Low energy diets (LEDs) use daily energy intake targets 4200–7000kJ. This usually involves following a ‘prescribed’ diet plan such as those found on web-based programs or home delivered, pre-prepared meals. LEDs usually result in low to moderate adherence but can take the hassle out of planning and cooking meals.
For more info check this out: https://theconversation.com/health-check-whats-the-best-diet-for-weight-loss-21557.