Researchers have claimed that weight loss food supplements do not actually help people stay in shape.
According to experts from the Peninsula Medical School at the Universities of Exeter and Plymouth, there is no evidence that the supplements - including those based on cabbage, fibre and plant extracts - help people shed weight.
In another study, German researchers also came to the conclusion that supplements designed to aid weight loss are not helpful in reality.
The UK team analysed existing studies, including those on guar gum, bitter orange, calcium, glucomannan, chitosan, chromium picolinate and green tea. Their findings were presented at the International Conference on Obesity in Stockholm.
The experts said: "The findings from systematic reviews fail to provide sufficient evidence that any food supplement can be recommended for reducing body weight.
"A wide range of herbal and non-herbal food supplements is currently being promoted for weight loss. While mainstream drugs for body weight reduction must demonstrate efficacy before receiving a licence, food supplements do not need to meet this requirement.
"Few food supplements have therefore been submitted to clinical trials, and many healthcare professionals feel uncertain about their therapeutic value."
"The findings of this research are to me fairly obvious, because when patients are turning to supplements to help control their weight, they are not actually dealing with the issues that have caused their weight gain in the first instance, most commonly being due to lifestyle and eating habits" - Paula Henderson, Hampshire