A meal replacement drink is one intended as a substitute for a solid food meal, usually for purposes of weight loss

Weight loss

Weight loss, in the context of medicine, health or physical fitness, is a reduction of the total body mass, due to a mean loss of fluid, body fat or adipose tissue and/or lean mass, namely bone mineral deposits, muscle, tendon and other connective tissue...

. Often such drinks are in the form of a health shake

Health shake

A health shake is a blended drink intended to be, or marketed as being, healthy for one to consume. Slim-Fast is a prominent example. Bodybuilders sometimes drink a protein shake to help build and repair muscles. Some health shakes are intended as a meal replacement, often as a supposedly healthier...

. Medically-prescribed

Medical prescription

A prescription is a health-care program implemented by a physician or other medical practitioner in the form of instructions that govern the plan of care for an individual patient. Prescriptions may include orders to be performed by a patient, caretaker, nurse, pharmacist or other therapist....

 meal replacement drinks, which include required vitamins and minerals, include Optifast and HMR. Bodybuilders sometimes use meal replacements to save food preparation time when they are eating 5 to 6 meals a day.