easier with a smaller package. Apparently, overweight people are more likely to rely on external cues (such as the need to open a new package) to stop eating, according to Wansink and colleagues.

The Negative Calorie Illusion - Do your calories also magically disappear from your plate?

A noteworthy study of Alexander Chernev in the Journal of Consumer Psychology (April 2011 issue) showed that people have misguided beliefs about the relationship between a meal healthiness and its impact on weight gain. Simply said; they believe that adding a healthy item (such as an apple or salad) to a meal magically decreases the number of calories in a meal.

The reason is that people tend to categorize foods as healty and unhealthy ones. Particularly dieters are more likely to believe in 'negative calories'.

This is not the first study on the so-called health halos. Health halos are associations that people have with certain foods or restaurants. Brian Wansink and Pierre Chandon found that there's a health halo around foods at restaurants like Subway that leads people to overeat on side dishes and grossly underestimate the number of calories they consume. Even organic foods have a health halo, as people believe they have fewer calories (according to a recent study of Schuldt and Schwarz).

Not so good news. At least, not for people who want to manage their weight and eat healthy. Good news for restaurants. Just simply add a salad to your meal or menu and everything looks more wholesome. Not surprising that most (fast food) restaurants already discovered this without doing any consumer research.

According to Chernev at his interesting blog: 'The focus of current public policy campaigns needs to shift away from the stereotypes associated with “good” and “bad” foods and toward the quantity of food consumed.'  I agree completely. And stop dieting: it poisons your mind with this kind of misbeliefs!