I like metaphors as much as the next person. Providing, that is, it's an accurate metaphor. But "fat is cancer" is one that doesn't fall into that category. People who use it are trying to push emotional buttons and stir up controversy. I get it. Apparently, it works to motivate some people.
Obesity is a serious disease. There is no doubt about it. But it isn't a disease of the body, it's a disease of the mind. The added bulge is merely a symptom of underlying emotional trauma. It's been shown over and over again that there is no physical treatment for obesity that will work consistently until the underlying mental disorder(s) are resolved. It's not that diets don't work - it's that they don't work all by themselves. No pill is going to cure your obesity. Antidepressants and appetite suppressants might help you lose some weight, but if you can't get your mind into a healthy place, that weight is going to come back again and again. And again. Cancer, on the other hand, is a biological mutation of cells that causes the body to attack itself and destroy organs such as skin, breast, lungs, et cetera. There are many many underlying causes for cancer - most are environmental (ie the chemicals we use on our bodies or that we are subjected to through our air, food, and water). However, even if you live the cleanest life possible, you may end up with cancer. It's a terrible, horrible disease that often strikes without warning or known cause.
Most doctors will treat cancer aggressively, as they should! There are specialists abounding in the field and they will give you the treatment to eradicate your cancer as best they can. For the most part, you can trust them to find a way to prolong your life. If your doctor, however, diagnoses you with obesity - they will most likely expect you to treat yourself. They will suggest and nag, tell you it's very simple, and see you in 6 months or a year to go over it again. If you are making progress with your weight, they will reward you with an "attagirl" and go about their day. If you are struggling they will suggest quick-fix surgeries and diets, almost never counselling unless you are severely severely obese, say 500 lbs. They will tell you what you already know - you need to exercise more and eat less. Perhaps they'll make sure you are taking your anti-depressants. They want us to take it seriously, and yet there is rarely a real treatment plan or referral. If nagging worked, our spouses and parents would've been able to cure us. Medical professionals could do more.
Obesity = disease. The obese individual IS the only person who can cure it but it is nearly impossible to do so without a system of moral support and information. Do our doctors really want us to attain healthy weights? If so, they need to have some serious plans of action for us. They need to refer us to dietitian's and psychologists, trainers, and others before surgeons. They need to see us more often than yearly if they expect to see and maintain any type of progress.
Also, I believe that if you think fat is cancer, you're doing a great disservice to cancer patients who suffer through difficult treatments on a daily basis. My husband is a cancer survivor and is now obese right along with me. We all know that obesity increases the chance of cancer recurrence, heart disease, and a multitude of other diseases and disorders. We know that burning more calories than we take in is the answer. However, if people are unable to deal with the emotional upheaval that is causing them to over eat and under-move, knowledge isn't necessarily power. This doesn't mean that a person is weak or stupid or lazy. This means they need support, both moral and medical. And scare tactics? They rarely work to do anything other than encourage people to dig their heels into the ground and resist.
OK, I'm all kinda all over the board on this post. I could go on and on, but I grow weary and the doorbell just rang.