I Replaced Dinner with a Meal Replacement Shake for 2 Weeks — Here’s What Happened

Most of us have very busy schedules and are usually drained by the end of the day, leaving us with no energy to cook healthy meals. This is when the late-night pizza cravings arise and those ‘I’ll just grab something quick to eat’ turn into calorie bombs.

As someone who has been in the fitness game for almost two decades, I can completely understand this struggle. I won’t lie; I constantly have to battle against the evening munchies.

Recently, I felt like it was time to make a change, and I swapped my usual dinner with a meal replacement shake.

Full disclosure, I also used this as an opportunity to address my curiosity.

The sports nutrition market is constantly being flooded with new meal replacement supplements, and I see many people adopting these products. But do these supps actually work? I wanted to test their efficacy firsthand.

In this article, I take you over how replacing my dinner with a meal replacement shake for two weeks impacted my hunger levels and weight. I’ll also share tips on how you can try this challenge for yourself if you’re trying to lose weight by ditching the day’s final meal.

Setting the Stage: Preparation and Planning

Choosing the right meal replacement shake could make or break this two-week challenge.

I’m pretty choosy when it comes to supplements, and I wasn’t settling for some chalky, bland concoction in the name of a meal replacement shake. I was hell bent on choosing the high-quality shake with a balanced nutrient profile.

Since I was on a bulking phase when I started this two-week challenge, I made sure my meal replacement shake had a healthy dose of protein, carbs, and fats. Plus, it is very easy to overlook the bigger picture when buying a supplement, which can lead to nutrient deficiencies. I have been in this industry long enough to know better.

I thoroughly investigated the micronutrient profile of my supplement to ensure it was ticking all the right boxes.

Get into the habit of checking the labels for a comprehensive blend, covering essential nutrients like vitamin D, B vitamins, and iron. Also, the meal replacement supplement gets brownie points if it contains electrolytes.

I’ll not be revealing the name of the brand I used because I feel that would make this article feel like a product review rather than an experience-sharing piece. However, I would say that you should look for brands that are third-party tested to ensure better quality standards.

Plus, what worked for me might not necessarily work for you. The right supplement for you will depend on multiple factors, including your current fitness levels, nutritional needs, and transformation objectives.

I chose dinner because it fits my lifestyle and it allowed me to control my calorie intake in the evening, when I am typically less active. If you are looking to try this challenge, pick a time that works best for you.

Meal Replacement Shake Recipes

Remember, you do not have to limit yourself to supplement powders during this experiment. I added variety to my meal replacement shakes by adding other ingredients. Here are my three go-to recipes:

Chocolate Peanut Butter Power Shake

Try this recipe if you have a chocolate-flavored meal replacement powder:

• 1 scoop whey protein isolate (chocolate)
• 1 tablespoon natural peanut butter
• 1 cup unsweetened almond milk
• 1/2 cup spinach
• Ice

Berry Blast Shake

This is an absolute must-try if you’re using vanilla powder:

• 1 scoop plant-based protein (vanilla)
• 1 cup mixed berries (frozen)
• 1 cup water
• 1 tablespoon flaxseed oil
• 1/4 cup of oats

Green Machine Shake

Opt for this if you are an endurance athlete and a fan of greens:

• 1 scoop of casein protein (vanilla)
• 1 cup of kale
• 1/2 an avocado
• 1 cup of coconut water
• 1 tablespoon of almond butter
• Ice

Week 1: Initial Adjustments and Observations

I was a little anxious going into this challenge as I had never skipped dinner before. Although drinking a meal replacement shake isn’t ‘skipping,’ not eating real food felt like a big challenge.

Nonetheless, this anxiety was short-lived as I felt full and satiated after drinking the shake. Meal replacement shakes can be notoriously thick. At one point, I contemplated eating my shake with a spoon. Okay, I’m exaggerating a little bit, but I hope you get the point.

The Convenience Factor

One thing stood out as soon as I was done with this ‘meal.’ The shake was incredibly easy to prepare as all I had to do was mix it in water. It saved a ton of time, allowing me to spend more time with my family and read a book before calling it a night.

I just wish preparing real food was just as easy.

One big unexpected benefit of this challenge was that my cravings were completely wiped out. I believe it has something to do with the delicious meal replacement shake recipes. After all, who craves something after drinking a berry blast shake?

Surprisingly, my energy level remained stable in the evenings, even though I expected a crash. Plus, the shakes were easily digestible, ensuring I had no bloating or discomfort. This helped me fall asleep faster.

One week is too early to expect any significant results. I had added 500 calories to my daily intake to pack on lean muscle tissue, and I ended up gaining a pound at the end of the seven days, which is decent progress in my opinion.

At this point, I should also mention that this diet shift required significant adjustment. I had to decline every dinner invitation during these two weeks. First, I wasn’t sure if restaurants would allow me to bring my shaker bottle, and I didn’t want to be ‘that’ guy who drank from his sipper while others ate like normal humans.

Week 2: Deep Dive into the Effects

Once my body had adapted to this new dinner routine, it was time to shift gears.

The shake kept me feeling satiated for three to four hours, which was good enough that I felt asleep comfortably.

Honestly, there were a couple of days during the second week when I craved eating real food. I had never realized that the act of chewing food could have such a big psychological impact when it came to satisfaction after eating food.

Furthermore, I realized that replacing my dinner with a meal replacement shake required me to adjust my other meals. I increased my vegetable and lean protein intake during lunch to make up for the shortfall.

I had to get a little creative in the second week to ensure a successful bulking phase, and I added a scoop of casein protein to my meal replacement shake to spike its protein content. The great thing about casein is that it is a slow digesting protein, meaning it helps keep untimely hunger pangs at bay. (1)

Results of This 2 Week Challenge

I felt much lighter after transitioning to a meal replacement shake. This improved my sleep quality and quantity as my body didn’t have to work too hard to digest the food. I woke up feeling refreshed and energized, and my overall mood improved, empowering me to get more done throughout the day. (2)

Replacing my dinner with a shake helped recalibrate my perception of portion sizes. Even after completing this challenge, I inclined towards eating smaller portions during dinner and even during other meals. This can be a game changer for people who tend to overeat.

I ended up gaining 2 pounds by the end of these 14 days. Although the gain wasn’t substantial, I noticed an improvement in my body composition as I lost body fat and gained lean muscle. My clothes now fit better, with the shirts feeling loose around the waist and snug around the shoulders and biceps, a sign that I was moving in the right direction.

Remember, adjusting your calorie intake according to your transformation objectives is the most important thing while starting a new diet. Use a calorie deficit, which involves burning more calories in a day than you consume, to lose weight. Conversely, eat more calories than you expend to gain weight or add muscle tissue. (3)

I’d add that eating light (or rather drinking) significantly improved my mood, focus, and mental clarity. The nutrient-balanced shakes ensured that my brain received a steady supply of nutrients to function optimally.

Long-Term Considerations and Recommendations

Even though a suitable meal replacement shake helped me hit my calorie and macronutrient targets, I wouldn’t recommend it as a long-term solution.

You are more than welcome to try this challenge for a week or two, but replacing dinner with a shake for a lifetime would be overkill.

Remember, they are called ‘supplements’ for a reason.

You must prioritize nutrient-dense whole foods in your diet, as they are packed with macro and micronutrients. Plus, they are rich in fiber, which can improve your gut health, digestion, and nutrient absorption.

Most supplements have several ingredients, like fillers and flavors, which can hamper your gut microbiome over time, severely impacting your digestive system.

Furthermore, your body adapts to your diet. If your shake lacks sufficient calories or macro nutrients, your body will compensate for it by slowing down your metabolic rate, which can hinder your performance.

Meal replacement shakes are perfect in specific situations. For example, athletes on tight schedules may benefit from a quick, nutrient-dense shake. However, folks with ample time on their hands should not make them a part of their lifestyle.

Meal replacement shakes should be an absolute no-go if you have an eating disorder, as they can worsen the condition.

Finally, learn to listen to your body. If you experience persistent fatigue, digestive issues, or any other adverse symptoms, reassess your approach and make the necessary adjustments as soon as possible.

Conclusion

Replacing my normal dinner with meal replacement shakes turned out to be more convenient than I had originally planned. It helped me gain two pounds of lean muscle tissue within two weeks without causing any significant negative impacts like untimely cravings and hunger pangs.

Unlike me, you don’t have to go cold turkey on your regular dinner overnight. Start small by drinking a meal replacement shake once a week. Increase the frequency as your body starts adapting and you feel more comfortable.

If you have any questions about replacing your dinner with a meal replacement shake, post them in the comments below, and I’ll be happy to help!

References:

1. Kim J. Pre-sleep casein protein ingestion: new paradigm in post-exercise recovery nutrition. Phys Act Nutr. 2020 Jun 30;24(2):6-10. doi: 10.20463/pan.2020.0009. PMID: 32698256; PMCID: PMC7451833.
2. St-Onge MP, Mikic A, Pietrolungo CE. Effects of Diet on Sleep Quality. Adv Nutr. 2016 Sep 15;7(5):938-49. doi: 10.3945/an.116.012336. PMID: 27633109; PMCID: PMC5015038.
3. Kim JY. Optimal Diet Strategies for Weight Loss and Weight Loss Maintenance. J Obes Metab Syndr. 2021 Mar 30;30(1):20-31. doi: 10.7570/jomes20065. PMID: 33107442; PMCID: PMC8017325.

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