FACULTY SPOTLIGHT: AN INTERVIEW WITH PROFESSOR CHRISTOPHER GARDNER
By Tamara Sims
Based on Sightlines analyses, only 1 in 4 Americans report eating the recommended servings of vegetables and fruits every day. Older Americans and more educated Americans are more likely to; about 30% of them meet the guidelines. Does this surprise you?
Not surprised, but surely disappointed. One of the most visible public health campaigns of the past 30-40 years has been the “Five-A-Day” campaign encouraging people to eat more vegetables and fruits. Sadly, consumption in America hasn’t budged in that entire time. This result is easier to understand when you realize that the entire marketing budget for that campaign is less than just one type of candy bar from one of the 10 major food companies that control 90% of the food market. We need to work on our social marketing strategies and leverage better resources.
The Sightlines project used existing data on nationally representative samples to assess healthy diet of Americans. Throughout, we had a difficult time locating a reliable indicator of diet in these datasets. Can you comment on the state of diet measurement in scientific research? Is there a gold standard we should be using? If not, are we making progress towards achieving one?
You didn’t miss anything. The average major grocery store offers 30,000-50,000 items. ~50% of the food Americans eat each day was prepared by someone other than themselves (restaurants, prepared foods in markets, cafes and dining halls, etc). The only way to get at that is to ask people what they ate, and that process is tedious and inaccurate (i.e., they over and underestimate, forget, and sometimes lie). Rigorous collection of diet data means locking someone up and handing food to them while they are being videotaped, which isn’t generalizable. Getting more generalizable diet data from people in the real world isn’t very rigorous. It’s a trade off. Alternatively this can be looked at from the other direction: food that is produced in America. The USDA does this and makes the data available on their ERS website (Economic Research Service). But it doesn’t give you data about individual intake. I’m currently working with several colleagues on novel method to improve this – stay tuned.
There seem to be many approaches to studying diet: from examining the effects of nutrient intake; to consumption of particular foods (think eggs or kale); to some work zooming out to look at dietary lifestyles (e.g., the combination of foods ingested throughout a typical day), albeit less frequent. Why do these different approaches exist?
Part of the challenge here has to do with the scientific process, and what questions are more vs. less answerable.
Nutrition questions that involve isolated nutrients are easier questions to answer than the other two, because those questions can be asked with dietary supplements, and those types of trials can be run like drug studies: Pills vs. Placebos.
The problem with those studies is that they are usually done with certain foods in mind (e.g., a study of fiber supplements would relate to plant foods rich in fiber, and a study of dietary cholesterol would relate to eggs), but many Americans don’t understand or appreciate which foods are the highest or lowest in certain nutrients. Therefore, the practical implications of supplement studies are often lost on the American public, unless the study was truly trying to promote dietary supplements.
Studies done with whole foods are harder to do, because when you eat more of one food, you either now eat more calories (which is bad), or if you now eat the same number of calories you must have eaten LESS of something else. This makes it difficult to attribute the impact of this particular food on that food vs. something you didn’t eat when you chose that food.
Hardest of all is studying dietary patterns like: Mediterranean, Paleo, Vegan, Vegetarian, Atkins, Ornish.
First of all, most of those diets are hard to define clearly — which means two people could tell you they were both eating that same diet, but choosing to do it in different ways.
Plus, when scientists try to study people following those diets, they can ask subjects to change their current diet to follow the new (hard-to-define) diet, but it is extremely challenging to monitor their adherence to the new diet plan.
The best way to know that they are adhering to the diet is to buy it, make it, and feed it to participants in a locked living facility with cameras on them at all times.
I’m sure you can imagine that this can’t be done for long periods of time, and the average person wouldn’t sign up for this kind of study.
In your opinion, why aren’t people eating as healthily as they need to be?
My only short answer is that the biggest deterrent is America’s loss of basic food literacy. We are now food illiterate – we have no idea what goes into producing food, and bringing it to our table or mouths.
In the Sightlines project, we focused on diet as one behavior known to enhance longer lives. What is your advice to younger generations who are likely to live to 100 and beyond?
My advice is for them to all take my human nutrition class, and my food and society class. Between the two they would likely learn a lot that could help them. 🙂
Of course that would be ~6 months and hundreds of hours of their time, and it is not a serious suggestion. The advice I would give today is different than the advice I would have given a decade ago. My advice is for them to do their best to increase their Food Literacy.
I could tell them all about nutrients and science, but I think a better way to choose a better diet is to spend more time understanding and getting engaged with where their food comes from, and how it gets on their plates.
If they knew the whole picture, many of them would be shocked and disturbed and motivated to change their behaviors and choices.
Cook more for yourself, and if you don’t like to cook at least ask more questions about the food from those who cook for you.
Americans, perhaps more than almost any other culture, have lost their basic food literacy, and this makes it difficult for them to wade through the swamp of food and nutrition claims that they are barraged with, and that leads them to make convenient, inexpensive, and attractive looking choices that are poor nutritional choices.
Hug a chef. Become more of a chef (or at least more of a cook).