Meal replacement shakes are promoted as a healthy, quick solution for weight loss.
They are a high protein powders with other nutrients from juice extracts, freeze dried plants or vitamin and mineral mixes. They’re blended with ice and water, or with milks, fruits and veggies. They’re recommended to replace 1-2 meals a day, with a 3rd low cal meal plus physical activity.
There are many before and after pictures with testimonials of weight loss success. Anecdote is not evidence. Not many have been clinically studied, but we can get insight from other research with SlimFast or MediFast.
Science says that partial MR programs yield slightly more weight loss than low cal meal plans for the short term. It’s easy to follow a restrictive program for a few months, but what about a year or two or more down the line?
Researchers asked whether partial MR plans are more effective than diet alone after 1 year. They compiled 23 studies together. These partial MR programs included shakes, but also bars and pre-portioned whole food meals like Jenny Craig. After 1 year, partial MR programs yielded more weight loss than diet alone. Significantly more subjects achieved clinically meaningful weight loss using partial MR plus additional support. .
As shown in the study MRs can yield greater weight loss than diet alone when used as one tool among many within a supported weight loss program.
This interpretation is supported by the Academy of Nutrition and Dietetics, who stated MRs can be helpful for adherence to a low cal diet through portion control, convenience, limiting dietary variety and reducing problematic food choices. There is no one size fits all approach. However, only about 1/10 report using MRs, whereas 9/10 report keeping healthy foods at home, regular self weighing and physical activity.
When making major dietary changes it is best to consult a registered dietitian for individualized advice. The best evidence we have shows that partial MR programs can enhance weight loss at 1 year, though the they seem to be less important than other strategies as time goes on.
If you’re looking to shakes for weight loss, it’s important to incorporate additional healthy behaviors, like physical activity and healthy nutrient dense foods. Solely relying on shakes is not sustainable in the long haul.