A waist trimmer belt initially provides the visual illusion of weight loss through fat compression, and it causes sweating, which does translate to minor weight loss through water loss. However, this weight loss is not permanent; these belts do not work, according to Dietspotlight.com.
A waist belt compresses fat rather than eliminating it. While this creates an appealing look, it is not weight loss.
These belts do increase sweating in the waist region, so the scale registers the extra water lost. Unfortunately this weight returns as soon as one properly hydrates, and the extra water loss is not necessarily healthy.
Actual weight loss with the belt is negligible. The belts' true benefit besides the obvious slimming illusion is that they are able to provide some measure of back support and encourage good posture when worn properly. In addition, the constant pressure sometimes acts as a reminder to a person who wishes to lose weight, prompting him to choose lower calorie snacks or adhere to his exercise routine.