There are many, many… many, different diets out there. Some will try to adjust your macro intake in different ways. What they all boil down to though is a caloric deficit.
Want to bulk up for strength training, consume more. Want to slim down, consume less. It’s that simple. (maybe not “easy”, but simple)
Where adjusting some of these macros can help is by getting you to adjust the “types” of calories you consume. Carbs and sugar don’t make us fat. Over consumption of them can. Protein, fats, and fibers don’t make us skinny. They just tend to make us feel fuller longer, so we tend to eat less. As a matter of fact, over consumption of those can still make us gain fat – just like carbs and sugars. It’s all about #balance and making sure you eat a well balanced diet, and not going over the caloric needs of your body.
What are my caloric needs Eric? Well, take your IDEAL body weight and multiply times 13. This will give you a rough place to start for your (maintenance) level. If you want to lose fat, you will need to consume 300 – 500 fewer calories than maintenance per day.