An article on whether there is an optimal diet for weight management and metabolic health can be found here.
The bottom line is that while different types of diets may stress optimizing different health outcomes (low fat diets helping with LDL; low carb diets helping more with triglycerides and HDL), the main point is to adhere to a healthy diet. Both low fat and low carb can work; people have different preferences, but if you are overweight, sticking to a diet that results in weight loss will improve many metrics of health and fitness.
