Effects of Weight Reduction on Sleep and Alertness in Long-distance Truck and Bus Drivers


The work of long-distance truck and bus drivers involves long days, irregular hours and long uninterrupted periods of sitting still. These factors may lead to unhealthy lifestyle choices and thus increase the accumulation of excess weight.

Individual lifestyle counselling is rarely planned for professional drivers even though their work is straining and they are often predisposed to long-term diseases. The aim of the one-year individual counselling regarding nutrition, exercise and sleep was for the drivers to achieve a 10% weight loss.


The project recruited long-distance male drivers who were aged between 30 and 62 and whose waist circumference was at least 100 cm. The exclusion criteria included sleep apnoea (pauses in breathing during sleep) and diabetes requiring medication.

The participants were randomly assigned to the intervention group and control group to allow more reliable investigation on the effects of lifestyle counselling. The participants in the intervention group took part in monthly counselling for a year. The control group members continued with their old lifestyles and then after 12 months they took part in lifestyle counselling for three months. The study lasted a total of 24 months. The final tests were completed in June 2012.


The drivers in the intervention group had six meetings and seven telephone sessions with a lifestyle counsellor. The meetings were held as close to the drivers' home or workplace as possible. During the second year, the control group received counselling through two meetings and three telephone sessions.

The aim of nutrition counselling was to help the drivers adopt the nutrition pie chart, eat regular meals and reduce their energy intake.

The increase in exercise focused particularly on walking which can also be done in short sessions during a workday. The aim was to take 4000 extra steps five days a week with the help of a pedometer. 4000 steps is equivalent to half an hour of brisk walking.

The target for sufficient sleep was at least 6 hours/day. The drivers were given a sleep hygiene manual prepared by a psychologist from the Finnish Institute of Occupational Health.


The tests were conducted at the UKK Institute at the beginning of the study as well as one year and two years after the study had finished. The drivers' height, weight and waist circumference was measured, they took part in a 2 km walk test and their balance, jump height and hand strength was tested, all of which are part of the UKK health-related fitness tests.

In addition, the drivers wore an actigraph device on their wrist for two weeks to monitor their amount of physical activity at work and in their free time as well as their duration of sleep.

During this period, the drivers kept a sleep diary and assessed their daytime alertness on the questionnaire scale. Their alertness was also assessed using a reaction time test at the beginning and end of two workdays. The tests required an extra effort from the drivers during several days. As a result, the study produced a great amount of data that is currently being analysed.

Schedule and funding

The project was funded by the Academy of Finland work research program between 2008 and 2011 with the aim of investigating if weight loss improves the alertness of an overweight driver.




Finnish Institute of Occupational Health and Helsinki Sleep Clinic



Katriina Kukkonen-Harjula, Senior Researcher



For publications (international and Finnish) of this research see the Finnish description.
To find the list of publications (Julkaisuja), scroll the page down.

More about the issue

Researcher Katriina Kukkonen-Harjula is interviewed on Tampere University web site. The interview covers the UKK Institute's research about weight loss of lorry drivers.

Read the interview


Last Modified: 27.11.2014


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