There are people who eat too little, and too much, and who harm themselves not because they do or don't like food but because they hate themselves.
They deserve a degree of sympathy, and help with the mental health issues and addictions which are plainly causing serious harm.
Then there are those whose early death is being hastened not so much by sickness but by a terminal stupidity of the kind which makes Joey Essex look like Stephen Hawking, people whose lack of brain power is replaced by a towering edifice of denseness so severe it would make Charles Darwin despair for the future of the human race and piss off to the Galapagos to live with the finches forever.
This is best demonstrated by the tale of Britain's fattest woman, Brenda Flanagan-Davies of Gateshead, who at the age of 43 has achieved an almost matching weight of 40 stone.
Brenda eats six meals a day, troughing down 6,000 calories which include cheesy chips, cola, pizza, more chips, Chinese takeaways, pickles, chips again and an average of nine chocolate bars in 12 hours.
Because of her size Brenda needs the help of the welfare system to the tune of £36,400 a year to pay for a team of carers who wash her and prepare sensible meals which she also manages to tuck away in between the junk food, a reinforced bed, and various allowances to keep a roof over her head as she has not even been outside the house for four years, much less been able to get a job.
Brenda's days are spent shopping online for food - she spends about £1,000 a month - staggering a short distance to the shower, and reaching into the fridge beside her bed for the next snack. She managed to get married but on her one trip out with her husband she busted the front suspension on his Mondeo.
Brenda seems to be well aware of the problem, because she said that the bigger she gets, the sadder she gets, and the more she eats.
She said: "I want to help myself but don't know where to start."
I'll tell you where to start, Brenda. MOVE THE FRIDGE TO THE END OF THE GARDEN.
You'll soon be trotting up and down quite happily, I'm sure. And perhaps with a bit more movement and a few pounds off your self-loathing might lift and you'll get better in other ways too.
Everyone has a few wobbly bits - it's normal. People often call themselves fat when they're not. The obesely thick, however, those whose weight and stupidity are affecting their lifespan, are going to cost the nation millions over the course of even a shortened lifetime and harm the health of those around them as well. It must be easy to balloon from 20 stone to 40, because by that point you can't move much and care even less. But it's not like this creeps up on you, not that you contract a virus and wake up one day and suddenly need to call the fire brigade to help you take a leak. How does anyone not notice when they go from 10 stone to 15? It takes effort to eat 6,000 calories a day. I couldn't fit even half of Brenda's diet in my stomach, she's had to train to achieve this. Why did no-one step in at an early stage and explain this simple equation to her?
input - output = size
Fixing all the reasons for an eating disorder is difficult work. Brenda was bullied as a youngster, and although it was 30 years ago and she is now a grown-up, has the brain and willpower of a child. If she can't figure it out for herself the carers we are all paying a lot of money for need to move the fridge, unplug the laptop and perhaps ban the bloody chips.
But they won't, because they're pea-brained enough to have left cola within easy reach of a fattie who's too moronic not to drink something else. And it will probably be less than a week before someone even more incurably dim than Brenda appears in a newspaper to claim they're actually Britain's fattest woman and waaah waaaah waaaah.
If only I had a gun, they'd all start running around pretty quick.
Thick, sick, and infuriating to know.