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Optifast Review - 13 Things You Need to Know

Optifast is a weight loss program that tries to include a healthy lifestyle, like diet supplements, meal replacements, medical clinics, and more. The plan promises weight loss and a decrease in waist circumference. However, ingredients like sucralose and canola oil haven’t been shown to do have any of those benefits.

Our research team looked into the program’s scientific claims, “patient journeys,” and medical monitoring. In the end, our team compared Optifast’s published success stories and weight-loss contests to the customer reviews to see if this is the plan for you.

Optifast can be purchased through their Official Site.

Optifast Readers: Noom is offering our readers a risk-free trial, for a limited time. Click here for more information!

What is Optifast?

What is Optifast

Optifast is a company brand created by Nestle Health Sciences that provides weight loss programs for people who have a high BMI (30 or greater) who are obese or overweight.

While they currently don’t have a BBB page, their parent company Nestle USA has an “F” rating. They’ve been in business for 86 years, which is a long time to drum up complaints. But, in the past three years only 39 complaints have been closed and five in the last 12 months. The reason for the F rating is “failure to respond to 26 complaints filed against the business,” claims the Better Business Bureau.

The Optifast weight management system requires Optifast shakes and meal replacement foods such as bars and soups. Their programs claim to be for the overweight, people of most ages, teens, and people who plan to undergo weight loss treatments.

The programs are also comprehensive, which means that doctors, psychologists, and other health professionals are involved in the weight reduction journey of each person enrolled in the Optifast system. An Optifast meal plan consists of a liquid diet, including Optifast shakes.

Typically, you’ll follow the diet for at least four weeks. The timeframe makes it easy for almost anyone to follow. Weight loss from this eating plan results from eating a very low-calorie diet (VLCD). Optifast is a VLCD option for those seeking immediate help with their body weight.

  • International Journal of Obesity – Very-low-calorie diets promote weight loss, but research shows that consuming up to 1200 calories per day is just as effective as 800 calories per day – based on a comparison of a VLCD to a low-calorie diet.
  • International Journal of Endocrinology & Metabolism – If you’re looking for improvements to things like blood sugar and cholesterol, rapid weight loss tends to show more favorable results. However, body composition is more improved in people who lose weight more slowly.
  • International Journal of Behavioral Medicine – Overall, it appears that, as long as a person is considered healthy enough to adopt a strict diet and is being followed up by a healthcare professional, a very-low-calorie diet is an effective means of weight loss.

Optifast Competitors

Ideal Protein
Other similar products: , Serious Mass, Isagenix
What Does It Do?

What Does Optifast Do?

The Optifast weight management system may help people lose weight in a short period. Different age ranges are available and programs created specifically for people undergoing some weight loss treatments. Dieters on any one of the Optifast programs must consume primarily Optifast products during the diet’s main phase, which may last over six weeks.

The three Optifast phases include:

  • Active weight loss
  • Transition
  • Maintenance

Active Weight Loss

The patient visits the clinic, where the doctor runs tests and prepares a custom program. During the Active Weight Loss Phase, you’ll follow an Optifast full meal replacement diet.

Active 2 – In this phase, you will consume:

  • 3 OPTIFAST VLCD products
  • 2 cups of low starch vegetables
  • One teaspoon of vegetable oil
  • providing less than 800 calories per day

In 1983, research showed that very-low-calorie diets – at or below 800 calories, were safe. Still, that weight maintenance is a problem that needs to be addressed after goals are achieved, or as the dieter resumes a higher-calorie diet, according to the Annals of Internal Medicine.

Jump forward to 2017, and research shows the same results. This time published in the European Review of Medical and Pharmacological Sciences, authors shared that “our results show the efficacy of VLCKD with synthetic aminoacidic protein replacement, for the reduction of cardiovascular risk, without the development of sarcopenia and activation of inflammatory and oxidative processes.” In this case, the diet was ketogenic, so carbohydrates were limited, but it reinforces the idea that diets of 800 calories can be completed safely, but how effective are they at long-term weight loss?

The International Journal of Clinical Practice published an article in 2014 that covered a 3-year outcome survey to “determine the effect of a very low-calorie diet (VLCD).” The research found that as long as the dieters followed up with “group-based behavior therapy on weight-loss and long-term weight management,” they were able to maintain weight loss long-term.

There’s even research that a VLCD can work as a treatment for obesity in the aging population, according to the Journal of Gerontology.

This phase lasts about 12 weeks. However, you’ll receive weekly monitoring. An additional benefit is the weekly group meeting.


The second phase (also known as Active 1 Phase) is the transition phase. It lasts about six weeks and slowly begins adding in regular foods. You’ll continue to attend group sessions.

In this phase, you will consume:

  • 1 Optifast VLCD Product
  • Two low-calorie meals (approximately 400 calories each)
  • at least 2 cups of low-starch vegetables
  • Two serves of fruit
  • One serve of dairy
  • providing 1000-1200 calories per day

Long-Term Weight Management

The Maintenance Level, all Optifast VLCD products, are eliminated, and the focus is on maintaining your weight loss.

The dietary intake consists of:

  • Three low-calorie meals (approximately 400 calories each)
  • Two serves of fruit
  • One serve of dairy
  • plus low-starch vegetables

The dieter exercises and practices good eating habits learned throughout the program. Dieters eat regular food, Optifast meal replacement meals, and a benefit is the ongoing support from Optifast.


Optifast Ingredients

Optifast Ingredients

Optifast offers several different products. However, the Optifast Method relies on meal replacement shakes more than other pre-packaged foods. Some Optifast ingredients include:

  • Milk Protein Concentrate
  • Soy Protein Isolate
  • Maltodextrin
  • Vitamin
  • Minerals

Milk Protein Concentrate

There are various milk-based protein powders to use in Optifast shakes, but research says milk protein concentrate may not be the best choice. Based on a 2017 study in the Journal of Food Science and Technology, milk protein concentrate has poor solubility. If not properly dissolved, protein powders can leave a grainy feeling in the mouth.

Soy Protein Isolate

According to the journal Nutrients, “soyfoods have long been recognized as sources of high-quality protein and healthful fat.” Also, soy has been shown to help with mood and skin health, among other more serious medical conditions. Though there has been concern over the safety of isoflavone use for some individuals because of the potential hormone-like effects, authors claim reports of side effects are mostly present in animal studies, “whereas the human research supports the safety and benefits of soyfoods.”


“Maltodextrins (MDs) are a class of carbohydrates (CHOs) extracted from a range of botanical sources. They are industrially produced by enzymatic or acid hydrolysis of the starch, followed by purification and spray drying,” says Critical Reviews in Food Science and Nutrition. There are two types of maltodextrin – easily digestible and not-so-easily digestible. We don’t have any indication as to which one is used in Optifast shakes.

If the maltodextrin is added as a source of fiber or as a prebiotic, which would be a good thing, it could change this product’s dynamic.

Vitamins and Minerals

If you take a morning multi-vitamin, you may be concerned about using a product that’s enriched with even more vitamins and minerals. However, the reason these are added to meal replacement shakes is to mimic the vitamins and minerals present in whole foods. There’s no way to 100% duplicate what’s missing, so a generic amount is often added.


Optifast Benefits

Some concerns regarding the Optifast programs and products have surfaced from time to time. However, there are some key benefits to using Optifast diet plans, including:

  • Weight loss
  • Nutritional support
  • Easily prepared meals
  • Maintenance support for long-term results

Optifast diet plans are only comprehensive diet plans that provide medical support, nutritional counseling, and meals. Other weight management systems may provide medical and nutritional counseling, but they won’t provide the actual food that the dieter needs to eat.


Optifast Results

Optifast Results

Optifast results occur when the dieter lost weight and improved overall health and wellness. The Optifast programs are primarily for health purposes and not just physical shape or numerical weight. A person who has gone through the program and has signs of improved health is considered a success.

Side Effects

Optifast Side Effects

The Optifast diet plans are may be more supportive in many ways than other diet plans. By checking in with their physician, psychologist, and dietitian frequently, Optifast dieters are more likely to stay on track and avoid any risks associated with weight loss. However, the risks that may occur whenever a person starts a diet like this include:

  • Nausea
  • Upset stomach
  • Irregular bowel movements
The Optifast Diet

What is the Optifast Diet?

The Optifast Diet is boasted as “the serious solution for weight-loss” and claims to be suitable for adults and teenagers with a body mass index (BMI) of 30 or greater. This is a medically supervised program that’s intended to help with weight reduction and overall health. It typically lasts for 26 weeks and may be partnered with a weight-loss surgical procedure. This program involves:

  • Meal Replacement Diet
  • Medical Supervision
  • Lifestyle Education
  • Counseling
  • Ongoing Personalized Support

Optifast Directions

Since Optifast diet plans aren’t the same for everyone, each person will have different directions that they need to follow. They’ll need to follow the guidelines established by their physicians and dietitians throughout the main dieting phases.

Most dieters consume around five shakes per day and maybe even a few snacks, but the caloric allowance will depend on the user’s weight and health.


What is the Optifast Cost?

The cost of the entire Optifast diet program may run upwards of a few thousand dollars. The price includes visits to Optifast clinics, applicable tests, therapy sessions, and nutritional counseling. Also, meal replacement products vary in cost as well.

For example, an Optifast shake can cost between $21 and $80. Considering the dieter can only eat or drink Optifast products during the first phase, this may get expensive fast. There are also additional costs associated with the Optifast. There are reports of a monthly fee, a starting fee, and service fees.

Moreover, the price varies depending on the goals of the person. However, some consider Optifast products not budget-friendly. You can contact the company directly for specifics relating to price.

On their website, you can find a clinic near you by entering your zip code. From there, you may be able to learn more about potential costs.

Customer Service

Customer Service Information for Optifast

Their customer service team is available Monday – Friday: 8am to 8pm, EST.

Email addresses: optifastmarketing@us.nestle.com and info@optifast.com

Phone Number: +1 800-662-2540

Address: Nestlé HealthCare Nutrition Consumer and Product Support 445 State Street Fremont, MI 49412



Does It Work?

Does Optifast Work?

Does Optifast Work

Optifast uses a non-traditional approach to weight loss. While great for some, it’s a challenge for others. The Optifast diet restricts calories to a certain degree. While this may cause weight loss, some find it challenging to follow such a very low-calorie diet.

Assuming a person is ready to start the program and finds a clinic nearby, the diet is still very intensive and will require a lot of time off work or school for medical appointments. This may also be a deterrent to success and may cause people to quit halfway through. Some of the ingredients used in Optifast products are also questionable.

They may not prevent the dieter from losing weight, which is the program’s primary purpose. Perhaps the best way to get a better idea of whether Optifast works is to look at some Optifast user reviews.

The Optiwin Study

The OPTIWIN study is a 52-week open-label, randomized, controlled clinical trial that assessed the safety and efficacy of the Optifast weight-management program.

In the OPTIWIN study, the Optifast group comprised 135 participants who followed a total meal replacement plan for 16 weeks. The meals were made up of 40% carbohydrates, 40% protein, and 20% fat. Traditional foods were introduced gradually after 16 weeks.

The food-based group comprised 137 participants who followed a reduced energy diet that adhered to the Diabetes Prevention Program guidelines.

Both groups exercised vigorously for 150-180 minutes each week. They also attended behavioral counseling sessions.

The Optifast group lost twice as much weight as the food-based group. The mean weight loss for the Optifast group was -12.4% compared to -6.0% for the food-based group. Optifast participants saw greater reductions in fat mass(30%-64% vs. 12%-42%) and waist circumference(p=0.011 vs. p=0.0011) as well.

What Users Are Saying

What Users Are Saying

“This has been a great protein shake. The flavor is delicious and I have not felt the least bit hungry after having one of these. I am using these as a meal replacement and have lost 20% of my weight so far!”

“Tastes great and works when trying to suppress hunger. Also works when dieting and using in between meals. So many more flavours which is a bonus. Would recommend.”

“I’ve been using this product alone for my Optifast program, and I don’t get tired of it. Good consistency, quick to gel, and a good mouth feel.”

Bottom Line

The Bottom Line on Optifast

Optifast is one of the few medically-supervised weight loss programs shown to work. Aside from customer reviews, some studies show its effectiveness. Once you dial in your diet, exercise and supplementation, there’s a chance you’ll lose weight.

Weight management incorporates diet, supplementation, and exercise. When it comes to supporting systems and weight-loss apps to fit your lifestyle changes.

Among the best weight-loss programs we’ve seen is called Noom. Packed inside is a plethora of support to help you reach your goals and keep the weight off. The unique resources include expert articles, human coaching, personalized support and more. We’ve never come across a clinically proven weight-loss app, so we had to pass this one along to you.

The team supporting Noom is offering a free trial offer as a sign of confidence in their program.

Learn More About Noom »
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What is the Optifast diet program?

Optifast is a very-low-calorie diet consisting no more than 800 calories a day.

What are the side effects of Optifast?

According to the company, Optifast side effects may include:

  • Irritability
  • Bad breath
  • Fatigue
  • Headache
  • Hair loss


Does Optifast work?

Many people have had success with Optifast. However, there are no studies available that prove that you will lose weight using this program.

How much weight can you lose on Optifast?

Because Optifast is a very-low-calorie diet that’s medically-supervised, rapid weight loss is likely. Weight loss of up to 5 pounds a week has been reported.

How much does it cost to do Optifast?

The cost of a bottle of Optifast varies, considering this is weight-management program. Some users reported paying $100-150 a week, while others found the cumulative cost of he program, extra food, and more cost around $3,500 for four months.

Where can I buy Optifast?

Optifast can be purchased using their Official Site.

Can you drink coffee on Optifast?

Yes, both coffee and tea are allowed on Optifast. You should only consume 3-4 cups of tea and coffee per day. Avoid dairy, sugar, and alcohol while on this program.

The program does suggest you drink 2 liters, or 10 large cups, of water every day.

Can you eat eggs on Optifast?

No, eggs are not part of the Optifast diet. You’ll eat mostly vegetables and salad partnered with Optifast shakes.

Do you need a prescription for Optifast?

Optifast doesn’t require a prescription since it is classified as a “food for special medical purposes.” You will need to see a special clinic, where a medical provider will assess whether or not the program is right for you.

Is Optifast covered by insurance?

This depends on the insurance company, level of coverage, and state. Contact your provider prior to beginning the program to find out what they cover.

How many Optifast shakes a day?

You are required to drink at least four Optifast shakes a day. How many you’ll drink depends on the specifics of your program.

Is Optifast right for me?

Optifast is best for patients with a BMI of over 30. It is recommended only as part of a comprehensive treatment program.

What can you eat with Optifast?

Optifast allows for a variety of food. Some of the more notable vegetables that are allowed include green beans, alfalfa sprouts, eggplant, bean sprouts, cucumbers, bok choy, celery, cauliflower, carrots, capsicum, brussel sprouts, and cabbage.

Can diabetics have Optifast?

According to the official website, most type 1 and 2 diabetics that are overweight or obese are eligible for the Optifast program. It can also adhere to the guidelines for gastric bypass surgery prepration.

Can you exercise on Optifast?

You can exercise up to 30 minutes a day while on a very-low calorie diet like Optifast.

What is the difference between Optifast and Optislim?

Optifast is a medical weight-loss program, while Optislim is a line of Australian weight-loss food.

200 Optifast Reviews

  • Does the product contain wheat?

    Does the product contain wheat?

    • Roca Welch

      No, the products do not contain wheat.

  • My daughter lost 14 pounds.
    diane (Verified Purchase)

    my daughter has been doing this for a month and only lost 14 pounds also she is starting to have double over stomach pain…why is that?

    • hs

      14 pounds is a lot in 4 weeks. Tell her to keep it up!

    • Cynthia

      She is losing at a good pace.

    • Larry

      Make sure you are including some benefiber-type product for bulk in your diet. Could be constipation related. Benefiber is more expensive but you can buy a house brand at CVS that is more reasonable.

    • Kathleen

      Eat prunes5/6aday

      • Lori

        Do NOT eat Prunes ! they are full of sugar! Buy some sugar free Metamucil.

        • Cindy

          Thank you for that little reminder duh I need to take mine out of the refrigerator now

    • Roca Welch

      Optifast is a medically supervised program. Call her doctor immediately. She could have a gallstone problem.

    • Carol

      She may be experiencing pain in her gall bladder. She may have to have surgery to remove it.

    • Cindy Coffman

      I’ve been reading everybody’s comments about the gallbladder. I was on Optifast many years ago and ended up in the hospital with gallbladder issues. Although the issues went away and I also lost 60 pounds while on the diet. I would have her checked out just to make sure.

      • Lucinda

        Years ago I to lost 20 kilos in 3 months then intense pain and a gallbladder full of stones. I had to have it removed. Apparently fast weightloss no matter the diet can cause this.

        • Anonymous

          what happen did you remove it or not

  • Why feeling side effects?
    mlavenia (Verified Purchase)

    I just started optifast yesterday.Today, after slight exertion I found myself sweating profusely and not feeling good. Prior to eating I did a fingerstick and it was 157, the highest its ever been fasting. Can anyone explain why this happened?

    • kathy

      I’m a diabetic also. When I started Optifast my doctor warned me that my blood sugar could bounce all over the place initially since I stopped all diabetic pills when I started Optifast. I have been lucky and my blood sugars have been between 94 and 113. Give it a little time and you should level out.

    • Stacia

      Wondered if Mlavenia could share w/us the cost of the program. If it’s REALLY expensive I’m not going to bother making an appt @one of their clinics!

      • Cindy

        The way I look at it depends on what you spend on food for your household and how much you eat but and maybe a few dollars extra than what you spend normally but which is way worth it!

    • Anonymous

      How much sugar is in each shake? That would easily raise blood sugar. Especially without the added fat to slow digestion.

  • R the ready to drink shakes soy based or lactose free

    R the ready to drink shakes soy based or lactose free

    • Jan

      Short answer, no. They contain milk products and all contain about 1gm of lactose, except for the vanilla powder, which contains 8-12 grams of lactose.

      • Angela

        Eat Pork!

        • sue

          I just my first 2 weeks on the opti-fast 900. So far its been 3 days, anyone finding 4 shakes a day hard? I know I am, there are so filling. Plus I have to drink tons of water. I hope the weight loss starts soon.

          • rocco

            I just did my first weigh in lost 10 lbs first week. I know the people who say they lost 20 lbs in a week are lying. no way. I followed this to the letter. not one thing did I eat I wasn’t told to. 3 shakes , one soup I bar. I never heard of losing twenty lbs in a week. stone cold lie to the people on here don’t listen to the people who are lying. The program is good. little hard, the meetings are good. Don’t get down if you don’t lose twenty lbs in a week. that is a person who is lying. its impossible to do.

            • kim

              My husband lost 18.5 lbs the first week! Me, only 9. Figures!

            • Elizabeth

              Everyone’s metabolism and body fluids are different. You did a great job for yourself and YOUR journey. Don’t criticize someone else’s journey. They may have more weight than you to lose. Be kind and encouraging.

            • Anonymous

              I lost 14.2 my first week. I think it depends on how big you are

            • NikkiD

              I would imagine it would depend on several factors. Age, starting weight and exercise are a few. Younger folks lose faster.

            • Lily G

              no not a lie as it is different for everyone.

            • Michelle

              I lost almost 15kg in the first week and average 3k a week now. I dont know thr pounds. The bigger you are the more you lose. Its not impossible at all. I have lost over 60kg in less then 6 months and mine is all documented with my health team.

          • Cathy Staerkel

            All I think about is food. The shakes are just too blah. This is 3rd day for me and I dont know how I will do this for 4 months. If the taste were better or the nutrition could be in the form of crackers , just something to vary from the shakes, I could see success with the program. Despair…

            • Bre

              Believe me, all I think about is food too, but I’m still going strong on the Optifast diet. I started at 178.5 lbs and I lost 8.5 lbs in the first two weeks with total meal replacements (4 chocolate shakes and 1 soup per day). It’s hard, but is worth it!…My clothes are already getting loose! I eat lots of food in my dreams now lol not going to lie! It’s such a relief that I don’t have to worry about making food for myself anymore or have a pity party after I binge eat something I shouldn’t have. Also, I feel like my taste has changed…initially I put less water in the shakes so the favor would be stronger but now I prefer more water and the taste doesn’t bother me anymore. It’s quick and very convenient…it’s been such a blessing! Hope you continue on with the program 🙂

            • Sharon

              Hi Cathy…The first number of days is the hardest. I found I do better with the soup (chicken..add salt) as it feels like I have had a hot meal. To me, the shakes are just a drink. I found that loosing the sugar addition is what I feel in the first 2 days..ie..a little dizziness and a slight ache down the back of my head (not unlike symptoms when you stop coffee). I do NOT like the aspartame in the product and I think that is what plays havoc with my digestive system..ie..gas! That is terrible! Once I have been on the soups for around a week, I have lost all craving for sweets. I could have chocolate right in front of me and don’t feel the urge to have any and I actually look forward to the soups moreso. It is amazing how the body can be ‘trained’ through habit. Try and hold on just past that first week and you will find is gets so easy..in fact, I not really wanting to eat anything else as the days go by. I wish you well.

            • Connie Pyke

              I lost 33lbs in 11 weeks. I added cinnamon and ginger to the shakes to improve the taste. By day 4 or 5 things will get much easier

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