Are Meal Replacements Good for Weight Loss?

Cindy Ma
by Cindy Ma
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Are Meal Replacements Good for Weight Loss?

Quick, effortless and portable, meal replacements are convenient when you can’t be bothered to cook. But, that’s not the only reason why they dominate grocery store shelves. Precise quantity and nutrition partnered with a guided eating plan make meal replacements appealing for those looking to lose weight. Do they work? Let’s take a look.

Could you forgo meals and live on a solely liquid-and-bar diet?

Soylent thinks you can. As one of the latest meal replacements to hit the market, Soylent touts its products as being “engineered to provide all the protein, carbohydrates, lipids, and micronutrients that a body needs to thrive.” Each Soylent drink provides 400 calories, 20 grams of protein and 20% of daily essential micronutrients (based on a 2,000-calorie diet) — you could theoretically drink five bottles and be set for the day.

Although not intended for weight loss, there are some who look toward Soylent to lose weight and have found success. That said, it is important to note that if you’re able to create a calorie deficit, you will lose weight regardless of the meal replacement program followed.

Back to Basics: What are meal replacements?

Meal replacements, often in the form of shakes and bars, are typically made with controlled amounts of calories and nutrients. With different purposes and target markets in mind, all meal replacements are not made equally. For example, SlimFast presents itself as a weight-loss product to be taken as a low-calorie meal. Ensure and Boost market themselves as nutrient supplements to fortify the diets of those who have trouble eating enough. Soylent appeals to anyone who wants to think less about food but still get in all their essential nutrients without excess (namely sugar, salt and fat). Here’s how they differ nutritionally:

SlimFast Creamy Milk Chocolate (11 fl. oz./325 mL)
Ensure Milk Chocolate (8 fl. oz./237 mL)Soylent Drink (14 fl. oz./414 mL)
Total Fat6 g6 g21 g
Carbohydrates25 g33 g37 g
Protein10 g9 g20 g
Fiber5 g1 g3 g
Sugar18 g15 g9 g

SlimFast is made high in fiber and protein for prolonged satiation. Ensure and Soylent are made to be nourishing and, thus, contain a higher calorie count and more micronutrients.

So, can meal replacements help you lose weight?

Based on a 2003 systematic review pooling data from six randomized controlled trials, the answer is a cautious yes, with major caveats. In those trials, 487 people were randomly assigned to either a partial meal replacement diet or a traditional reduced-calorie diet. Both groups lost weight after three months. At a one-year follow-up, 74% of those following diets partially supplemented with meal replacements and 33% of those following reduced-calorie diets had lost 5% or more of their initial body weight. However, the two groups ate a broad calorie range — between 800 and 1,600 calories a day — and the authors were affiliated with meal replacement companies. Hence, these results should be viewed with caution.

The Verdict

Plain and simple, relying on meal replacements misses the mark on so many levels. Meal replacements are temporary and bound to be tiresome over time; it is difficult to maintain weight loss with such a strict lifestyle. Instead, cultivate long-term healthy behaviors for a more sustainable method of weight loss.

Additionally, there is so much more to learn about nutrition, especially regarding the roles of phytonutrients and antioxidants found in food — it’s impossible to find all the nutrients our body craves in lab-formulated meal replacements. At best, they deprive us of the basic gratification of eating; at worst, they rob us of the social connection we have with others through food (Think: birthday parties and weddings).

While you may see weight-loss results, a diet solely relying on meal replacements is not the best strategy for long-term weight loss and maintenance.

Have you tried meal replacements? If so, share your thoughts below.

About the Author

Cindy Ma
Cindy Ma

Cindy holds a bachelor’s in nutritional science from UC Berkeley. By sharing her knowledge of nutrition, Cindy aspires to empower others to reach their full potential by living a healthy lifestyle and embracing a positive body image. She enjoys experimenting in the kitchen, exploring cultures through food, and exercising with friends. Connect with her on Twitter.


35 responses to “Are Meal Replacements Good for Weight Loss?”

  1. Avatar dscardella says:

    I am using Almased which is soy, honey and yogurt. I have 2 a day. Which meals replaced varies. I eat what I want for 1 meal and have low carb snacks. I have lost weight ‘painlessly’. I am a ‘eat to live’ and not a ‘live to eat’ person. So, this doesn’t bother me and I eat ‘treats’ when I wish.
    I needed to lose weight because of a sudden and permanent more sedatary life. I was actually the correct weight for my height and doctor liked my bmi. It is easier on my legs to have less weight. Excersize is extremely limited and has to be no impact.
    The bottom line with these products is why you are using them and the person themselves. I never started with the full 3 a day the products suggest.
    I used Slimfast years ago and had no problem keeping weight off for 25 years until recent events.

  2. Avatar Steph says:

    Um… Soylent Green is all I can think of. Did they name it that on purpose?

  3. Avatar Nevertoolate says:

    I am morbidity obese and am on isagenix shakes. I chose this route because i need a strict regime. Some days i wish i could just eat normal but know because of my binge eating habit that wouldnt be good for me until i get a hold of my blood sugars, and get some much needed counseling. Its been 3 weeks and have lost 14 inches and feel great.

    • I design nutrition plan to lose weight, to stop binge eating, my website is not fancy, I experienced hijacking , now it is secure. There is different ways to treat binge eating. Face to critical obesity, I prefer using fat burning food, using the patient reserve, to deliver energy, it works medically well, especially with high blood sugar .

    • Avatar Liane Laskoske says:

      Good work on the progress! I use Isagenix and have lost 40 lbs. This is my 2nd year using it. It is a journey, and Isagenix is a great program. Keep going!

    • Avatar SKS74 says:

      I also use Isagenix! Love it! Lost 20lbs in my first 10 wks. I’m about halfway to my goal and I feel so much healthier from the inside out! The nutritional aspect of it is head and shoulders above the ones listed above. The MRS are delicious and don’t get me started the bars -So good!! Lol. Deciding to adopt this nutritional system is one of the best decisions I’ve ever made. 🙂

    • Avatar Kaz says:

      I started taking a tablet from the health food store and it has been a huge help. I went in asking for something to stop sugar cravings and settled on this. It was very cost effective. And it works for me. Made by “fusion health” its 30 tablets called “blood sugar” for around $20. I wont go without it now. I have one as early as 10am then another about 3 in the afternoon and i find thats all i need to take away those nasty nasty, ‘I want to binge’ cycle. And believe me, it takes ALOT to stop me from having that sweet cake/biscuit/toast/bread/muffin/cake/chocolate. If it could help anyone else as much as it has me, that would b great.

  4. Avatar Calories In vs Calories Out says:

    I don’t believe in a blanket statement for anything. I started dieting in May 2013. Just counted calories (limited to the minimum 1200) and walked everywhere I possibly could. I lost 12.5kg in just under 5 months – no crazy fast shedding of pounds, just slow and steady. To make it easier to stick to my calorie count for the day, my lunch consisted of a meal replacement shake of 270 calories. That was my saving grace, purely because I knew it contained a high % of the vitamins and minerals my body needs everyday, and I would know exactly how many calories to budget for dinner and breakfast. I quickly saw where my problem areas were with regards to food, and learned to live without any sodas. I still occasionally eat crisps and I couldn’t get rid of chocolate, that diet would never last. I updated my eating habits – slowly and over time, not all at once – and when I took a break from dieting for a year and a half (and went off the shakes), I didn’t pick up any of the weight again, except right at the end where I went on an exquisite island holiday and overindulged on cocktails leading to a 2kg gain. I am now on my second round (which I started right after my holiday) and 7kg down, still using shakes as a replacement for some of my lunches. I am slightly less dependent on them now as I am in control of my meal sizes and cravings, but for that first round I would not have managed without the shakes.

    Basically, every person is different. What should be addressed is the idea that a shake is a miracle cure, and the lack of education surrounding calorie counting and taking responsibility for your eating habits.

  5. Avatar Denise says:

    I start my day with a Slimfast smoothie made with 1% milk and supplemented with a raw egg blended in. I have an Atkins Meal Bar around 11a and again around 3p. my last calorie intake of to day is a 2% Greek yogurt around 7p. I drink 2-3 glasses of V8 throughout the day and no less than 64oz of water. I am losing an average of 3lbs per week and feel great. Once I hit my goal weight (13 more pounds). I will eat a “real” lunch instead of bars and reintroduce social eating into the mix with an awareness of and adherence to portion size. I will also continue to hold myself accountable by continuing to utilize My Fitness Pal. For me, it’s too easy to mindless graze on snack foods if I do not track through documentation of my food and beverage intake.

  6. Avatar Shaman Romney says:

    I’ve been on a soylent only diet for about a month now as a challenge. I have felt great, but the mental discipline is a hard thing. I’ve lost weight as well, and over all I would suggest people give the product a try. The nicest thing about soylent is that it is nutritionally complete, so it makes a good supplemental food source for vegans and other restricted diets. I think long term I’d be fine, but mentally it will be nice to have some variety.

  7. Avatar Bea says:

    I’ve been doing the slimfast 321 plan for the last 55 days minus a few off days. I’ve lost 30lbs. I have a shake for breakfast along with a weightloss supplement and garnola bar. Same for lunch except I don’t have the supplement and I eat a Salad around 200 calories. My final meal of the day is about 500-600 calories. Keeps me right around 1200 calories everyday.

    I like the simplicity of the shake. I loathe thinking about what I want to eat vs what I have vs what I have time to make. I have 2 kids and need to keep moving. I’ve had trouble in the past simply dieting by calorie counting. I’ve found slimfast shakes much easier to stick to. This time, I feel like I can actually reach my goal, which is 50lbs away.

    • Avatar Jess D says:

      In order to reach your weight loss goal faster you might consider having your large meal in the middle of your day and then having your supplement and salad at night. Studies have proven that if you consume most of your calories between breakfast and lunch you’ll have a greater weight loss success.

  8. Avatar Joseph says:

    I have been drinking Beachbody’s Chocolate Meal Replacement Shake for 7 years (unfortunately, now discontinued) but it works like a champ. Used it every morning for six months and I went from 230 lbs. to 175 with its help and of course a proper nutrition schedule and a gallon of water and hardcore workouts six days a week. When done with a proper fitness and nutrition routine…it works great.

    • Avatar Wade Dillworth says:

      Joseph, great results! And I agree with your statements, except for the BB MRS. Never used them, but another MRS with similar results. If you’re interested in a quality MRS, send me a PM

  9. Avatar daathrock says:

    In addition to overhauling my complete diet..I incorporated Spirutein and Swanson Green Max as my breakfast replacement..breakfast foods have always been my downfall…in the past year I have lost 90lbs by doing this and no exercise…now that I have disciplined my eating habits, I have started Intermittent Fasting.. 5/2 and this past week I have started walking 45mins per day and being very successful…I am slowly weaning off the Spirutein, using it for cravings and on IF days…

  10. Avatar Wade Dillworth says:

    I agree with some of this and disagree with some as well. Example: “….if you’re able to create a calorie deficit, you will lose weight regardless of the meal replacement program followed.” I agree. If you’re able to create a deficit, you can loose weight regardless of what you eat.

    A comment I don’t completely agree with:
    “Plain and simple, relying on meal replacements misses the mark on so many levels. Meal replacements are temporary and bound to be tiresome over time; it is difficult to maintain weight loss with such a strict lifestyle.” No one should rely on MRS as their only source of meals. MRS used as your morning meal, combined with a healthy lunch and dinner does not place a restriction on your lifestyle. And to say it is “bound to get tiresome over time” is a personal opinion. I know you could only review a limited number of MRS, but there are better quality MRS available.

  11. Avatar Virginia Zam says:

    “Meal replacements are temporary and bound to be tiresome over time; it is difficult to maintain weight loss with such a strict lifestyle.”

    I totally disagree worth this statement. I have had an atkins dark chocolate shake for breakfast ever since they came out (ie. Years), i don’t vary the flavor, I love the convenience and they lay me until lunch. The only time I alerted my routine was the 2 years I used wonderslim mocha shakes to get to my ideal weight and maintain. Although I started out using a variety I soon settled on mocha pudding shakes — up to 7 per day for at least a year and a half.

    Making blanket statements like that makes me question your credibility. There are many people all over the world who crave routine not variety.

  12. Avatar Debbie says:

    Hi I have been using Garden of Life Raw MR. I am a senior. Makes losing weight more of a challenge. I have not lost any but I have not gained.
    I have salads with protien for lunch and a salad and protien for dinner. I walk for exercise. (Bad knees). I have 40lbs to lose. Can’t tell if the MR is helping or not

    • Avatar SKS74 says:

      Hey Debbie! If you are interested in hearing about an awesome system of MR etc that is specifically geared toward healthy aging (as well as reaching and maintaining ideal weight) please let me know! I’d be happy to share the info with you! You can PM me or email 🙂

      • Avatar Debbie says:

        Hi SKS74
        Have been feeling much better using an MR. More energy, And I get my Vitamins. Still hoping for weight loss but not much.
        I think my water intake is too low. Will start tracking that also. I think for someone older like me an MR is a good choice.

  13. A weight loss program, depends on the weight to lose, the timing, the support you have etc Recently I learnt that a personal contact, lost 100lb in 2 years after asking me question, he design his own diet and chose his own MRS. I designed meal replacement for patients , friends and family, always different, but efficient to get results in a short period of time, good if the recipient is able to continue with a healthy diet.

  14. Avatar Kym says:

    I have used Cambridge Weight Plan and lost near enough all my weight but I like this diet because it slowly weens you off the shakes and back onto a healthy, balanced diet in order to creat a new mindset, 6 steps in total and ways of keeping it off and maintaining.

  15. Avatar Zach Brown says:

    Soylent is not a “meal replacement”, it is simply a full meal, in liquid form. If you look at the nutrition info presented in this article, the differences become clear. The meal replacement drinks listed have only 200 calories per bottle, which is not enough and will not keep you full as long as a 400-calorie meal. And take a closer look at the sugar numbers! Soylent is designed to be nutritionally complete and, as they say, something you could consume exclusively if you chose to. (Most Soylent users do not) If you were to have 400 calories of one of these other drinks, you’d be having nearly 4x as much sugar! That is totally fine every once in a while to replace a meal, but drinking lots of those is in no way healthy.

    You say that a person can “theoretically” survive off of 5 Soylent bottles a day, but it’s not theoretical. It has been, and will continue to be done. And those who do so generally report feeling better and healthier, sleeping better, having more energy. The same is not true for people living exclusively off these other “meal replacement” drinks. Even the study you mentioned, you noted that the people involved still only had a partially replaced diet.

    You also claim that it is impossible to get all the nutrients our bodies need from one drink. But you don’t have any research or scientific data to back this up. You may or may not be right (In fact, it is likely that you are correct, on a literal level) But the Soylent team has provided as much evidence as they can that their drink is sustainable and nutritionally complete, and if you want to discredit them, you need to provide your own evidence to the contrary, rather than just stating it is impossible without any backup. The truth is, it is very likely that Soylent does not contain every single thing the body needs. But I’m even more confident that the diets of 99% of the users on this site also do not contain everything the body needs! Chances are that for most people, the Soylent does have better nutrition content than their average meals, unless a person is really eating healthy, balanced, homecooked meals with fruits and vegetables for the majority of their food.

    I just don’t think the “verdict” here makes sense with the rest of the article. You noted that Soylent claims their drink is nutritionally complete, you noted that studies have shown that these drinks can be viable, but your verdict is to avoid them. It seems to me like your verdict is less of a conclusion based on the evidence, and more just a personal opinion. You also say that drinking these is not sustainable, but that is just not true. I know many people who have been drinking Soylent for months or years and still rely on it. It’s not for everyone, but it’s just incorrect to say that they are not sustainable as if it is a fact. (Though, if you were talking exclusively about the slimfasts and the ensures of the world, I would probably agree. But as I said, there is a difference between these “meal replacements” and what Soylent is.)

    And to clarify to anyone reading this who hasn’t heard of Soylent before:
    – It is NOT a weight loss drink. It is simply a meal containing complete nutrition. But it is filling and it has an exact calorie number, and since weight loss is mostly about monitoring calories, it is useful for that.
    – Soylent is designed to replace as many or as few meals as you want. Only a minority of people replace every meal with it. Many use it for just breakfast. Some use it for breakfast AND lunch. Some eat normally, but grab one only on the days when they don’t have time to prepare a meal. Etc.

    • Avatar Lew says:

      Thank you for explaining this so well. I love Soylent (and I just subscribed to their other drink Coffiest) but it’s not fair to compare it to SlimFast without additional explanation.

      • Avatar Zach Brown says:

        No, thank you! I was worried I’d come across as a raving lunatic defending Soylent haha, I am really glad to know someone appreciated it. =)

  16. Avatar Kathryn G Platten says:

    I’ve used optifast which did help me lose weight but like so many of these shakes/ meal replacements they are full of sugar and fructose and don’t help your cravings or long term weight loss! I’ve found better success with trying to reduce sugar intake to below 30g low carbohydrate and having good protein and good sources of fat. Lost nearly 9kg in 10 weeks. 🙂

  17. Avatar Dee says:

    I slimfast. I lost 5lb my first month and 5.5 my next month. Sure it’s full of sugar and people judge but it’s what works for me.

  18. Avatar Gabrielle Person says:

    I drink Boost Rich Milk Chocolate shakes for lunch, mainly on work days. I have for years (Slimfast before that, though once they dropped the sugar the taste was awful and I had to switch). I love the flavor. It has quite a few benefits for me and yes, I have lost weight. First, 240 calories. I’m sure a sandwich would have more and not as many nutrients. This lower calorie intake means I have more room for other meals and a couple snacks in my calorie budget each day. Second: nutrients: Boost has lots of vitamins and minerals and 3 grams of fiber. Third, time: I can drink that shake in 2 minutes. I don’t need to take my lunch break for that. So I break up my 30 minute lunch break into 3 walking breaks to get the bulk of my 10k Fitbit steps each day. I’ve lost 32 pounds between my calorie budget and walking. Now the shakes and the Fitbit are helping me maintain this healthy weight i’m now at. The shakes alone didn’t help me lose weight. They help in saving calories and time for walking.

    • Avatar Tina says:

      Good point about the shakes helping save calories and time not help lose weight. Without good food habits and exercise it’s not going to stay off. Everyone is busy and its an excellent way to get fuel for the day without spending all the time in the kitchen preparing meal. Trying to cram 26 hours into a 24 hour day is tough. I like your schedule for getting exercise in during lunch break. Right now I use mine for running errands but should try to get in more steps for the day.

  19. Avatar Tina says:

    I did a lot of research before choosing a MRS. The one that kept coming up on top of the lists for best taste was Idealshape shakes and had some of the best review ratings in general. So I use idealshape shakes as my weight loss MRS. They taste awesome. I’ve tried several flavors and chocolate would have to be best. (tastes like a good thick chocolate milk or maybe cold hot chocolate.) I’ve used it off and on for the last 2 years. They contain hunger blockers that helps keep you full for about 3 hours. And they are around 100 calories each. Also for convenience and being on the go it is also great. My husband uses them for the convenience aspect of it so he doesn’t have to think about cooking while I am gone.

  20. Avatar Kia Crawford says:

    I feel like I must have missed a section of this article. Perhaps editing butchered it?

    The jump from tentative data confirmation to a conclusion that says it’s not a good idea is abrupt and not at all something that I feel like I can trust. If you want me to believe that meal replacement shakes aren’t a good idea you need to show me how they do somewhere other than your personal opinion in the conclusion.

    Your data doesn’t support your conclusion. Rookie mistake.

  21. Avatar kirnkorner2001 says:

    My wife and I started with ViSalus shakes almost 4 years ago now (Nov of 2012 was when we started). It was a huge springboard to make small steps to a healthy lifestyle. I have lost 175 lbs and she’s lost 162 lbs so far; and are both hoping to hit 200 lbs lost before the year’s end. We were both super morbidly obese at the beginning, and now we are doing things that we never thought we’d be able to do. It’s been a fantastic 4 year journey!

    One of my biggest tips to anyone starting a journey: take it small steps at a time. If that means starting with a shake a couple or few times a day (like we did), then do that. That will lead to other changes in time.

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