Check online for something called The No S Diet. It's not really a diet, but outlines an easy to understand plan for healthier eating. In a nutshell: No Seconds, No Sweets, No Snacks (except on days that start with S - i.e. weekends and special days). Basically the idea is that many people are overweight because they eat too much at meals, consume too much sugar, and eat between meals. This plan gives you a way to eat one serving of whatever foods you prepare for each meal, and allows you to indulge a little on weekends.
There's a book that goes in to greater detail, but honestly all the main points are right on the site:
nosdiet.com. I don't think the No S thing is a "quick fix," really, but one should see results over time if they follow the guidelines.
Fad diets and programs can help someone lose weight in the short term, but usually once the plan is abandoned, the person will revert back to the same habits that caused them to gain extra weight in the first place.