Researchers at the London School of Hygiene and Tropical Medicine have found that commuters who travel to work by walking, cycling or public transport, have a significantly lower body mass index (BMI) and percentage body fat, compared with those who use private transport (predominantly the car, but also taxi, moped and motorbike).
A total of 15 777 people were included in the study. Factors such as age, disability, diet quality, participation in sport, and physical activity in the workplace, were all allowed for in anticipation that they might affect any association between commuting mode and obesity. Men who commuted via public or active transport modes were found to have BMI scores respectively 1.10 and 0.97 lower than those using private transport. For women, the corresponding figures were 0.7 and 0.87.
A key finding was that the effects observed for public transport were very similar in size to those for walking or cycling, probably due to walking between transport hubs and making journey connections. The observed effect size for men of around 1 BMI point suggests that, for the average man in the sample (43 years old, 176 cm tall, weight 86 kg, and BMI 27.8), this would equate to a difference in weight of 3 kg (almost half a stone). For the average woman in the sample (43 years old, 163 cm tall, weight 72.8 kg, BMI 27.4), an effect size of around 0.7 BMI points would correspond to a difference in weight of approximately 2.5 kg (5.5 lb).
(Associations between active commuting, body fat, and body mass index: population based, cross sectional study in the United Kingdom. British Medical Journal, online 19 August 2014.)