Various studies have indicated that increased consumption of unhealthy food is one of the major factors contributing to obesity. So, it is logical that making changes in diet will help reduce weight. But before modifying the diet, various factors such as BMI, weight loss goals, comorbidities, and socioeconomic status need to be considered. Individualizing the diet will cater to the person’s needs, making it easier for them to achieve long-term weight loss.
Different dietary approaches lead to weight loss if people adhere to them since they are all calorie deficient. Some of these diets reduce carbohydrates and some reduce fat. It is still not clear if one is truly better than the other in long term. In most cases, weight loss of approximately 0.5 kg per week can be achieved with a 500 kcal deficit diet that is adequate in carbohydrates and proteins, low in fat, and high in fiber. Individuals will find this diet effective as it is easier to follow in the long run, but this may not be applicable for those with higher degrees of obesity (say BMI of > 35).
For people with a BMI of > 35, a much more intensive diet restriction under the regular supervision of a dietitian is required. This would mean a higher restriction of calories (mainly from carbohydrates) replacing it mostly with proteins and lesser so with fat. These diets must be supervised by a dietician.
Another restrictive diet is the ketogenic diet which consists of high fats (55-60%), moderate proteins (30-35%), and a very low content of carbohydrates (5-10%). The ketogenic diet is superior in producing rapid weight loss in otherwise healthy patients with obesity. The clinical impacts, safety, tolerability, efficacy, and duration of treatment with these diets and potential for weight regain after discontinuation is not well understood. A ketogenic diet may be followed for a minimum of 2 to 3 weeks up to 6 to 12 months. Close monitoring of renal functions while on a ketogenic diet is imperative, and the transition from a ketogenic diet to a standard diet should be gradual and well-controlled. Your dietician is the best person to help you understand the diet and suggest appropriate personalized modifications.