The Truth About Meal Replacement Shakes

It’s no wonder then that meal replacement shakes have become so popular – especially among people trying to lose weight. You simply throw them into a blender, mix and drink. You’re getting your nutrition in a matter of seconds, rather than having to wait for up to an hour or more.

Let’s face it – we’re all looking for ways to make life easier, and when it comes to preparing food, anything beats slaving over an oven at the end of a long hard day.

What do meal replacement shakes offer though over and above the convenience factor. Are they as good as their celebrity spokespeople claim – Shane Warne is pretty convincing – or do they come with potential hazards that act to counter the convenience of getting your nutrition fast? Let’s investigate.

Replacement Meal or Meal Ticket? 

New meal replacement shakes are constantly being launched onto an already over-saturated market. The most popular offerings over the last couple of years include:

Shakeology by Beach Body







Celebrity Slim

Do They Work?

Despite their various ingredients, all of these products work to assist weight loss on the basic premiss of reduced calories. If, for example, your normal lunch meal adds up to between 300 and 400 calories and then you suddenly switch to a 100 calorie shake, you will probably end up losing weight.

It is this calorie restriction along with the convenience of the shakes that makes meal replacement shakes so popular.

A number of studies have found that meal replacement shakes are more effective at losing weight than relying on whole foods for every meal. A meta-analysis of 6 studies led by Dr Steve Heymsfield found that test subjects who received a meal replacement, lost significantly more weight over both a 1 month and a 3 month period than those who ate whole foods. (7-8% compared with 3-4%).

What Are The Draw-Backs?

The human body was designed to eat and digest whole foods, not liquid food. The advantage of eating whole food is that it contains nutrients that interact synergistically with one another in our bodies. But when you take in isolated nutrients in the form of a meal replacement shake, you lose out on that combined effect.

In addition, there is a substantial thermic effect to eating food. It takes energy for your body to digest it. And that burns calories. And that will help you to lose weight. You don’t get this when you drink your calories.

Meal replacement products contain a whole host of ingredients. Some of them are unpronounceable. They are fillers and artificial sweeteners – and they are not good for you. Be sure to check the ingredient list of your meal replacement shake. If you come across three that you don’t recognise, put it back on the shelf.

The mere fact that you are losing weight on a meal replacement program doesn’t mean that you are losing fat. If the product fails to provide the protein that you need to sustain anabolism, you’ll be losing muscle tissue and water.

Potential For Over Eating:

Another potential problem with shakes is the potential for over eating. We are programmed to eat. Some experts believe that the fact that we are depriving ourselves of chewing and swallowing a couple of times a day means that we are likely to overeat during our other meals in order to compensate.

In addition, people generally feel fuller when they eat whole foods as opposed to drinking their calories. Often after drinking a shake, however, you still feel hungry and unsatisfied. That opens up the door for dangerous snacking between meals.

Because shakes are classified as a dietary supplement, they are not subject to the same regulations as whole foods. As a result, it is far easier for the marketers of these products to make unsubstantiated claims.

Bottom Line

Wherever possible, you should choose whole food calories. They will fill you up more, provide the synergistic benefits of food combining during the digestive process and ensure that you are getting real food into your system.

During the odd time that your day has gone to out of control and it’s either a meal replacement or junk food, reaching for that shake is your smart choice. Just don’t overdo it.


Int J Obes Relat Metab Disord. 2003 May;27(5):537-49.

Weight management using a meal replacement strategy: meta and pooling analysis from six studies.

Heymsfield SB1van Mierlo CAvan der Knaap HCHeo MFrier HI.

J Nutr. 2004 Aug;134(8):1894-9.

Nutr Metab (Lond). 2011 Sep 22;8(1):64.

Journal of the American Dietetics Association, 110;268-273,2010.