The Slim Fast Diet Plan; Will It Help You To Lose Weight?


How to lose weightWhat is the Slim Fast Diet Plan?

The Slim Fast diet plan is based on meal replacement shakes and bars that are supposed to cut your calorie intake in half. Their shakes and snacks are sold online and in different stores, and you have to provide an additional meal per day.

They claim that by using their weight loss shakes as a meal replacement you will notice results within a week – but are their claims true? Let’s take a deeper look.

How To Lose Weight FastSlim Fast Diet Plan History

Slim Fast was founded in 1977 and was originally a line of diet shake products. Their first shakes were chocolate, vanilla, and strawberry. Later on, during the 90s, they expanded their line of diet products and included meal replacement bars, followed by low-sugar weight loss shakes which were first introduced in the 2000’s.

Today’s diet plan, also known as the 3-2-1 plan, was introduced only 10 years ago and is based on eating six times in the day: three snacks, two shakes, and one full meal.

How To Lose Weight FastHow Does The Slim Fast Diet Plan Work?

The most recent Slim Fast diet plan consists of two meal replacement shakes, one full dinner which you need to provide, and three low-calorie snacks.

By replacing almost all of your regular diet with healthy snacks and weight loss shakes, you significantly reduce your daily calorie intake and as a result, you start to lose weight. All of the shakes are high in protein which has been scientifically proven to decrease appetite.

If you follow the Slim Fast diet plan and their guidelines, on average you will consume around 1,200 calories daily for women and 1,600 calories for men. This reduced calorie intake will allow for a safe weight loss at a rate of 1 to 2 pounds per week.

Even though the diet plan is enough to lose weight due to the low-calorie intake, it’s recommended to pair it with at least half an hour of daily exercise. This will help you maintain a safe rate of weight loss and a healthy lifestyle.

How To Lose Weight FastSlim Fast Diet Plan Menu

The focal point of the whole diet plan is the shakes which come in various flavors and formulas, and are coupled with original protein bars.

Their line of products is very versatile, offering shake and bar lines for every need:

  • Keto – a whole line of Keto-approved shakes with minimal carbs.
  • Diabetes – a new line intended for persons with Diabetes.
  • Advanced Energy – shakes rich in protein for people who need that extra boost of energy.
  • Advance Nutrition – another high-protein line formulated for keeping your appetite at bay.
  • Original – the original line of shakes and bars.

All of the shakes are individually bottled, which is super convenient as you can use them immediately. The best part about them is the flavors, which are plenty and difficult to get bored of. Some of the most delicious flavors include: Cappuccino Delight, French Vanilla, Caramel Latte, Mocha Cappuccino, Rich Chocolate, and Strawberries & Cream.

As for the dinner, their recommendation is a full healthy meal to end the day. The meal should include half of your plate with vegetables, a quarter with lean protein (tofu, fish, chicken), and another quarter with starch (rice, whole wheat pasta, potatoes).

The nutritional value of the shakes varies but is typically within the range of:

  • Calories: 180-200
  • Fat: 3-5 grams
  • Carbohydrates: 1-20 grams
  • Fiber: 5 grams
  • Protein: 10-20 grams

When comparing the nutritional value and the ingredients in the Slim Fast shakes to a regular homemade shake however, there is a big difference. One of the main ingredients in almost all of the shakes is sugar. In addition, the shakes also contain artificial sweeteners (Acesulfame Potassium, Sucralose), genetically modified oils, artificial flavors, and milk protein concentrates, which is processed milk without any minerals.

Additionally, some of the shakes even contain a high dose of added sodium, which can lead to high blood pressure when taken too much. The Cappuccino Delight, for instance, has 15% of your recommended daily sodium intake.

How To Lose Weight FastThe Pros and Cons of the Slim Fast Diet Plan


  • Convenience – all the shakes are premade and individually bottled, meaning you won’t have to do any preparation or planning – just open the bottle and you’re good to go.
  • Easy to follow – the 3-2-1 plan is easy to follow and doesn’t require any additional cooking or prepping.
  • Portion control – by following their meal plan, you effectively reduce your calorie intake and consume just enough to keep you going through the day.


  • Processed food – all of the shakes and snacks contain artificial or modified ingredients, which are stripped of any nutritional value. A healthy diet requires organic products without any processed food or added sweeteners.
  • No support – the lack of support and community is what prevents the Slim Fast diet plan from becoming one of the best weight loss programs. No weight loss journey is complete without having someone to talk to and share experiences.
  • Does not teach portion control – even though all the shakes are low in calories, you’ll find it difficult to maintain the same calorie intake when you finally reach your desired weight.

How To Lose Weight FastThe Cost Of The Slim Fast Diet Plan

The shakes needed for the Slim Fast diet plan are sold in grocery stores and online. Their price is between $1.5-4 per serving. When taken twice a day, the shakes alone account for around $120 per month, which is expensive when you consider the blend of artificial ingredients you’ll consume.

How To Lose Weight FastDoes Slim Fast Help You Lose Weight?

The short answer is yes – the Slim Fast diet plan will help you lose weight. Many people even consider it the best weight loss program as it is convenient and versatile – consumer reviews suggest that they lost around 6 pounds per month.

Still, it’s not a long term solution as most of the food you will be consuming is processed and has low-quality ingredients. If you’re looking for a healthier way on how to lose weight, you might be better off with another plan that teaches portion control and includes fresh and quality products.

How To Lose Weight FastConclusion; The Slim Fast Diet Plan Rating

The Slim Fast diet plan is an effective way of losing weight as the meal replacement shakes are delicious and have a low-calorie count. Still, the overall quality of the products is poor and is not a healthy option for replacing your meals in the long run.

We rate this diet 3 out of 5 stars.