The SlimFast diet is a commercial calorie limiting eating plan which first appeared in the late 1970s. The diet was at first a shake only plan but later incorporated SlimFast bars. The current version was modified in the late 2000s and uses the 3-2-1 format standing for three SlimFast snacks two SlimFast meal replacements and a well-portioned dinner.
The HMR diet is the creation of Lawrence Stifler, a behavioral psychologist who promoted the idea of meal replacements as a weight control method and boost for overall health. HMR stands for Human Management Resource and is a system where healthier alternatives are added to the diet in phases to achieve its goals. It is considered one of the most effective weight loss plans and physical activity is included as a key part of the program.