Machines Are Making Us Fat

Currently, there is a rising prevalence of obesity and sedentary behavior. It is speculated that the availability of machines that aid in domestic work, such as washing machines and dishwashers, could be a reason for this. Women who work outside the home also seem to use these time saving home aids much more, resulting in a decrease in exercise. Results have shown that people who do not rely on machines for domestic work and walk to the office spend more energy. The authors conclude that reversing obesity and sedentary behavior by increasing non-mechanized domestic tasks and simple tasks like climbing stairs and walking to the office could be an effective intervention.

At present, there is a steep rise of obesity and much of it is attributed to increased sedentary behavior, increased energy intake, and low energy spending. Earlier, only high-income countries reported higher rates of obesity, but now even low and middle earning countries are reporting a rise in obesity levels. It is believed that with the advent of automated appliances to perform day-to-day tasks like cleaning, washing clothes, and doing the dishes, there is less energy spending than before. With the reliance on transportation to reach the workplace and the use of elevators, there is far less energy spent per day by many people. Very little research has been done to study the effect of these aids on rates of energy expenditure and obesity. This study attempted to look into this association in depth.


  • The study was conducted in three different experimental set ups. 122 adults volunteered for the study.
  • For Experiment 1, 12 females and 11 males were asked to wash clothes with or without washing machines. The respective usage of energy was measured using suitable techniques.
  • For Experiment 2, 28 females and 21 males were asked to walk to their workplace. The energy spent was measured in these volunteers.
  • For Experiment 3, 13 females and 5 males were asked to record in a diary for one week the number of times they used the stairs and elevators at work or in their apartments. The total energy spent was measured for all volunteers.


  • The results showed that when domestic tasks like washing clothes are performed by hand, they require more energy expenditure.
  • Washing clothes by hand needed around 45 calories compared to an average of 27 calories per day by washing machines. Similarly, use of a dishwasher required average 54 calories compared to the mean 80 calories when dishes were washed by hand.
  • Walking to work leads to a mean of 83 calories energy expenditure compared to 25 calories when a motor vehicle is used. Similarly, climbing stairs leads to 1 calories per day use compared to the 3 calories per day if the elevator is taken.
  • The total difference of daily energy intake due to use of domestic machines was 111 calories.

The authors admit that they do not recommend that machines not be used for day- to-day work. Rather, they suggest that a balance should be maintained and simple measures like climbing stairs and walking to work will use more energy. Further studies that establish effective measures that can ensure larger energy expenditure are warranted.

It is known that with the rise of industrialization and an increasingly wealthy middle class, there is an increase in food intake and sedentary behavior, leading to low energy expenditure and higher obesity rates. The authors of this study speculated that the use of “labor saving” machines like washing machines, dishwashers, vacuum cleaners, and elevators resulted in lower energy expenditure. This study showed that in combination, these labor saving devices lead to a 111 calories per day lower energy expenditure. This ultimately leads to obesity in large populations. The authors “do not advocate elimination of such devices, however… would point out that to reverse the energetic impact of mechanization is readily within the grasp of us all.” This, they suggest, can be achieved by adopting simple energy spending measures like taking the stairs and walking to work.

For More Information:
Labor Saved, Calories Lost: The Energetic Impact of Domestic Labor Saving Devices
Publication Journal: Obesity Research, October 2003
By Lorraine Lanningham-Foster; Lana J. Nys; Mayo Clinic, Rochester, Minnesota

*FYI Living Lab Reports Are Summaries of the Original Research.


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