The Problem With Meal Replacement Shakes (Liquid Protein)

Using meal replacement shakes to lose weight is a method that’s been around forever. At least if we’re talking about my 30-year-old life up until this point.

We’ve also seen them marketed as a means for maintaining health in the elderly – since we can pack them with protein and nutrients that 78 year old Gus, and 89 year old Gurtrude wouldn’t consume otherwise.  But should this be the message?

And more importantly, are these protein shakes and liquid meals really as beneficial as they’re portrayed?

If we’re talking about a product like BOOST, the answer is simply NO. As the ingredient list makes it look like a product at McDonalds.

And sure, there’s the protein, but it’s from Soy! And with 28g of sugar, corn syrup and vegetable oil, the old folks are better off skipping a meal.

ENSURE isn’t much better, with 18g of sugar, the same corn syrup and less soy protein – at 9g. But not to worry, they make up for it with soybean oil instead of canola.

The fact that these beverages are marketed to seniors as health products, and recommended by medical professionals to be consumed daily is ludicrous!

When we’re talking about a standard whey protein powder for the elderly, the conversation is slightly different. Although, we end up with the same question that should be posed to individuals looking to ‘lose weight.’

“Why can’t you eat real food?”

For the majority of the weight loss crowd, meal replacements shakes are used as a controlled starvation tool – to keep them away from food, and help them lose drastic amounts of weight. But as discussed in Eat Meat And Stop Jogging, this is a horrible method for losing because you end up gaining it right back.

And yes, it’s better than juicing because of the protein (1, 2), but it’s just another quick-fix, quick-failure that teaches you nothing about proper eating, and leaves you prone to gaining (and struggling to lose) for years to come.

In a 2011 study in the New England Journal of Medicine, a 10-week period of restricting calories resulted in reduced leptin levels (increases hunger, lowers satiation) for a FULL YEAR after the restriction period.

One of the major benefits of eating protein is the energy cost that comes with digesting and absorbing it; which is approximately 20% higher than what it is in carbohydrates and fat.  Meaning, people that eat more animal protein expend more energy, whether they’re exercising or not (1, 2, 3, 4, 5).

Further, they tend to consume less energy, or have a lower desire to consume, since protein kills the appetite quickly, and keeps us satiated longer (1, 2, 3, 4, 5). Largely because of the slow breakdown and release of energy, but also because of the lower glycemic index (when it’s consumed as the meal or consumed with a meal). Since it prevents the sharp spike and drop in blood sugar we see with rapidly digested carbohydrates.

But serve that same protein dose in liquid form and things look a lot different. Whether we’re talking whey protein, casein protein, rice protein, pea protein, or soy protein (please don’t consume that last one by the way). As the energy cost (thermic effect) is lower, because digestion is already taken care of; and the energy demand (hunger) is higher, because the absorption is instant, and there’s a spike in insulin that’s no different than high-glycemic carbs.


In a 2012 study in the journal Obesity, researchers found that 80% of those consuming liquid meals were hungry after 2hrs of eating, compared to only 5% of those consuming a solid meal (with the same macronutrient composition).

So, aside from mucking up your metabolism, the problem with liquefying meals is that you’re essentially processing them. Eliminating the fibrous materials you should be working to digest, and sending the amino acids directly to your bloodstream. This hyperinsulinemia and blood sugar roller-coaster is not good for your health or body composition, and this non-existent digestion (or gastric production) is not good for your gut. No matter how skinny you get, and how bad you need the protein.

Or put another way, food is perfectly designed for us to thrive. Leave it the way it is, and eat it the way it is, and you will be rewarded. But try to cheat the system, and your health and body composition will suffer.

Now, or in the future.

Stay Lean!
Coach Mike


The Deal With Dairy

Why Juicing is Stupid?

More Protein = Less Hunger

Are You Eating Enough Protein?

Nothing Sweet About Sweeteners

Eat More Meat. Burn More Fat. Period!