Body mass index and mortality: a meta-analysis based on person-level data from twenty-six observational studies.
ABSTRACT For this report, we examined the relationships between the conditions of being overweight and obese and mortality from all causes, heart disease, cardiovascular disease, and cancer.
We defined the categories of body weight according to level of body mass index, BMI=wt(kg)/ht(m)2, using classifications suggested by the National Institutes of Health and the World Health Organization. These classifications are as follows: "normal weight" is defined as BMI > or = 18.5, but less than 25; "overweight" equals BMI > or = 25, but less than 30; and "obese" individuals have BMIs > or = 30. Our investigation is based on person-level data from 26 observational studies that include both genders, several racial and ethnic groups, and samples from the US and other countries. The database consists of 74 analytic cohorts, arranged according to natural strata including gender, race, and area of residence. It includes 388,622 individuals, with 60,374 deaths during follow-up. We use proportional hazards models to examine the relationships between the BMI categories and mortality, controlling for age and smoking status. We use random-effects models to assess summary relative risks associated with the overweight and obesity conditions across cohorts.
The relative risks among the heaviest individuals for overall death, death caused by coronary heart disease (CHD), and death caused by cardiovascular disease (CVD) are 1.22, 1.57, and 1.48, respectively, when compared with the those within the lowest BMI category. The summary relative risk among the heaviest participants for death from cancer is 1.07.
We document once again, excess mortality associated with obesity. Our results do, however, question whether the current classification of individuals as "overweight" is optimal in the sense, since there is little evidence of increased risk of mortality in this group.
SourceAvailable from: Lluis Serra-Majem
Journal of Epidemiology & Community Health 08/2011; 65(Suppl 1):A329-A329. DOI:10.1136/jech.2011.142976l.17 · 3.29 Impact Factor
[Show abstract] [Hide abstract]
ABSTRACT: Obesity is a global health problem affecting all age groups, leading to many complications such as type 2 diabetes, systemic hypertension, cardiovascular disease, dyslipidemia, atherosclerosis, and stroke. Physiologically, obesity arises from metabolic changes in the tissues and organs of the human body; these changes result in an imbalance between energy intake and energy expenditure, which in turn results in increased fat accumulation in adipose tissue. Such fat accumulation predisposes individuals to development of several health problems. Two different obesity treatment drugs are currently on the market; Orlistat, which reduces intestinal fat absorption via inhibiting pancreatic lipase, and Sibutramine, an anorectic or appetite suppressant. Both drugs have hazardous side effects, including increased blood pressure, dry mouth, constipation, headache, and insomnia. For this reason, a wide variety of natural materials have been explored for their obesity treatment potential. Therefore, the present review focuses on the safety and efficacy of some herbal medicines in the management of obesity through covering their beneficial effects and mechanism of action.Applied biochemistry and biotechnology 04/2015; DOI:10.1007/s12010-015-1602-6 · 1.69 Impact Factor