Weight Watchers may not be thrilled that Jessica Simpson is pregnant AGAIN … But the singer might be happy with researchers’ news, if her BMI stays under 35.
Researchers studying the relationship of obesity and death looked for scientific articles that specifically reported Body Mass Index (BMI) and mortality for adults. After initially finding 7034 articles, just over 147 articles were accepted for the research. Then after eliminating overlap data, 97 studies were retained for analysis. The 97 articles provided a sample size of more than 2.88 million adults and more than 270 000 deaths.
Relative to normal weight, obesity categories of all grades combined, and grades 2 and 3 obesity were associated with significantly higher all-cause mortality. Grade 1 obesity overall was not associated with higher mortality (actually “insignificantly” lower), and being overweight was associated with significantly lower all-cause mortality.
In this study, researchers used the National Heart, Lung, and Blood Institute’s terminology for weight categories: underweight (BMI of <18.5), normal weight (BMI of 18.5-<25), overweight (BMI of 25-<30), and obesity (BMI of ≥30). Grade 1 obesity was defined as a BMI of 30 to less than 35; grade 2 obesity, a BMI of 35 to less than 40; and grade 3 obesity, a BMI of 40 or greater.
Summary …
Underweight (BMI of <18.5)
Normal weight (BMI of 18.5-<25)
Overweight (BMI of 25-<30) - a 6% lower risk [0.95 (94% CI, 0.88-1.01)]
Grade 1 obesity (BMI of 30-<35) - a 5% lower risk [0.95 (95% CI, 0.88-1.01)]
Grade 2 obesity (BMI of 35-<40) - a 29% higher risk [1.29 (95% CI, 1.18-1.41)]
Grade 3 obesity (BMI of 40 or greater) - a 29% higher risk [1.29 (95% CI, 1.18-1.41)]
All obesity grades combined - an 18% higher risk [1.18 (95% CI, 1.12-1.25)]
What doctors have known all along?
The researchers added that their findings are consistent with observations of lower mortality among overweight and moderately obese patients. “Possible explanations have included earlier presentation of heavier patients, greater likelihood of receiving optimal medical treatment, cardioprotective metabolic effects of increased body fat, and benefits of higher metabolic reserves.”
Researchers reported BMI in the English format … Body Weight in LBS; Height in inches.
The formula for BMI is …
Body Weight in LBS/(Height in inches)[SQUARED] X 703
A person 6’1″ = 73 inches. That person with a body weight of 200 LBS has a BMI of 26.38
(200/(73)^2)*703 = 26.38 (Click for this equation in Google calculator)
In the formula, you can use the Google search box to calculate your own BMI. Replace your body weight in LBS, and your height in inches.
SOURCE:
Katherine M. Flegal, PhD; Brian K. Kit, MD; Heather Orpana, PhD; Barry I. Graubard, PhD. Association of All-Cause Mortality With Overweight and Obesity Using Standard Body Mass Index Categories
A Systematic Review and Meta-analysis. JAMA. 2013;309(1):71-82. doi:10.1001/jama.2012.113905.