How to lose weight?
The general answer is eat less and exercise more. This really is a psychology question, not a knowledge question.

To lose weight, one needs to create a build a mental model that they can follow. For example, one pound of fat has 3500 calories, one needs to reduce the diet by that much to lose a pound of weight.

Another important factor is to get strong support from family and friends. The encourage from close people makes the process easier and more natural.

Controlling weight is one of the psychological challenge that many people face at some point. Create a plan to minimize the psychological challenge and follow the plan mentally.