Weight loss plans

I have found that eating at a calorie deficit leads to fat loss, and it doesn't matter what approach.

It is indeed very important to develop good goals, both short-term and long term. Then, as you say, develop strategies to make them work. Finding a way of eating that keeps you from feeling hungry while maintaining a deficit can be a very personal thing since we're all different.

The plan that works best for me for fat loss is to track what I eat and how much I move and try to maintain a reasonable deficit. Then, once the excess fat is lost, to continue tracking fuel and output to keep a balance of calories to energy expended so that I maintain my weight.

Slow and steady is another part of the plan. Twenty-one or 30 days ain't going to cut it. It takes months with a reasonable deficit to lose fat at a safe rate, and that builds the habits to maintain.

What the people above said. Also, some weightloss plans have one big disadvantage: people often don't know what kind of food keeps them full and happy before starting to lose weight. There's a whole period of discovery associated with this. Imagine doing a keto programme because the advertizing for something sounded good, and then you find out high fat doesn't keep you full at all or you don't enjoy eating this way. What do you learn from that? High fat is not for you, or losing weight is not for you? And if by any luck you manage to reach your goal weight despite it being hard, what happens then? Most likely you go back to old habits because the plan was so hard and you don't want to do it anymore. Lost the chance to learn about healthier habits and on how to maintain the weight going forward. The same is of course also true for every other way of eating.