Insulin is the Master Hormone
When you eat sugar or other carbohydrates, you turn insulin "on." If you're lean, it means that your appestat is functioning perfectly. If you are overweight, it's because your appestat is not working properly and isn't able to signal you when to stop eating.
When insulin is on glucose in the blood is too high, that's a dangerous situation, so until that problem is dealt with insulin will remain "on," and the signal from the hormone leptin telling you to stop eating is over-ridden.
Eating sweet things encourages more eating. Thus we tend to over-eat.
Eating to a Routine
We often eat for social reasons and not because we are hungry.
The tradition of eating three times a day doesn't have to be what we do, in many cultures people only eat twice a day.
In many city cultures, people eat six or seven times a day, usually with coffee, or alcohol, and always with carbohydrate food, cereals, toast, bagels, muffins, pizza, chips or cake. Insulin is turned ON, and kept running HOT all day. Eventually, that makes us sick.
These cultural behaviours are stronger than hormone auto-regulation. That's why in a family or a social group you can all get fat (or thin) together. Social behaviours and modeling are important to us.
Adding to Your Adipose Tissue
When insulin is on, if there is a continuing emergency, excess glucose is turned into fatty acids and stored in the adipose tissues (Fat tissues). When this storage begins, the adipose tissues respond by producing leptin, a hormone that in the appestat is supposed to turn off the desire to eat.
But leptin is overruled, by insulin, because there is still an emergency going on. There is glucose that must be stored. So the appestat doesn't work. You keep on eating.
If you are becoming insulin resistant (or carbohydrate intolerant), the ability of the body to pass glucose into the cells to become energy declines, and the amount of glucose available to make fat rises.
How to avoid Problems?
If you eat a very varied diet, including carbohydrates and sugars, eat less often, give insulin a chance to clear itself from the blood-stream.
Eat slowly, and eat low-glycemic index carbohydrates, keeping the insulin spike lower, and giving the leptin signal to stop eating a chance to function.
However, because you are reading this, quite likely the opportunity to do either of those successfully is long gone.
First of all, get ALL the obvious carbohydrate out of your diet. Sugar, cereals, bread, pasta, rice, potatoes, anything made with flour needs to go.
Look at what we know about fattening livestock. Knowledge that's 200 years old. It applies to us too.
Join a support group, get to know other people who have done this, and are doing it.
Get a little coaching and get as far down the path to nutritional ketosis as you can.
Now take the Banting Course from "The Real Meal Revolution." Waiting this long, doing preparation for the course will help you get the full benefit from the course.