Using fear of other peoples illnesses and maladies for long term motivation is eerily similar to all the "thinspiration" sites myself, and I'm sure many other people in particular women, frequented throughout eating disorders. Health is closely linked to diet and exercise- we have a quantity of control over how our life course will be charted in terms of our physical bodies. We sometimes confuse this quantity of control with absolute control- something which no one has. Some of us on this forum have had cancer, and some of us will get it. Some of us will get into car crashes, contract serious viruses, harbour bacterial infections, break hips, and have heart attacks. As Forest Gump indirectly said, "shit happens". Eating well and living a healthy lifestyle do not make us immune to cracks in our complex biological and genetic systems.
Those retirees picking up their pill bottles, do you think they are an image that should be feared? You will get old too someday, there is absolutely nothing that will stop that. Maybe you can delay the process, but one day you will be there. And maybe you will live long enough to see the complications that aging brings, and will have to rely on modern medicine to live out your days to a hopefully natural death. After one of my heart surgeries due to a genetic condition, people used to literally gawk at me in the cardiac award because I was so young- they showed me an amazing amount of sympathy and compassion. The elderly there were very supportive of me and would always want me taken care of before themselves, when a lot of them were suffering from the same condition and issues as myself- we both were stuck in a bit of bad luck, but they weren't feeling sorry for themselves or considering that their lives were not worth living. Getting sick and having things go off script is part of being a physical person in the world we live. This realization is what snapped me out of an eating disorder- I thought I could control what I looked like and how my body worked at every aspect. But no matter how fine tune you get your system, no matter your willpower, motivation, or drive, you will get older. If nothing else goes wrong, you at least know that. You might gain weight, lose weight, build muscle, eat less, eat more, whatever, you can't stop the march ahead. Building up your reality on a steady-state of constant levels means that as those start to fluctuate, the reality might just crack.
If the only thing you want to be is "not bad", your life will not be great. Fear creates a baseline- it takes something of much greater substance to elevate you to a lifestyle