There are several reasons why the Forking Diet works, none of which may be obvious at first, because it’s not a drastic diet (and we all know they're all pain and zero gain!).
First of all, you will hardly eat any sugary or fatty foods in the evening, which is the time when your organs usually store excess as fat.
Secondly, your food intake is reduced: the decrease in intake just from eating forkfuls actually makes a big difference, and you soon get used to being full after a fork meal.
Finally, because there are no restrictions on what you eat during the rest of the day (within reason!), there’s no risk of bingeing and yoyo-dieting, which cause your weight to fluctuate and are no good for long-term weight loss.