Being controlled by a stimulus means that whenever you see it you react to it. If food is that stimulus then when you see it you eat it.
This has become a problem for a lot of people. If you find yourself nibbling or binging on food then a solution is to control the stimulus.
There are three skills you need to practice until they form habits so you can better control your eating.
The first is to get food out of sight and reach except at meal times. The old saying 'out of sight out of mind' is what you're going for here. Get the candy and snacks out of the glove compartment, drawer at work, or community dish.
Secondly, eat only when you are sitting down and at a table. Your car and work desk are not conducive to you eating well.
The third is to focus on just eating when you eat. It's become common to eat in front of a screen, while driving, or in between other 'more important' activities. There are few faster ways to consume more than you intend than being distracted when you eat. Eliminate the multi tasking you think you're good at (you're not) and enjoy the food and experience of eating - undistracted.
In summation you want to outlaw the casual consumption of food. To do so you will control the stimuli of food itself and cut back on the competing stimuli of other things wrestling for your attention when you eat.