These two are similar in that they both focus on cutting carbs to change the hormonal signals for appetite and fat metabolism.
The ketogenic diet focuses on focuses on the importance of fuelling your body with healthy fats and sets a specific percentage of macronutrients – high in healthy fats (60-75%), adequate protein (20-30%), and low carbohydrates (5-10%) – in order to move your body into ketosis and fats, in the form of ketones, as its main source of energy.
The Atkins diet allows as much protein and fat as you want and has two phases. The “introductory” phase is actually very similar to the ketogenic diet in terms of nutrient ratios. But after that initial phase, you can introduce more carbohydrates (but still in limited quantity) to your diet. The Atkins diet was also modified to encourage people to eat more green vegetables and salads to ensure there was enough micro-nutrition.
Although similar, the ketogenic diet is believe to deliver more rapid health benefits and increased weight loss by applying the additional controls of recommended calorie intake and macronutrient ratios.