Food is the foundation of health, but dividing food to healthy vs. unhealthy doesn’t make much sense

When we head out we figure if the weather's rainy or dry, and then decide on the umbrella. 

Assigning things into binary categories is useful for fast decisions. When it comes to food, something we choose constantly, we'd like to do the same thing, especially since there’s such variety and abundance around us – a quick shortcut is tempting.

And while most of us can see that the people we know are neither saints nor devils, most days are neither incredible nor horrible, and that the movie we just watched is neither a masterpiece nor a flop, food is all too often judged in a binary way: healthy vs. unhealthy.

A new study, led by Paul Rozin of the University of Pennsylvania, looks at the primary division of foods that first comes to mind in three countries: US, France and India.

The study included about 300 people in each country, and started with an open question: “If you had to divide all the things we eat and drink into two categories, what would they be?” In another part of the study the questionnaire participants ranked the importance of 5 binary divisions of the food world: animal vs. plant origin, food vs. beverage, healthy vs. unhealthy, natural vs. processed, French/Indian/American (depending on  the  country of the participant) vs. other. 

Obsessed with health foods

The most common default way in which Americans categorized food was according to healthy vs. unhealthy. This was the way they categorized most often when they were asked this as an open question. It was also the most important way to categorize foods when they had to rank the different dichotomies. It was the second most important to Indian participants, and the third for the French. 

For the French participants the most important categorization was natural vs. processed.

There was surprisingly no big difference between men and women among all participants. The authors also note that the animal vs. plant was rarely selected (animal vs. plant is actually the only factual binary way in which food can be categorized).

The authors conclude: “Our findings suggest that the food–health link is very salient for many individuals, especially Americans. Insofar as this strong mental link does not translate into lower food intake and more healthy choices, it may be counter-productive.” 

Can you really divide foods to healthy and unhealthy?

By definition, any broad categorization will be simplistic. I am often asked whether a food is healthy or not, and I admit that sometimes I will give an answer as short as “yes” or “no”, especially if I sense that there’s no patience or interest in a broader lesson about nutrition and wellness.

Food's healthfulness, however, exists on a grey scale.

The truth is that for most foods quantity and frequency determine the effect on health. You can gain unhealthy weight on perfectly nutritious foods that are minimally processed, and that boast many beneficial micronutrients – too much nuts, which are the epitome of healthy food, can do that. On the other hand, small amounts of indulgences such as chocolate or ice cream aren’t a threat to health. It’s this black and white way of training us to see food as good vs. evil that enables some processed foods to create a halo of ‘healthy’ that diverts us from thinking of the benefits and drawbacks of food as a continuum.

So yes, there are a few things that are pure junk foods, and that can easily be categorized as unhealthy – soda comes to mind. But most foods can’t be divided this way. On the continuum of healthfulness, there are sustainable ways in which people can improve their diet. If your dinner plate that once had a large steak, potato fries and a half cup of leafy greens transforms into one in which the leafy vegetables occupy half of that plate, the meat portion halved its size and the potato fries are replaced by roasted sweet potatoes, your food is healthier. We can’t characterize either version of that dinner as healthy or unhealthy, but one is more nourishing than the other, and if you repeat these choices again and again your diet improves. 

Food is many things, it's communal, traditional, sensual, cultural, it's our connection to the natural world. But even if your main goal is to support optimal health thinking about food primarily as healthy vs. unhealthy may be, as the authors suggest, counter-productive.

Dr. Ayala