> Meditation and mindfulness practices may have a variety of health benefits and may help people improve the quality of their lives. Recent studies have investigated if meditation or mindfulness helps people manage anxiety, stress, depression, pain, or symptoms related to withdrawal from nicotine, alcohol, or opioids.

> Other studies have looked at the effects of meditation or mindfulness on weight control or sleep quality.

> However, much of the research on these topics has been preliminary or not scientifically rigorous. Because the studies examined many different types of meditation and mindfulness practices, and the effects of those practices are hard to measure, results from the studies have been difficult to analyze and may have been interpreted too optimistically.

This is just a polite way of saying "there's no evidence of them actually doing anything*".

I mean, that's exactly what you'd tell someone who believed in the healing powers of homeopathy or chiropracty(sp?).