Total Diet Replacements
TDRs, which include very low calorie diets (VLCDs) and low calorie diets (LCDs), are specifically formulated programmes that are based around formula foods that aim to replace the whole of the daily diet. These formula foods are nutritionally balanced with key vitamins, minerals, high quality protein, essential fats, fibre and other nutrients, and are designed to replace conventional foods for a period to facilitate optimal weight loss. They provide controlled energy intake lower than can be achieved with a reduced intake of normal foods.
VLCDs which contain less than 800 kcal (3360 kJ) are primarily aimed at those with significant weight problems (typically with a Body Mass Index (BMI) greater than 30) and encourage a greater initial weight loss, which has a great motivational effect. Their low energy level is intended to induce mild ketosis, which reduces hunger whilst effectively burning fat that can be used for energy.
LCDs, in turn, have a slightly higher energy content of between 800 kcal (3360 kJ) and 1200 kcal (5040 kJ) and are aimed at overweight people with a BMI greater than 25.
Both programmes are strictly regulated and provide guaranteed amounts of required nutrients. This gives them an advantage over ‘normal foods’ for those wishing to lose weight. It is almost impossible to maintain nutritional requirements through the consumption of ‘normal foods’ alone once daily consumption falls below 1200 kcal.
Formula-based programmes can be made into shakes or soups, rehydrated meals, bars, porridge, or desserts. There are also ready-to-drink options. Consumers beginning a TDR programme can select their daily meals from a range of products and according to their own personal tastes.
TDRs are carefully designed to take into account a large body of scientific research and should consist of compositionally sound food products that provide 100% of the Dietary Reference Values (DRVs)), including good quality protein and essential fatty acids. As they are specially formulated to ensure individuals are provided with adequate levels of essential nutrients, such programmes are far more effective than cutting calories through other conventional food combinations.