VeryGnawty's answer is good.
However I would change them a little.
1)Incorrect mental focus/priorities. This is caused by lack of information or incorrect info.
As a consecuence of that, it will lead to:
2) Eating wrong food, consecuently leading to:
3) Overeating because wrong food will create constant hunger.
4) Lack of exercise will follow as overweight people find it difficult to maintain adequate level of exercise.
5) Number of different things can happen after this like inadequate breathing, poor sleeping, lack of energy, depression etc.
6) If one didn't have any illnesses earlier, they will soon come as a consequence of above. No need to make a list but heart and cardiovascular problems and diabetes are close to the top of list.
If you are an overweight person: Do something about it!
Anything is better than nothing!
You CAN do it! Good luck.
SF