Office workers who opt to stand are likely to burn just nine calories an hour more than their seated colleagues, a study reveals.
Researchers from the University of Bath say their work questions the effectiveness of standing as a strategy to lose weight.
The study, published in the journal Medicine & Science in Sports & Exercise, found standing burnt about nine calories per hour more than sitting - the equivalent of one stalk of celery.
Workers aiming to burn off their morning latte would have to stand for an average of 20 hours.
Dr Javier Gonzalez, from the University of Bath, said: "The very small increase in energy cost of standing compared to sitting that we observed suggests that replacing time spent sitting with time spent standing is unlikely to influence our waistlines in any meaningful way.
"To put this difference in context, it would require an additional 20 hours of standing time, on average, to burn off a medium latte.
"Many people are becoming aware of the negative health effects of prolonged sitting, and so may opt for standing desks.
"These people should be aware that whilst there are still some health benefits to standing more, they should not expect to see drastic changes in their body weight.
"In order to lose body weight, people should focus on increasing physical activity and focus on their diet, too."
In the study, researchers at Bath and Westmont College in the US tested the resting metabolic rates of 46 healthy men and women.
Participants were then asked to either lie down, sit or stand before measurements were taken of their expired gases to assess calories burned through the activity.
Professor Gregg Afman, of Westmont College, said: "We found that energy cost increase of 0.65 kJ per minute from sitting to standing naturally, which equates to a 12 per cent difference.
"However, current interventions to reduce prolonged sitting like standing desks or wearable technologies only increase standing by a maximum of two hours per day.
"This limited time frame would cause a person to expend less than 20 kcals more each day."