New research shows “you are what … or rather … where you eat”

The old saying “you are what you eat” rings true, but what may be more accurate is “you are where you eat,” according to a new study by USC researchers in collaboration with researchers at Northeastern University and Massachusetts Institute of Technology.

Why it matters: Poor diets are a leading cause of illness and death, and exposure to environments saturated with fast-food outlets are believed to make it harder for people to choose healthy eating options.

A new study, published recently in Nature Communications, suggests that if we want to address the unhealthy food in Americans’ diets, we must address the kind of food consumed away from home and the number of outlets selling healthy options people are exposed to throughout the day.

Key findings: From a review of anonymized smart phone data, the researchers examined more than 60 million visits to food outlets in 11 American cities over 6 months.

• The researchers found that the more fast-food outlets people encounter as they travel throughout their day, the more likely they are to visit one.
• Because people are influenced by food environments, increasing the number of restaurants that sell healthy food options in areas with an abundance of fast-food restaurants will increase the likelihood of a person choosing to visit a healthy restaurant when they are away from home.
• There is no evidence that any particular socioeconomic group visits fast food outlets more than another.

Super sizing: People visiting areas with 10% more fast-food outlets were 20% more likely to stop at one.

• For example, when comparing two areas with 10 restaurants each — one with five fast food and five healthy, the other with six fast food and four healthy — people in the second area are 20% more likely to choose fast food.

The big picture: Millions of Americans suffer from food and nutrition insecurity, struggling to access enough healthy foods.

• For decades, efforts to combat nutrition insecurity and low-quality diets have focused on identifying “food deserts” — neighborhoods with few healthy, affordable food options — and “food swamps,” where fast-food restaurants abound.
• Research has shown that improvements to neighborhood food deserts and food swamps often fail to improve residents’ dietary habits or curb rising obesity and diet-related diseases.
• Since 2010, initiatives like the U.S. Department of Agriculture’s Healthy Food Financing Initiative, which supports healthy food retail in underserved neighborhoods, have been ineffective in changing eating habits.

In her words: “We’ve been encouraging people to eat healthy for 100 years, and it often doesn’t work. Even when people want to eat healthy, there are too many things in their day-to-day lives and environments that make it hard,” said Kayla de la Haye, founding director of the Institute for Food System Equity at the Center for Economic and Social Research at USC Dornsife College of Letters, Arts and Sciences. “Now we’re gaining a more comprehensive understanding of how food environments affect diet beyond the home.”

The researchers, led by Northeastern’s Esteban Moro, recommend that policymakers and others who want to improve food environments use mobility data to improve results.

• This kind of data can enable them to identify places where fast food is more prevalent than healthier food and places where peoples’ food decisions are most susceptible to the food environment.
• “The data offers a kind of roadmap to see where people are most likely to respond to an intervention — places where we know that if a healthier option were available, people visiting these locations would be more likely to choose it over fast food,” said Abigail Horn research assistant professor of industrial and systems engineering at USC Viterbi School of Engineering. “Those are the locations where we should implement interventions.”

The bottom line: Increasing the number of restaurants that sell healthy food options in the areas people routinely travel from their home neighborhoods can have two to four times the impact on their choice of healthy food, compared to efforts to increase the number of healthy restaurants exclusively near residential areas.