A reduction diet aims to reduce body weight. There are numerous reduction diets, which differ in their methods partly considerably from each other. The nutritional assessment of these must, however, be very differentiated in detail, since the justifications range from scientifically sound to justifiable to nonsensical or even dangerous. The main goal of any serious weight reduction diet must be a long-term change in dietary behavior. To minimize the risk of weight cycling, weight loss should not exceed 0.5 kg per week on average. Other basic rules of recommended reduction diets for permanent reduction of increased body weight are:
- Formulation of the desired weight as a goal
- Learning the enjoyable and anxiety-free approach to food.
- Calorie intake according to basic needs (at least 1,200 kcal/d).
- Energy-reduced, low-fat, carbohydrate and fiber-rich diet.
- Protein intake in sufficient quantity (0.8 g/kg bw/d) and quality.
- Fat content of the diet of about 30% energy and PS ratio: > 1 (= limit saturated fatty acids in favor of monounsaturated and polyunsaturated fatty acids).
- Carbohydrate content of the diet of more than 50% energy.
- Supply of supplements (dietary supplements) to meet the vitamin and mineral needs.
- Sufficient fluid intake (about 45 ml/kg bw / d).
- No or only a little alcohol
- Keeping food logs to record eating habits.
- Acquisition of nutrition knowledge
- Regular physical activity.
The reduction diets can be divided into fasting diets or extremely low-calorie diets, energy-reduced mixed diets,diets with extreme nutrient ratios, low glycemic index diets, flash diets, as well as psycho diets. In addition, there are various body weight loss programs that include elements other than diet, such as exercise and behavioral therapy. Alternative diets, such as Hay’s Food Combining Diet and Ayurvedic diet are also used for weight reduction.