Nobody "dies from obesity" they die from diseases caused by obesity. Just like smokers don't die from smoking, they die from things like lung cancer or heart disease. But does that mean the smoking didn't cause those issues? Hell no. If they didn't smoke, they likely wouldn't have died from lung cancer or heart disease. Just like if someone isn't obese, they are less likely to die of a heart attack, heart disease or colon cancer. Obesity is the catalyst.