One can argue that his statement came true. Although Smoking Tobacco is still the single worst thing you can do to your body, The 2017 Surgeon general's report stated that obesity is responsible for 300,000 deaths every year in the United States. Obesity affects numerous areas of one's physical health.
** Lean Body mass is Muscle but in actuality, we are talking about lean body mass and default mass. Default mass is weight other than Muscles and Fat stores. Default Mass includes , bones, organs, blood, and other fluids. In addition, undigested food, and waste that has not been removed also add to the overall weight.
The closest to your actual weight you can get is early in the morning, no clothes, after fasting for at least 12 hours AND you went to the bathroom for "both". The CDC (below) recommends a health care professional uses estimated BMI along with waist circumference to determine if someone needs to move to a healthy weight.