TRYING to lose weight? Well, don't try an online diet plan, which consumer advocate Choice says will only set you up to fail.
The advocacy group enlisted the help of a "shadow shopper" to test three major online diets with the help of accredited dietitians and exercise physiologists.
Tests of the diets, including Sureslim, Ashy Bines and Weight Watchers, found both Sureslim and Ashy Bines went against "principles of eating a healthy, balanced diet".
Choice said the trial also found the shopper was given questionable advice under Sureslim, like "eating a mouth of protein first", which was not based on scientific evidence.
While The Weight Watchers program was found to be flexible and easier to track food intake, it cost more.
To avoid the pitfalls of questionable online programs, the consumer group advised people to check if diet programs were based on the Australian Dietary Guidelines and assess costs.
People seeking to lose weight were also told to talk to their general practitioner before trying any dieting program.