The World Health Organization (WHO) describes overweight and obesity as one of today’s most important public health problems, which is escalating as a global epidemic. Obesity is a complex disorder involving an excessive amount of body fat. Obesity is not just a cosmetic concern. It increases your risk of diseases and health problems, such as heart disease, diabetes and high blood pressure. Therefore a need was felt to carry out this study. The present study was done to reduce the weight of Obese subjects based on Blood group diets concept. The blood group diets are one of the diets that are very less explored. It was originated from two American Naturopaths, Dr James D’Adamo and his son Dr.Peter D’Adamo who believed that blood group type is the key to how one burns the calories, the type of foods an obese person should eat and the subject will benefit from certain types of exercises. They recommended that eating to suit your blood group will help to lose weight, help to fight disease and boosts the immune system. Keeping the above points in view, the present study was carried out on fifty obese subjects who were selected by purposive random sampling from the region of Gurgaon (NCR). All the selected subjects were Obese and had followed many weight loss techniques in their past. Based on the theory given by Dr Peter D’Adamo protein rich diet in combination with carbohydrates and fats was provided to the obese subjects. The mean protein intake of the selected subjects was increased from 50.96±3.0 to 150.3±16.8 per day. The reduction in mean weight and BMI was i.e. from 101.1±85.8 to 64.2 + 6.72 and 35.5±6.0 to 26.1±5.5 respectively. The results achieved showed a positive link between high protein diet and weight loss in Obese subjects having blood group O.