The Devilish Effect of a ‘Health Halo’

Photo courtesy of Flickr user Candi Mandi

Photo courtesy of Flickr user Candi Mandi

Go ahead , they’re low fat!

Haven’t you heard that before?  Haven’t you thought that?

You’re not alone.  Lots of people tend to let down their guard when they think something is low fat. It’s a tempting lure on food labels and on restaurant menus.  A low-fat label can be a blinding spell that researchers have dubbed a “health halo,” and this devilish effect could be adding to your unwanted pounds.

The concept of a health halo has been around for several years now, and new studies continue to document the potential downfall.  I first wrote about the health halo a few years ago for Researchers at Cornell University found that people who chose low-fat snacks ended up eating even more calories compared to their counterparts who selected regular snacks.  The low-fat snackers consumed 90 more calories — presumably because they mistakenly thought low fat = low calories.

I interviewed co-author Brian Wansink at the time who described low-fat labels as “hidden persuaders” that can get you to overeat or to eat more than you intended.

Studies have repeatedly shown that putting a low-fat label on food causes people, especially those who are overweight, to underestimate its calories, to eat bigger helpings and to indulge in other foods.   Researchers believe low-fat labels give people the mental permission to eat more.  They may feel less guilty about their choice — which leads them to eat more.

John Tierney wrote about the effect of health halos in the New York Times. He participated in an interesting study that stopped people on the streets of New York to ask them how many calories they thought were in two restaurant meals. Half were shown a picture of an Oriental Chicken Salad with a soft drink, the other half were shown a picture of the same salad and drink plus two crackers that were prominently labeled as “trans fat free.”

Guess what happened?  People overestimated the calories in the first meal — they thought it contained 1,011 calories, yet it was 934 calories.  In the second meal, the crackers added 100 calories to the meal, bringing it to 1,034 calories, but their presence skewed people’s estimates in the opposite direction.  The average estimate for the meal was only 835 calories — 199 calories less than the actual calorie count, and 176 calories less than the average estimate by the other group for the same meal without crackers.  The researchers concluded:

The trans-fat-free label on the crackers seemed to imbue them with a health halo that magically subtracted calories from the rest of the meal.

A new University of Chicago study published in the Journal of Consumer Research found that calling a food “healthy” may make you hungrier.  Researchers conducted several experiments to explore the impact of health claims and the relationship to satiety.  They found that when people ate food described as “healthy” they were hungrier afterwards compared to people who ate the same food described as “tasty.”  In fact, the people who ate “a new health bar” felt hungrier than if they hadn’t eaten a bar at all.    However, when given the chance to decide between a “healthy” or a “tasty” bar, there was no difference in hunger levels between the two groups.  The authors concluded:

When people feel obligated to eat healthy, it’s making them hungry and they eat more.  When they eat the same food because they have free choice, they are not going to rebound by eating a lot.

Beyond healthy, low fat and trans fat free, many of today’s popular health claims including reduced calorie, cholesterol free, no high fructose corn syrup, organic and all natural can lead people to select foods, especially snack items, without paying much attention to whether these foods are truly nutritious choices.  The virtuous image created by the health claim seems to short circuit the normal process of evaluating foods.   An organic cheese puff is still a cheese puff.  A sweetened drink or dessert that claims no high fructose corn syrup still contains sugar and the same number of calories as before.  The glare from these health halos tend to make people over-estimate the nutritional value of these foods and under-estimate how much they’re really eating.  Wansink calls health halos “invisible cues” that can make us reach for more.

So what do I believe? I think this is even more evidence  to enjoy real foods — and be mindful when eating.   Savor a small square of luscious dark chocolate instead of a slab of sugar-free candy, enjoy a pat of real butter on your toast or vegetables instead of reduced-fat stick margarine, and toss  your salad with  olive oil and vinegar  instead of low-fat bottled dressing.  Do not let low fat dominate your decisions about snacks.  Look at the total picture — calories and overall nutritional value — not just the low-fat label.  Bottom line:  Eat what you love and love what you eat.  Keep enjoyment part of the picture and keep sight of portion size.

I agree with Pierre Chandon, who has conducted some of the health halo research and was quoted in John Tierney’s article:

Being French, I don’t have any problem with people enjoying lots of foods.  Europeans obsess less about nutrition but know what a reasonable portion size is and when they have had too much food, so they’re not as biased by food and diet fads and are healthier.  Too many Americans believe that to lose weight, what you eat matters more than how much you eat.  It’s the country where people are the best informed about food and enjoy it the least.

What do you think?


The Biasing Health Halos of Fast-Food Restaurant Health Claims
Can Low-Fat Labels Lead to Obesity
Calling a Food “Healthy” May Make You Hungrier

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