Commuting for health
A study of more than 7,000 people in the UK supports the idea that walking and biking to work reduces obesity, but adds another wrinkle. Oliver Mytton and his team find incorporating at least some walking or biking into the commute, even if the rest of the trip is spent driving, also protects against obesity.
The findings help make sense of why some studies find using transit protects against obesity while others find only a weak association. Mytton’s results distinguish between those who take transit and walk or bike as part of their trip, and those who do not. (Logically, those who don't walk have transit stops very close to both home and work). As one might expect, there was little difference between the bodyweight of people who take transit without being physically active and those who drive daily.
The effect size in all cases, however, is small, ranging between 1% and 1.7%. The daily commute is only one piece of what it takes to be active, and being active is only one piece of what it takes to prevent obesity. Interventions must focus not only on the commute, but on walking for many reasons throughout the day, and on supporting access to healthy food.