Easiest diet to lose weight fast is Keto.
Essentially low carb (~5%), high fat (~60%), and protein at ~35%.
Now this may seem like... omg HEART ATTACK. But there aren't any studies that can actually prove that.
Basically sugar is the enemy. Carbs are the enemy.
If you're carbs are low enough (>~20g/day), you're body is going to be in a state of ketosis. Since there's no carbs available, it's gonna be using fat as a primary fuel source. Also carbohydrates are what cause a insulin response, if you don't spike your insulin, you're not gonna store glucose or accumulate to much stuff