Are meal replacement drinks actually healthy?

A closer look at the health claims behind these liquid meals.

Short read

May 20, 2025

Key Takeaway

A shake can replace a meal in a logistical sense, but it can’t fully replace what eating does for the body: satiety signals, chewing, microbiome diversity, and the full complexity of whole foods. Used strategically, meal replacements can support weight loss, blood sugar, and recovery—but used mindlessly, they can become another ultra-processed habit dressed up as wellness. The healthiest approach is treating them like training wheels: helpful when you need structure, unnecessary when your meals are already working.

If you walk through any pharmacy or grocery store, you might notice that meal replacement drinks are everywhere. In fact, they are more profitable than ever, and a whole new generation of them is targeting a whole new generation of people.

But are they healthy? Can they actually replace food? And beyond the marketing hype, what does the science say about them? Let's get to the bottom of the shaker bottle and try to answer every one of these questions.

Meal replacements and weight loss: an old story with new science

The first mass-market meal replacement was aimed squarely at American dieters as far back as 1959. Popular brands like SlimFast became household names- and remain on the market decades later- based on lofty promises of controlled calorie intake and effortless pound shedding. But do they live up to the claims?

Actually, and perhaps surprisingly, they seem to. Meal replacements have been studied more for weight loss than anything else, and many studies have confirmed that with support and under clinical supervision, they can be both safe and effective in this regard.

Fine print and final thoughts

There is a time and a place for replacing food, but despite all the possible benefits, there is no perfect substitute for the real thing. And to be sure, meal replacements are not all created equal. Many such products on the market are predominantly made of ultra-processed ingredients, often containing vegetable oils, synthetic emulsifiers, and problematic artificial sweeteners.

Moreover, while meal replacements are fortified with basic (synthetic) vitamins and minerals, they generally lack the full complexity of real food, including phytochemicals, antioxidants, and diverse fibre types crucial for balancing gut health.

In the final analysis, these formulas aren't inherently good or bad; they're tools, and their value depends on precisely what's in them and how we put them to use. The science makes it clear that when used strategically and with support, they can be powerful allies to support weight loss, metabolic health, and even recovery from illness or surgery. But we also shouldn't forget that in the end, food is profoundly complex, if not impossible, to replace. Balanced meals rich in diverse plants, healthy fats, and whole proteins offer sophisticated layers of health-promoting compounds far beyond the reach of product development.

Ard, J. D., Lewis, K. H., Rothberg, A., Auriemma, A., Coburn, S. L., Cohen, S. S., Loper, J., Matarese, L., Pories, W. J., & Periman, S. (2019). Effectiveness of a Total Meal Replacement Program (OPTIFAST Program) on Weight Loss: Results from the OPTIWIN Study. Obesity (Silver Spring, Md.), 27(1), 22–29. https://doi.org/10.1002/oby.22303

Ard, J. D., Neeland, I. J., Rothberg, A. E., Chilton, R. J., de Luis, D., Cohen, S. S., & Johansen, O. E. (2024). The OPTIFAST total and partial meal replacement programme reduces cardiometabolic risk in adults with obesity: Secondary and exploratory analysis of the OPTIWIN study. Diabetes, obesity & metabolism, 26(3), 950–960. https://doi.org/10.1111/dom.15392