Lose Weight Fast on the Public Transit Diet

CC BY 2.0. Even pigeons take transit in London/ Lloyd Alter

Running to catch that bus is good exercise.

We have noted for years that cars make you fat, but a new study shows that transit makes you skinny. Researchers from the University of Illinois at Urbana-Champaign and Georgia Tech did a longitudinal study of the relation between public transit usage and obesity and concluded that there is a significant inverse correlation:

Specifically, a one percentage point increase of frequent public transit riders in a county population is estimated to decrease the county population obesity rate by 0.473 percentage points. This result supports findings in previous research that the extra amount of physical activity involved in public transit usage can have a statistically significant impact on obesity. In addition, this study also provides empirical evidence for the effectiveness of encouraging public transit usage as a public health intervention for obesity.

Co-author of the study, Sheldon H. Jacobson, explains to Science Daily that it's all about the last mile:

Opting for mass transit over driving creates opportunities for exercise that may otherwise not exist. Instead of just stepping out of the house and into his car, riders need to walk from their home to a bus stop and from their stop to their destination.

There are other factors involved as well; when we discussed this issue almost a decade ago, Felix Salmon called it an urban diet, noting that people who don't have a car can't fill their fridges with a ton of food; it is harder to carry all that stuff on the bus or bike, so they give more thought to what they eat and probably have a healthier diet.

Toronto subway car

In Toronto, you get exercise just walking from one end of the train to the other/ Lloyd Alter/CC BY 2.0

The researchers suggest that encouraging public transit use "is indeed an effective public health intervention for obesity." We already know that Uber and Lyft are eating into public transit numbers, and Jacobson expressed some concern that Uber and and Lyft might affect obesity rates as well.

Jarret Walker of Human Transit has noted that “Uber is becoming as a generic reason to let transit fall apart." Perhaps this study will help reinforce the notion that public transit is not only an investment in the health of cities, but also in the health of its citizens.