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Slim Fast Exposed 2023 [MUST READ] - Does It Really Work?

Want to lose weight but not sure where to start? Here's one of diet convenience mainstays.

Top Rated Diet Shakes of 2023
What is it?

Slim Fast is a meal replacement shake said to be clinically supported to help keep weight off. It’s offered in 4 distinct flavors including creamy chocolate, strawberries & cream, vanilla cream, and caramel latte.

It’s said to help control hunger for a total of 4 hours, and it’s made with 20 grams of protein and just 1 gram of sugar. This ready to drink shake is made without any gluten or lactose, and the company offers it in many retail stores. Is this meal replacement a good option for weight loss? What kinds of effects are customers experiencing? In this full review you’ll see what Slim Fast truly has to offer. Discover the top 10 diet shakes by clicking here.

Do You Know the Best Diet Shakes of 2023?

Slim Fast Ingredients and Side Effects

Here are the ingredients to their creamy chocolate flavor:


Calcium Caseinate

Milk Protein Concentrate

Canola Oil

Cocoa processed with Alkali


Cellulose Gel

Natural and Artificial Flavors

Potassium Phosphate

Mono and Diglycerides


Potassium Citrate


Soy Lecithin



Sodium Citrate

Citric Acid

Caramel Color

Magnesium Phosphate

Sodium Ascorbate

Calcium Phosphate

Vitamin E Acetate

Zinc Gluconate

Ferric Orthophosphate


Calcium Pantothenate

Manganese Sulfate

Vitamin A Palminate

Pyridoxine Hydrochloride

Thiamin Mononitrate


Chromium Chloride

Folic Acid


Sodium Molybdate

Potassium Iodide


Sodium Selenite


Sweetened with non- nutritive sweetener


Milk Protein Concentrate:  A processed form of milk protein that loses its minerals and liquid. It’s spray dried and treated as a cheap and longer lasting alternative to regular milk. 

This ingredient has been used controversially, since around 70% of it is imported from countries with different safety standards.

The Food and Water Watch group has released a statement on this ingredients lack of safety:

“MPC’S are largely unregulated”

There are concerns of this ingredient being contaminated with melamine. This ingredient is considered harmful if swallowed, and it’s also known to irritate the skin.

It's believed that pasteurization is able to kill contaminants; this is why the FDA allows this ingredient to be imported in. Though the Food and Water Watch Group argues this isn’t enough, and that things like melamine are still found and cannot be pasteurized away.

Potassium Phosphate: Typically given as a medication to help balance out the amount of calcium that’s in the body. It makes urine more acidic and is used to help prevent kidney stones.

Possible side effects may include:

  •  Headaches and dizziness.
  •  Nausea and vomiting.
  •  Diarrhea.

Sucralose: A non-caloric artificial sweetener that is up to 1,000 times sweeter than average sucrose.

The Journal of Toxicology and Environmental Health did a study on rats. They found many damaging effects including:

“increased fecal pH and enhanced the expression of P-gp”

“exerted numerous adverse effects, including reduction in beneficial microflora”

Damaged microflora can have serious health consequences, such as reduced immune function and increased inflammation. It’s also known to cause symptoms of depression.

P-gp or glycoprotein is a found in the cells membrane, and it makes sure that any potential contaminants are filtered out of the body. So according to this study, sucralose is considered a toxic ingredient when in the body.

Carrageenan: Thickener and binder found in red seaweed.

A study on mice showed that this ingredient could cause tumors. The Cancer Letters published a clinical study that showed major damage:

“degraded carrageenan is carcinogenic to the colorectum of the rat”

This effect was seen in just small doses of this ingredient.

Artificial Flavors: A man made synthetic ingredient used to mimic the taste of real flavors. It can be made from many different foods and it’s unknown where Slim Fast sources their ingredient from.

This ingredient is a cheaper alternative to more wholesome and real additives.

Caramel Color: A food coloring made from treated carbohydrates.

It can be extracted from many common allergens, though it’s unknown where Slim Fast sources this ingredient from.

This is a highly processed ingredient that is specially treated in order to provide a color to drinks.

Slim Fast Quality Of Ingredients

When judging a meal replacement shakes, it’s important to look at the quality of the sweeteners and protein. The protein added to Slim Fast comes from cheap sources in milk protein concentrate and calcium caseinate.

Milk protein concentrate in particular has been shown to be heavily processed and potentially contaminated.

The added sweeteners sucralose and a nonnutritive sweetener which is never explained are also added. Though sucralose provides just 1 gram of sugar to this mixture, it’s been shown in studies to cause tumors. It also is treated as a toxin within the body, according to respected clinical studies.

There’s also a total of 180 calories added, which is exceptionally higher than other meal replacements. When looking to lose weight, it’s important to keep calories as low as possible in order to prevent weight gain.

Overall, the quality of ingredients is poor. There are artificial flavors, artificial sweeteners, and cheap protein added. In this top 10 list are the very best meal replacements.

EDITOR’S TIP: Combine this supplement with a proven meal replacement such as 18Shake for better results.

The Price and Quality of Slim Fast

No official price is set by the manufacturers, but they do offer an interactive map showing the approved vendors.

An 8 pack of their chocolate sells for $14.16 on their Amazon.com page.

Since each shake is a full serving, around a month’s supply or a 32 day serving would be $113.28, if taken twice a day.

This is expensive for what are a cheap protein, and a blend of artificial ingredients. Though the sugar is low and the protein and fiber is high, it’s important to look at the ingredients to help determine the overall quality.

Too many artificial ingredients are added to suggest this would be a good brand to replace a meal.

There’s also no listing of the amino acid profile, so it’s unknown how well rounded the protein is. Amino acids are important since they provide support for many important body functions.

The company makes suggestions that up to 4 hours of appetite suppression are possible. They fail to offer any proof of these claims. It’s unknown if this is backed by any real studies, or it it’s a suggested number.

There was an issue with contamination in the past. The Associated Press reports:

“recalled all canned Slim Fast drinks because of the possibility of bacterial contamination”

“could cause diarrhea, nausea, and vomiting”

This 2023 recall was approved for all cans of Slim Fast, and it’s unknown exactly how this contamination was started. The manufacturers failed to provide any evidence that this issue wouldn’t happen again.

Business of Slim Fast

Information on the company practices aren’t explained on the official website.

The company name is also called Slim Fast. Here is their listed contact information:

Phone Number: (800) 754-6327

There are currently a total of 39 negative reviews against the company on their Consumer Affairs listing. This is due to their changed formula which sells for more but it’s offered in smaller portions. Also, people were disappointed with the lack of customer support.

EDITOR’S TIP: For the best results with meal replacement shakes diet our experts recommend to use it at least 5 months. Save your money buying a few bags of meal replacement product.

Customer Opinions of Slim Fast

Many reviews are available online, here’s what a few customers have had to say:

“my stomach began to get bigger”

“seems like it put weight on me”

“tastes like your generic, low-calorie protein shale”

“didn’t find this had the “four hour hunger control” it claims to have”

People mentioned how the taste was terribly artificial, and that it was hard to drink each bottle.

Weight loss was also missing for some customers, while others added how they actually gained weight even with diet and exercise.

Some side effects were also listed including nausea and ill feelings.

Appetite suppression was also lacking. For many customers, there was a lack of any benefits in drinking these shakes.  The best options for weight loss are found in this top 10 list of meal replacements.

Conclusion - Does Slim Fast Work?

When making a decision on Slim Fast, it’s important to look past the supplements facts label. Though this shake does have a high amount of protein and fiber, as well as low sugar and lots of vitamins and minerals, it’s what’s truly inside what counts.

This shake has a combination of artificial sweeteners, artificial flavors, and a high amount of calories which might make weight loss harder. That’s why so many customers have mentioned that they not only failed to lose weight, but some actually increased in size.

This shake also uses a cheap protein source, with ingredients like sucralose which have been shown to cause tumors in clinical studies. Much better solutions exists which are made only with all natural and wholesome ingredients.

The very best meal replacement of 2023 offering all the necessary criteria for weight loss is 18Shake. This meal replacement has a high quality mixture of whey protein which is easy to digest, and well balanced in amino acids. It’s also made with a high amount of fiber, and low sugar. That’s why so many users have mentioned it’s a great solution for weight loss. You can find these impressive testimonials on their official website.

18Shake  also has no binders, fillers, or artificial ingredients. All you get is a high quality formula made to help suppress appetite and increase weight loss. It’s even backed by a great 30 day money back guarantee. That’s why so many users keep coming back to this comprehensive meal replacement.

How Does Slim-Fast Compare?
  • Product Name
  • User Rating
  • Has Good Appetite Suppressant
  • Has Only Natural Components
  • Good Taste
  • Slim-Fast
  • 27 /100
  • .

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User Feedback

(Page 2 of 7, 127 total comments)


The key to dieting is to burn more calories than you eat...sticking to a diet is all about commitment. if you eat a low- cal breakfast, lunch, and dinner and excercise after you eat dinner. You will lose weight. Also setting a time when you are going to stop eating for the day like 7pm or 8 pm works!

posted Feb 8th, 2011 12:50 am



I lost 5 pounds in 2 weeks!

posted Feb 7th, 2011 6:49 pm



I'm on day 2. Not felt hungry yet because of all the snacks and water. Before I would skip breakfast, starve for hours then stuff my face until my buttons burst. This is teaching me to eat regularly and get into the habit of breakfast. If I lose weight along the way then great! :)
The chocolate shake is so thick and yummy. Cereal meal bars are slightly expensive but when put into the context of how much I would spend on a mac donalds meal, it's really not that bad. Only downside which doesn't bother me, but I know it would for others, is a little extra gas. He he...

posted Feb 1st, 2011 7:54 pm



Slim-fast has survived for a reason! I realy shouldn't, but I'm addicted to Coffee, so I think if I laid off the coffee I may be able to lose more weight. I do drink my water every day. I try for at least 32 oz of pure water per day along with natural fruit juices and my coffee.

I tried one week to go without my coffee, my head just hurt too bad. I had to run back to it like a kid missing their blankie

posted Jan 18th, 2011 8:54 pm


Does anybody know what is the amount of aspartame they put in the sakes if any? is any of the products aspartame free? Iread the label but it does not say anything. But the website tells you that they use aspartame which is a terrible poison, that worries me.

posted Jan 11th, 2011 7:09 pm



I use it. I love it.

posted Oct 22nd, 2010 3:33 pm



I'm on day 3 i drink the water and snacks are fruits. Headaches started today. I exercise everyday for 30 min on the eliptical but still haven't lost anyweight at all

posted Sep 23rd, 2010 9:55 am


As with any diet you can't just go back to eating fast food. I see people who lose the weight then stop exercising regularly. Or they lose the weight & then are at the cheesecake factory pigging out. Of course you gained it back. I am on day 2. I know when I complete this I will have to stick with something like 2 boiled eggs for breakfast, a grilled cheese & salad for lunch, & skinless chicken breast for dinner. It's common sense. Just because you lose the weight doesn't mean you can go back to eating poorly.

I have the strawberry & creme shake & the chocolate shake. I love them & I am not one for chocolate either. I can't even drink a whole one. I have to force myself to finish it on my breaks at work. I am not using the Slim Fast protein bars. I am using the kellogg's protein bars& I eat 2 a day instead of 3. Then a sensible dinner.

I did miss the chewing action today so I replaced 1 bar with 2 hard boiled eggs. It did the trick for me.

What more important? being healthy or eating stuff mushrooms & a 28 ribeye steak. Now in the future if i want to pig out I will do it on the weekend & I will skip 1 shake & 1 protein bar. ( 400 calories ). When I go out I will put 1/2 in a box & leave it at the resturant ( don't take it home!! ) & eat a 900 calorie meal. That way I can get some of the food I like without going over my calorie intake.

posted Sep 9th, 2010 2:05 pm


The headaches come from aspartame. a diet drink sugar substitute. diet coke gives me a headache too. but we have to loose weight so we deal witht he problems related to diets.

posted Aug 21st, 2010 9:43 am


I started Slimfast just yesterday and i am SOOOO hungry but i know i have to stick to this. I am starting to get headaches though?? Any idea's why? I did go cold turkey on this!
Thanks for any advice and stay on it slimfaster, were in this together :)

posted Aug 17th, 2010 2:52 pm



I'll echo what Brandi said - you have to drink the recommended water or you will feel hunger. The slim fast kinda acts like a sponge in your tummy and makes you feel full. I've lost 10 pounds in July!!

posted Jul 30th, 2010 12:08 pm



Very easy and I like there are alot of flavors. Iget them at sams alot cheaper than the store and then I never run out!!

posted Jul 30th, 2010 12:07 pm



I tried the slim fast diet a few years ago and I loved it. With moderate exercise 2-4 times a week I lost 15 pounds in less than 3 months. As a fitness/nutrition-aholic I highly recommend this for someone who needs a set eating itinerary. Since that diet I've educated myself on every type of diet/nutrition info and I work out everyday. I still use the slim fast shake powder for breakfast or post workout and the meal bars for when I am on the go at school. Slim fast is not one of the diet fads that die out quickly because it actually works. Anyone looking to lose should definitely try it!

posted Jul 14th, 2010 3:30 pm



So I tryed this diet many moons ago and lost weight. I just turned 45 and need to lose mucho weight. If something worked for me before why not try it again. I think that all diets can work if you stick with eatting right and working out. For those people that say they did't loose weight it is because you ate to many calories.(right) .I'm no fool.I too did the same.A wonder why i did'nt loose weight. So anyhow 1st day on my way to feeling healthy! I'll will be weighing in every week. So I'll let you know how it is going. Lolaa

posted Jul 8th, 2010 1:47 am


Just started the Slimfast 321 today so Im looking for a suppot forum and feedback to motivate me

posted Jul 3rd, 2010 9:24 pm



I have been on SF 321 plan for a week now. I even had a few pieces of chocholate but still managed to lose 2 lbs in a week. I haven't increased my exercise either. I'm going to follow it to a T and report back in 1 week. Only difference is no cheating and I'm going to drink 8 glasses of water a day and I'll see if I lose more than 2 lbs. Wish me luck. Currently 161 - goal 140.

posted Jul 2nd, 2010 10:48 am


Starting the slim-fast 1 2 3 in the morning. I weigh 148# need to loose atleast 20# will keep you posted.

posted Jun 10th, 2010 10:10 pm


PLEASE HELP! Quick questions:

I was on Slim Fast for a little over two weeks and didn't lose anything! Not even inches. In fact my clothes got tighter! I worked out about 60-90 minutes a day five-six days a week. I'm baffled and so upset. I went on Slim Fast about ten years ago and I lost weight quickly on it. But that was just the drinks and not the bars with them. I have the Slim Fast high protein shakes. I heard there were different shakes but this is all I have seen in my store. Any of you use these shakes plus the bars and it worked? I also heard it was high carbs and maybe that's why it doesn't work...but it works for others so I don't get it. Anyone see weight loss each week on this or nothing until the end of the month and then you saw the weight drop/gone? I stopped doing this since I am so frustrated. Can anyone help?

Thanks for your time and help! :)

posted Jun 10th, 2010 4:17 am



I like the slimfast 3-2-1 plan because you can change it up so much. The website has GREAT ideas for snacks that are not even slimfast products, but fit into the plan. For instance - shake for breakfast, non fat yogurt as a mid morning snack, meal bar for lunch, an apple as a mid-afternoon snack, a normal meal (chicken breast, roast potatoes, broccoli?) and half a cup of nonfat frozen yogurt for an evening snack :)

posted May 27th, 2010 9:56 am


do you know why it works so well? Because your only eating 1160 calories a day. Adult females females if you over 51and are sedentary should be eating at least 1,600 calories a day. I didn't just make that up it's on the American Heart Associations website. go there to find out how much you should be eating. because this plan will not give you your recommended amount. now I'm not a health grue, nutritionist, or heath teacher, but I did the math and honestly this is not the right way to lose weight. this is quick weight loss by depleting your nutrition, real weight loss comes from life style changes.

posted May 22nd, 2010 3:36 pm


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QUICK FACTSQUICK FACTS Start the Diet Now Advertisement
  • Established: 1977
  • Founder: Daniel Abraham
  • Headquarters: Unilever in Unilever House, London
  • Stock Symbol: UL
  • Accessibility: Retailers and drug stores
  • Diet Type: Meal replacement through shakes, bars and snacks
  • Gender: Male, female

Do You Know the Best Diet Shakes of 2023?


Slim-Fast made its name with meal-replacement shakes. But today it has expanded into a complete weight loss plan complete with an array of products and an organized weight loss plan.

By lending convenience and simplicity to its dieters lives, it has grown its product offering to include bars, snacks, smoothies, as well as a meal plan called Slim-Fast Optima, which provides a healthy combination of complex carbs, protein and healthier fats. For those watching their carb intake, there is a low-carb option and a low-sugar option.

The Slim-Fast plan offers 100 percent of the nutrients your body requires and typically has women consuming 1,200 calories daily. Weight loss is supported by the low-caloric intake. The Slim-Fast plan allows you to use both their products and your choice of nutritious foods to promote healthy weight loss.

Slim-Fast outlines a four-step approach to weight loss: Portion control, sensible eating, regular physical activity, and support.

By sticking to the plan, you can lose 10% of your body weight in the first six months at a rate of one to two pounds a week.

  • Convenience of food products for people on the go
  • Variety of flavors to choose from
  • Realize actual weight loss
  • Calorie intake isn't unsafe
  • Named #3 in the Best Commercial Diets by US News, 2011
  • As with all packaged food plans, the cost will be more than if you prepare all of your own meals
  • Contains aspartame

There are a variety of ways to mix-and-match the Slim-Fast foods with your food choices. The Slim-Fast plan involves six small meals/snacks every day. You are advised to use Slim-Fast products for two meals and one snack daily.

The rest of the day, you're on your own to choose healthy meals when eating out or cooking at home. No calorie counting is necessary and no foods are forbidden; you can still eat your favorites. However, lean protein, fruits, and vegetables are emphasized.

Their meal plan might look like this:

  • Breakfast is a Slim-Fast Smoothie with six ounces of fat-free yogurt.

  • Lunch is a Slim-Fast Shake or Bar, in addition to a whole-wheat english muffin topped with marinara and low-fat mozzarella.

  • Dinner will be your one meal with no more than 500 calories. For dinner, divide your plate in fourths- half should be vegetables, one-quarter protein and one-quarter starch, along with a salad or fruit.

While following the Slim-Fast plan, be sure to drink plenty of water and commit to regular exercise.


The Slim-Fast website has a thorough exercise support system that you can customize to your needs and desires.

It is recommended that you exercise 30 minutes a day to receive optimal results.


Slim-Fast is one of the "veterans" in the prepackaged weight loss solution arena. They're popularly known for their meal replacement shakes, but that doesn't mean you are restricted to a liquid diet. Mix and match their products with regularly prepared healthy food, and busy people like you can find healthy weight loss success.

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