In the publication of Lenz et al., the central clinical conclusion is that the overall mortality is not increased “with overweight”. However, the authors fail to present an adequate discussion of a problem of all analyzed studies, namely the short periods of observation. For example, many of the studies listed in Table 2 covered observation for periods clearly less than 10 years. Even the meta-analysis of about 900 000 subjects (reference 17), which the authors specially emphasized, had a mean observation period of only 8 years, with a mean subject age of 46 years.
The influence of overweight – starting in early adulthood – can certainly not be reliably evaluated on the basis of such data. For example, it would without doubt be unjustified at the moment to transfer the central conclusion of the study – that overweight does not increase overall mortality – to an overweight subject who is now aged 20.
Footnotes
Conflict of interest statement
The author declares that no conflict of interest exists according to the guidelines of the International Committee of Medical Journal Editors.
References
- 1.Lenz M, Richter T, Mühlhauser I. The morbidity and mortality associated with overweight and obesity in adulthood. Dtsch Arztebl Int. 2009;106(40):641–648. doi: 10.3238/arztebl.2009.0641. [DOI] [PMC free article] [PubMed] [Google Scholar]