It’s not that simple. BMI (Body Mass Index) is calculated using your height and weight. Because it does not take into account the percentage of body fat and cannot say anything about body composition, it is quite an unreliable measure when used in isolation .
Also, even if you have a high body fat percentage, it doesn't necessarily mean you are unhealthy. The location where the fat is stored is also important. If you have a lot fat around your middle (known as visceral fat located near the organs), you are considered to be at a higher risk of certain diseases because this fat can affect your internal organs. Even research shows that visceral fat is a better measurement of health .
Weight is not a direct indication of health, but it is usually associated with a poor-quality diet, lack of exercise, and low esteem. The ketogenic diet can help you work on your body composition, whether it’s adding muscle or reducing fat.