The SlimFast 3-2-1 plan is designed to be easy and convenient. You should replace two meals a day with a SlimFast meal replacement and your third meal should be a healthy, nutritious meal of 600 calories for a female and 800 calories for a male. SlimFast recommend that you have up to three snacks a day to help keep you feeling satisfied between meals. You can choose between a tasting range of SlimFast snacks for convenience, fruits or vegetables – all less than 100 calories. In total the plan is designed to deliver a total intake of between 1200-1400 calories per day. In addition, you should aim to drink between 1.5-2 L of water per day. It is also important that whilst on the plan you aim to do 30 minutes of moderately intense physical activity each day.