People who commute to work by walking or cycling and public transport tend to have lower body weight and fat composition compared to those using private transport, according to a new study.

The researchers point out that the health benefits were similar for both active commuting (walking and cycling) and public transport, and this could have considerable implications for transport and health policy.

Researchers from the London School of Hygiene & Tropical Medicine and University College London looked at the relationship between active commuting and body mass index (BMI*) and percentage body fat.

They analysed 7,534 BMI measurements and 7,424 percentage body fat measurements from both men and women.

A total of 76% of men and 72% of women commuted to work by private motor transport, 10% of men and 11% of women said they used public transport, while 14% of men walked or cycled to work compared to 17% of women. The overall BMI score for men was 28 and 27 for women.

Compared with using private transport, it was found that travelling by public and active transport means had a significant bearing on lower BMI and healthier body composition for both men and women.

Men who commuted via public or active modes had BMI scores around one point lower than those who used private transport - a difference in weight of almost half a stone.

Women who commuted via public or active transport had BMI scores around 0.7 points lower than their private transport using counterparts, equating to a difference in weight of 5.5 pounds.

Results for percentage body fat were similar.

The researchers say these differences were more significant than those seen in many diet and physical activity interventions to deal with overweight and obesity.

They say although their study looked qt large numbers of people, no firm conclusions could yet be drawn about the direct cause and effect of transport modes on body weight.

The researchers suggest that the use of public transport and walking and cycling to and from work should be considered as part of strategies to reduce obesity and related health conditions, but further research on the subject was needed.

The study is published on bmj.com 

*Generally, a BMI of 18.5 to 24.9 indicates optimal weight, a BMI lower than 18.5 suggests the person is underweight, a number above 25 may indicate the person is overweight, and a number above 30 indicates the person is obese.