Losing weight is twice as hard as you may think… cutting calories slows down your body's metabolismCutting calories leads to a slowing of metabolismConventional guidelines fail to take into account changes in metabolism, says U.S. expert
IF you are on a diet, look away now. Losing weight is twice as hard as thought, scientists said last night.
After factoring in how metabolism slows down as we shed pounds, they announced that dieters’ expectations have been too high.
And official guidance that cutting 500 calories a day will result in a pound of weight being lost a week is plain wrong.
Even tougher: Reducing your calorie intake slows down your metabolism, making losing weight even harder
But there is some good news, the same
experts have created on online calculator that allows would-be slimmers
to adjust their expectations and gain a more realistic picture of what
they can expect to achieve.
The Body Weight Simulator website –
at bwsimulator.niddk.nih.gov – estimates how much less that person will
have to eat, or how much more exercise they’ll have to do reach their
Official advice in the UK and the U.S. has long been that cutting
out 500 calories a day will lead to weight loss of a pound a week.
But the calculation assumes that
weight loss is steady and does not take into account that a person’s
metabolism slows down as they lose weight, making subsequent pounds
harder to shed.
This means weight is twice as hard to shift, the American Association for the Advancement of Science’s annual conference heard.
The old system says that cutting 100
calories a day will lead to the loss of 10lb a year. The revised rule
predicts just 5lb will be shifted.
Rather than expecting too much,
dieters should be patient, said Boyd Swinburn, an obesity expert from
Deakin University in Melbourne, Australia.
Advising slimmers not to set their
sights on more than a half a pound of weight loss a week, he said: ‘This
is extremely good. This is a marathon not a sprint.’