Many of you fail to follow the simple advice “Eat less and you will lose weight”, perhaps due to lack of will power. Most of you start dieting with the notion that you will experience fast results.
Experts tell you that if you cut around 500 calories from your daily diet, or burn them off exercising, then you can expect to lose 1lb (0.5kg) in weight every week.
But US researchers from the National Institutes for Health say this is a gross overestimation because the calculation used is flawed. They say it takes much longer to lose the weight – around three years to be precise, according to their work published in The Lancet. A year of dieting results in only half of the amount of weight loss that experts currently predict.
Dr Kevin Hall and colleagues say this explains why many of you give up within months, because you expect unrealistic results that cannot be achieved.
Studies of outpatient weight loss programmes show most dieters peak at six months with the pounds starting to creep back on after this.
Alternatively, as the slimmer begins to see the weight falling off in the early months they are so pleased with their achievement that they begin to relax and the diet slips. Eventually, the weight will catch up with them and they may well find they are now heavier than they were when they first started the diet.
The slow timescale for weight change is responsible for the gradual weight regain over many years despite the fact that the original lifestyle was resumed within the first year.
Dr. Hall says, professionals need to change the advice that they give to dieters so they don’t fall into this trap. The error occurs because the “500 calorie-cut a day” sum fails to take account of how metabolism changes as you diet.
Using knowledge about how the human body responds to changes of diet and physical activity, Dr Hall’s team have created a computer programme that they say gives a more realistic and reliable prediction of weight loss.
“But saying ‘cut out your daily habit of a 250-calorie chocolate bar and you will lose about 25 pounds and, if you stick at it, the weight will stay off’ – that is.”
However, Dr Hall says the computer model also shows how people can achieve more rapid weight loss if that is what they desire.
For example, someone could follow a very strict diet for the first year to get rid of a large bulk of their excess weight and then switch to a less restrictive diet to continue and maintain the weight loss. Adding in extra exercise will also have an impact.
There is no quick fix to dieting and if you want it to work you need to stick at it – Your will power matters. Healthy diet is for life.