Most diets that claim to be the “ultimate” one for weight loss tend to facilitate caloric deficit. For instance, intermittent fasting gets you to consume fewer calories by limiting the amount of time in a day that you can eat.
Zero or low-carb diets restrict your intake of high-caloric foods like bread, pasta and sugar-laden foods, while high-fat diets increase your satiety levels with rich foods so that you take in lower calories overall.
The caveat? None of these will work if you somehow still consume more calories than you burn.
For any of these diets to work, you need to be in caloric deficit or surplus (depending on your goal) long enough for the results to materialise.
Commitment matters.