Who benefits from a LCD- low carb diet?

Research suggests that low carbohydrate diet can improve numerous health markers, such as triglycerides, HDL (good) cholesterol, C Reactive Protein, blood sugar, and blood pressure reducing risk factors associated with type 2 diabetes and metabolic syndrome. Other conditions that may improve include arthritis, brain fog, cognitive impairment, and digestive complaints, like GERD and IBS, if done right.

Is low carb healthy or not?