The truth is that there is no single way to eat for good health. As a species, humans are quite similar on a genetic level, yet as individual specimens we can be amazingly diverse.

How can both diets work? When planned well, each diet includes lots of vegetables and minimizes highly processed foods. Those are the common denominators of a healthy diet. From there, you can fill in the blanks to suit your tastes and your unique physiological needs by adding your choice of high-quality fats (nuts, seeds, avocados, olive oil, fatty fish), carbohydrates (whole grains, fruit, starchy root vegetables), and plant- or animal-based protein (legumes, soy, fish, lean sustainably raised meat, poultry, eggs, dairy). It takes a varied diet to get the vitamins, minerals, fiber, and phytochemicals required for optimal health, but there are many combinations of foods that can get you to that goal.

While everyone needs carbohydrates, fat, and protein, there is no "magic" ratio that you should be striving for, as long as you avoid extremes. In fact, a number of recent studies have found that the quality of the food you eat—particularly emphasizing whole foods over processed food—is more important than whether it's low-fat, low-carb, or somewhere in between.

Source: Harvard