When the Supreme Court Justice Potter Stewart was asked how he defined hard-core pornography, he stated, “I know it when I see it”. The same might be true of obesity.
Obesity leads to early mortality. That is why the Metropolitan Life Insurance Company started compiling data on height, weight, and mortality in the 1940s to determine who was most likely to die, so they could adjust the cost of an individual’s life insurance policy and make money like any good bookie. These charts were based on height and weight. The ideal range indicated you were less likely to die. Above or below those ranges, your likelihood of dying was greater. Obviously, there were different tables for men and women. As time went on, the ideal body weight for longevity was further adjusted for frame size (usually based on the wrist circumference). Now the Metropolitan Life tables began to look like a computer printout sheet.
So, to make it simpler (and not to make it sound like the Metropolitan Death Tables), the concept of BMI was first introduced by Ancel Keys in 1972 because a single number could be applied equally to men and women, regardless of sex or body frame. The average BMI had remained relatively stable in the 1960s and 1970s (1) but started to increase in the late 1970s (2). By 1997, the obesity epidemic was spreading worldwide. The World Health Organization adopted the use of BMI to measure obesity, and soon afterward, the US government followed suit. The only trouble was that BMI levels had been rapidly increasing since 1980.
You are considered obese if your BMI is greater than 30. In 1960, about 13 percent of Americans would be considered obese, and that rate only slightly increased to 15 percent by 1980. Currently, 43 percent of Americans meet that criteria. That’s nearly a 300 percent increase in 45 years. Also, remember that the Metropolitan Life Insurance Company began publishing its tables because obesity was strongly associated with early mortality. The only reason Americans aren’t dying faster is that we have greater use of drugs to treat the problems created by obesity, even though the underlying issue (i.e., excess inflammatory fat) is out of control. However, what is decreasing is our healthspan, defined as the percentage of our lives spent in reasonable health. Currently, the US has the largest gap between healthspan and lifespan in the world (3).
Well, that is bad news. But what if reality is even worse than that? In early 2025, an international expert panel decided on a new definition of obesity based on far more objective measurements (4). Any one of these four definitions would classify one as obese:
1. BMI greater than 40
2. BMI greater than 30 plus one elevated body measurement (like waist circumference, waist-to-hip ratio, or waist-to-height ratio)
3. BMI less than 30 plus two elevated body measurements
4. Excess body fat by dual-energy x-ray absorption (DEXA) or similar body fat measurements like underwater weighing. Using these measurements, obesity is defined as body fat greater than 25 percent for males and greater than 30 percent for females.
Using these new definitions of obesity, researchers then applied them to more than 300,000 subjects (5). What they found was that the average percentage of Americans who would be considered to be obese had jumped from 43 percent using the old BMI standard to 69 percent with the new standards. That’s a 60 percent increase in obesity using more objective standards. Yikes!
This only means that healthspan will continue to decrease in America even if everyone takes GLP-1 drugs. The reason is that the clinical studies indicate that the decrease in obesity is significantly less than the weight loss (6). Individuals taking the GLP-1 drugs for more than a year were still obese even by the old standards of obesity using only BMI measurements. According to old Metropolitan Life Tables, they are more likely to die than individuals with a lower percentage of body fat. More troubling is that once they stop taking GLP-1 drugs, the lost weight returns, and most likely as new body fat, thus potentially making them more obese than when they started.
What is the solution? I believe it lies in Metabolic Engineering®. This is a life-long dietary program to activate AMPK, the master regulator of your metabolism. Metabolic Engineering® allows you to burn stored body fat faster while maintaining your lean body mass, reduce inflammation, repair damaged tissue more rapidly, and slow your rate of aging. This also means your healthspan will increase.
References
1. Pray R, Riskin S. The History and Faults of the Body Mass Index and Where to Look Next: A Literature Review. Cureus. 2023;15:e48230. doi: 10.7759/cureus.48230.
2. Temple NJ. The Origins of the Obesity Epidemic in the USA-Lessons for Today. Nutrients. 2022;14:4253. doi: 10.3390/nu14204253.
3. Garmany A, Terzic A. Global Healthspan-Lifespan Gaps Among 183 World Health Organization Member States. JAMA Netw Open. 2024; 7:e2450241. doi:10.1001/jamanetworkopen.2024.50241
4. Rubino F et al. Definition and diagnostic criteria of clinical obesity. Lancet Diabetes Endocrinol. 2025;13:221-262. doi: 10.1016/S2213-8587(24)00316-4.
5. Fourman LT, et al. Implications of a New Obesity Definition Among the All of US Cohort. JAMA Netw Open. 2025; 8:e2537619. doi: 10.1001/jamanetworkopen.2025.37619.
6. Wilding JPH et al. Once-Weekly Semaglutide in Adults with Overweight or Obesity. N Engl J Med. 2021; 384:989-1002. doi: 10.1056/NEJMoa2032183.
