Back in the days when slim fast meal replacement shakes first came out, everybody (including me) jumped on the band wagon to try to use it to lose weight. Needless to say, it didn’t work for most people. Why not? Because meal replacement shakes aren’t supposed to be used for weight loss (no matter what the slim fast marketing guy says!).
Not for Weight Loss
The single reason why meal replacement shakes suck at helping you with weight loss:
- Liquid based calories does not improve satiety, suppress hunger/appetite as well as solid calories of equal energy content. 
Some of these shakes may also include appetite suppressing ingredients such as hoodia gordonii, green tea extract, cocoa, but you can only fool your digestive system for so long until your ghrelin (hunger hormone) levels start to increase again.
I don’t know about you, but feeling hungry leads to a lot of dietary problems for me.
Don’t believe me? Check out the Rothacker & Watemberg study on solid vs. liquid calories claiming:
- “In conclusion, although the meal replacement diet bars contained only 30 additional calories than liquids, they provided an additional 2 h of hunger suppression from baseline that may have an impact on overall weightloss success. These results support superior short-term hunger control with solid meal replacements.” 
So how can all these companies claim that their shake can help you lose weight?
A lot of companies out there cite their own independent study which requires that participants eat well-balanced diets, and regular exercise in addition to taking meal replacement shakes.
I highly suspect that most people who follow the same regimen intaking the same number of calories, doing the same amount of exercise, without taking meal replacement shakes can achieve similar results.
What to Use Meal Replacement Shakes For?
If you take a look at the Shakeology nutrition label, a popular premium meal replacement shake out now, you’ll notice that their will notice that the the protein / carbs / fat ratio is about 1:1:0 In addition, Shakeology contains some vitamins and a bunch of fruit powder, probiotic, and enzyme blends. It macronutrient composition seems like a great candidate to replenish your glycogen store after an intense workout.
Personally, I’d throw in a scoop of whey protein per scoop of Shakeology only contains 17g of protein. YMMV depending on how much you weight and how intense your workout was.
I’ve chatted with a lot of skinny people who are trying to bulk up but can’t. The number one reason why they said gaining weight is hard is because they hate eating. They feel like eating is such a chore/hassle (I’m sorry but I can’t relate to this).
Since meal replacement shakes doesn’t help suppress hunger, they are ideal for people who want to gain weight and hate to eat. If you want to gain weight, try supplementing these shakes in between your meals, eat normally, and lift heavy @$$ weights and you’ll bulk up in no time.
- Tieken SM, et all. Effects of Solid versus Liquid Meal-replacement Products of Similar Energy Content on Hunger, Satiety, and Appetite-regulating Hormones in Older Adults. Horm Metab Res. 2007;39(5):389–94. [PubMed]
- Rothacker DQ, Watemberg S. Short-term hunger intensity changes following ingestion of a meal replacement bar for weight control. Int J Food Sci Nutr. 2004 May;55(3):223-6. [PubMed]