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Slim Fast 321

Slim Fast 321

Slim down on this easy and flexible weight loss plan.

Top Rated Diet Shakes of 2016
BACKGROUND Start the Diet Now Advertisement

Slim Fast 321 is a three-step weight loss plan that offers both structure and flexibility.

The numbers three, two and one correspond to how many meals and snacks you will be eating throughout the day.

You can follow the Slim Fast 321 plan by registering for the diet on the Slim Fast website. Registration is free.

Here is how the plan works:

  • You have three, 100-calorie snacks, which can be either a Slim Fast 100-calorie bar or 100 calories worth of fruit, vegetables or nuts.

  • Next, you have two Slim Fast shakes or meal bars, each of which are worth about 300 calories. Finally, you have one 500-calorie meal per day.

  • The Slim Fast Slim Fast website provides you with a list of meal ideas, as well as a chance for you to chart your own progress and connect with others who are also trying to lose weight.

Slim Fast products can be found in grocery stores all over the country as well as ordered online.

Do You Know the Best Diet Shakes of 2016?

  • Encourages portion control
  • Created by a well-recognized name in the meal replacement diet industry
  • Eating frequently throughout the day can curb feelings of diet deprivation
  • Website offers a host of supportive tools to help you reach weight loss goal
  • Encourages eating fruits, vegetables and lean proteins
  • Named #3 in the Best Commercial Diets by US News, 2011
  • Meal replacement diets have not demonstrated long-term weight loss success
  • Eating only Slim Fast products can lead to cravings for other foods
  • Plan lacks variety

The Slim Fast 321 Plan is a straightforward diet that encourages eating six portioned meals or snacks throughout the day.

Slim Fast is widely recognized for its line of meal replacement shakes and bars and this diet recommends eating two or more of these products every day.

Slim Fast shakes and bars are high in protein and fiber.

Here is a typical day on the Slim Fast 321 Plan:

  • Breakfast: One Slim Fast 321 Shake or a Slim Fast Bar
  • Snack: One-half of a banana, one pear or one Slim Fast 100-calorie Snack Bar
  • Lunch: One Slim Fast 321 Shake or a Slim Fast Bar
  • Snack: One medium apple, one cup of strawberries or one Slim Fast 100-calorie Snack Bar
  • Dinner: Grilled halibut with veggies, fish tacos, Asian beef salad
  • Snack: Two medium apricots or one Slim Fast 100-calorie Snack Bar

A two-week sample menu plan is included on the website as are portion guides for your one daily meal and sample meal ideas.


Exercise is an integral part of the Slim Fast 321 Plan. Regular exercise not just improves weight loss outcomes but it also contributes to overall wellness.

On the plan, you are encouraged to exercise on most days of the week, doing a combination of cardiovascular and strength-training exercises.

You can track your exercise progress on your online progress calendar.


The Slim Fast 321 plan is not as easy as 1-2-3, but it is a straightforward diet that requires you adhere to the frequenting noshing of Slim Fast products and the characteristic "sensible meal."

While this plan gets high remarks for its structure and encouragement of portion control, it falls short on variety and its reliance on fruit. Therefore, for those who are diabetic, you should talk to your doctor before starting this plan.

Common Misspellings

slimfast 321, slim fast 123, slim-fast 321, 321 slimfast, 321 slim fast, slim fast three two one, slim fats 321

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User Feedback

(Page 2 of 2, 39 total comments)

Julian Ferretti


I am on my third day of the 321 plan. I drink only strawberries and cream for breakfast and lunch thenwhatever i can make thats >500 caloties when i get home. i only eat one snack usually between lunch and dinner since i have almost an 8 hour wait time in between.After dinner i do a 30 minute uphill bike ride. So far i have lost 9 pounds in my first two days and possible more when i weigh myself tonight. I like the program so far. Shakes tastes good, not minerally like other brands and snack choices are easy not that everyone makes 100cal snacks.

posted Sep 14th, 2011 1:04 pm



Today is day one for my slim fast 321 plan and I have a tip for those feeling hungry and to boost weight loss results. Eat high fibre snacks! There is no fibre in slim fast and it's a key in weight loss or maintaining. It makes you feel full and you retain less water.

posted Aug 4th, 2011 12:49 pm



Tomorrow 8/4/2011 will be my first day I have all my meals and shakes taped with day one, two etc so I don't get spontanious and reach for a QUICK fix!! I'm very nervious but I'm so motivated that I'm gonna do this.. I have already been walking a 1.5 miles perday on treadmil, I've made a schedule for adding Julian Micheals video in with weight training 3 days a week. I've plan it out for the first time in my life and I going forward and not looking back...

posted Aug 2nd, 2011 4:29 pm


I started on May 11, 2011 and have lost 27 pounds so far. I am now near my weight range again. Am 69 years old and have used weight watchers anytime I was struggling with weight, but now at 69 I couldn't lose until I tried the 3 2 1 plan. I have arthritis in my knees so have stopped walking my daily 3 miles and that's when I turned to slimfast. I now am having much less problem with my knees. I take an aquasize class for 1 hour four times a week, swim 11 laps (worked up from 1 lap!!) 4 times a week, and on the other two days I walk for just a half hour each of the two days. I love the diet--I love chocolate so never get tired of the chocolate royal, I never have the slimfast snacks --instead I eat a salad, or egg whites and tomatoes, or a yogurt, or grapefruit or other fruit--anything reasonable. I decide my meal ahead of time as to when I will have it. If hubby wants to go out to eat that evening then that will be my meal; if I make homemade bread and hunger for it then I have it for my breakfast--5 slices!!!! Most of the time I have my "meal" at lunch time as it fits best for me, but like I said I've had it at breakfast and at dinner from time to time too.I lose every week and average 2 lbs a week. I lost 5 the very first week but mostly it's 2 lbs or even as low as 1 lb once in awhile but I always lose. I love it and could do it forever!!!!!!!!!!!

posted Jul 22nd, 2011 9:15 pm


Today is day 1, so far so good. I'm planning on eating my 500 cal. meal at the lunch time. This way I won't get 2 shake meals in a row, and I can have more time to burn it off.

posted Jun 20th, 2011 2:50 pm



I just started the Slim Fast plan 2 days ago and so far it's been great. Day 1 is always the hardest but day 2 was much better. I've been drinking a ton of water and instead of eating my 500 calorie meal as my last meal of the day I eat it as the second meal that way it has more time to burn off through out my day. So far I've lost 4.5 pounds in 2 days so I'm very satisfied with my results.

posted Jun 20th, 2011 10:05 am


You definitely have to exercise with it but its been one week, and i have lost 1 inch around my waist and 5 lbs. (keep in mind i never exercised and ate whatever i wanted, and i smoked.) I no longer smoke, I eat healthy, exercise for 30 min everyday, and i swear by slim fast 321 plan!

posted May 20th, 2011 12:13 pm

michele Phillips

I love it ....

posted Apr 15th, 2011 1:17 pm



Although working at Subway might help a bit, I've actually lost about 25 pounds since I started this diet last month (Feb. 23rd, 2011)

I just have to say: it's wonderful.
It's easy to stay on, and you can find many meal choices under 500 calories.

Thanks, Slim Fast
You rock!
*thumbs up*

posted Mar 18th, 2011 6:07 pm


i like the diet plan and i am not hungry at all only the first day thank you slim fast you are the one for me

posted Feb 24th, 2011 11:53 am


I have been on this plan for a month and i have been starving! it is so hard to not cheat. i am not impressed at all

posted Feb 21st, 2011 9:37 pm


I went on Slimfast years ago after I gained 30lbs when I quit smoking. I lost 30lbs in 3 months. I found the diet convenient (you just throw your lunch into your bag and go). It can get a bit boring, but by the time that happens your pants are loose and that keeps you going. I'm older now and don't expect the same results I had then (I've got thyroid problems now), but I'm game for trying. WW didn't help me at all and I really stuck to it. Wish me luck!

posted Feb 15th, 2011 11:13 am



i was starving trough the whole diet didnt quite work out for me

posted Jan 3rd, 2011 6:00 pm

Anna Potts


I started the 3-2-1 plan on Friday.. I weighed in Friday morning & weighed 189.8 & this morning (Sunday) I weighed in at 185.4.. That's 4.4 lbs in 2 days!!! & I havent even worked out.. I'm gonna start working out & hopefully lose even more.. This plan works GREAT! I replace breakfast & lunch with a shake .. & for my snacks I eat the 100 calorie packs (so I can get in my sugar & salt cravings without messing up my progress) & dinner I have just been making whatever stays right around 500 calories.. I have also been drinking a LOT of water

posted Dec 12th, 2010 3:21 pm



I started this diet 7 days ago and have lost 6 pounds. No exercise. Lots of water. I am alot over weight so that may be why I lost so much in a week.

posted Sep 16th, 2010 12:07 pm


I have tried for ten years to lose even a couple of pounds with no success. Really. I didn't want to join a dieting group plan and I didn't want to keep track of points and I didn't want to buy meals. I bought two 6 packs of Slim Fast and in two weeks I lost 3 pounds. All I have done is eat a regular breakfast and lunch, and have a Slim Fast for dinner. Period. I am not hungry. Now, it has been a month and I've lost 7 pounds. HOORAY!

posted Aug 20th, 2010 9:01 pm


I am adding the slim fast into my diet because my wife didn't want to finish her's. But I do get up early and run for 2 miles or 30 mins before work everyday. Plus I'm putting the Insanity workout along with it. My goal is a 35 lbs loss. I drink the slim drinks , and or bars along with three other small meals no bigger than my fist. I'll keep an update weekly. Everyone keep it up!!

posted Jul 13th, 2010 6:36 pm



I'm due for my first weigh in on Wednesday, up to now i've found the plan easy to follow. At the moment Boot's have slimfast powder on special at half price so I've stocked up. I feel much better in myself, more energy and get up and go.

posted Jun 28th, 2010 6:12 am



I 'm on day 1 and I like it! I'm not naive about the fact that it isn't a long term plan AT ALL! However, I think it's a great plan for ladies who wanna drop some holiday pounds, and ease into a more long term eating plan. I'm using the website and it's really awesome that they give you options that aren't all Slim Fast products! I have my ending date as the middle of July so I think it's a good plan for a month or two but nothing more!

posted Jun 8th, 2010 10:57 am


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