In the 1970s, “nutrition in a can” became widely used in hospitals and nursing homes to help nourish patients who could not eat or had difficulty eating solid food. Ensure was introduced by Ross Laboratories in 1973. In 1977, SlimFast was introduced to help with weight loss, sparking the use of meal replacements to address the obesity epidemic. And who can forget Oprah Winfrey, in 1988, pulling a wagon laden with fat across the stage to demonstrate her 67-pound weight loss on the Optifast plan? In the 1990s, Ensure and other drinks such as Sustacal, Boost, and Resource were marketed to healthy adults to supplement their nutrition. Since then, meal replacements have continued to corner the market, expanding to meet a variety of nutritional needs.
Meal replacements are beverages or foods that can be consumed in place of or as part of a meal. They provide a specific amount of calories, macronutrients (carbohydrate, protein, and fat) and micronutrients (vitamins and minerals). Some meal replacements are enhanced with other ingredients, such as special types of carbohydrate, probiotics, or herbs. 1
According to the article 2, a meal replacement shake contains fewer calories than the average meal, most people can lose weight successfully by reducing calorie intake.