Slimfast vs Perfect Keto Bars

Meal replacement bars are a portable, convenient way to stay on track with your diet. 

Whether you’re traveling, busy, or just want a break from meal prep, there are countless reasons you might reach for a bar.

However, not all meal replacement supplements are created equal. Flavor, ingredient quality, and nutritional value can vary drastically from one brand to another.

And by the same token, there are smart and not-so-smart ways to fit bars into your routine. Munching on your favorite meal replacement bar daily is okay, but using it to replace healthy whole foods altogether isn’t the wisest choice.

In this article, we’ll explore the differences between Slimfast Bars and Perfect Keto Bars, pros and cons of each, and which one comes out ahead for your low-carb, high-fat lifestyle. 

We’ll also examine how to use keto bars as a supplement to enhance your healthy lifestyle–without becoming overly reliant on them or using them as a crutch.

What Is Slimfast?

Slimfast is an American company headquartered in Florida that sells weight loss products. The company is best known for its shakes, but they also offer snacks, bars, pre-packaged meals, and dietary supplements.

Originally founded in 1977, Slimfast first offered diet shake mixes in chocolate, strawberry, and vanilla. People drank the shakes in place of a solid food breakfast or lunch. Then, for dinner, they would have a 500-calorie meal consisting of vegetables, lean protein, and whole grains

Within the past few years, Slimfast has gone all-in on the keto trend. While they still offer their “Original” shakes, most of their recent products are targeted at people on the keto diet (or people who have heard of the keto diet and are willing to try Slimfast’s keto product line).

According to Slimfast, the combination of protein and fats in their products decreases hunger, resulting in an easy 1-2 pounds of weight loss per week if you follow their plans.

However, as with any diet plan that relies on processed substitutes for whole foods, the nutritional quality of those products is an important consideration.

Next, we’ll take a closer look at the nutrition facts and ingredients found in various Slimfast bars.

Slimfast Bars Nutrition

According to its website, Slimfast now sells two types of weight loss bars: Keto and Diabetic Weight Loss.

These categories represent a major departure from the previous line of weight loss bars, which were much higher in carbs. Since the older Slimfast bars are now discontinued, we’re only covering what is available at present.

Below, you’ll find nutrition info for Slimfast Keto Meal Replacement Bars as well as Diabetic Weight Loss Bars.

Slimfast Keto Whipped Peanut Butter Chocolate Meal Bars

• Serving Size: 1 Bar (42 grams)
• Calories: 190 kcal
• Total Fat: 14g
• Saturated Fat: 7g
• Total Carbs: 15g
• Dietary Fiber: 9g
• Sugar: 3g (3g added sugar)
• Sugar Alcohols: 2g (from erythritol)
• Protein: 7g
• Vitamin D 5mcg (25% DV) 
• Iron 4mg (20% DV) 
• Vitamin A 375mg (40% DV) 
• Vitamin E 12mg (80% DV) 
• Thiamin 0.5mg (40% DV) 
• Niacin 9mg (60% DV) 
• Folate 167mg DFE (40% DV) 
• Biotin 135 mcg (450% DV) 
• Phosphorus 150mg (10% DV) 
• Magnesium 98mg (25% DV) 
• Selenium 7mcg (15% DV) 
• Manganese 1mg (45% DV) 
• Molybdenum 23mg (50% DV) 
• Calcium 64mg (4% DV) 
• Potassium 82mg (2% DV) 
• Vitamin C 27mg (30% DV) 
• Vitamin K 20mcg (15% DV) 
• Riboflavin 0.5mg (40% DV) 
• Vitamin B6 0.7mg (40% DV) 
• Vitamin B12 2.7mcg (110% DV) 
• Pantothenic acid 5mg (100% DV) 
• Iodine 45mcg (30% DV) 
• Zinc 5mg (45% DV) 
• Copper 0.3mg (35% DV) 
• Chromium 48mcg (140% DV)

All the Keto Meal Bars have similar nutrition facts, including the 25(!) added vitamins and minerals, so we’ll skip listing the other flavors.

Slimfast Diabetic Weight Loss Peanut Butter Chocolate Meal Bars 

• Serving Size 1 Bar (42 grams)
• Calories: 190 kcal
• Total Fat: 14g
• Saturated Fat: 7g
• Total Carbs: 15g
• Dietary Fiber: 9g
• Sugar: 3g (3g added sugar)
• Sugar Alcohols: 2g (from erythritol)
• Protein: 7g
• Vitamin D 5mcg (25% DV) 
• Iron 4mg (20% DV) 
• Vitamin A 375mg (40% DV) 
• Vitamin E 12mg (80% DV) 
• Thiamin 0.5mg (40% DV) 
• Niacin 9mg (60% DV) 
• Folate 167mg DFE (40% DV) 
• Biotin 135 mcg (450% DV) 
• Phosphorus 150mg (10% DV) 
• Magnesium 98mg (25% DV) 
• Selenium 7mcg (15% DV) 
• Manganese 1mg (45% DV) 
• Molybdenum 23mg (50% DV) 
• Calcium 64mg (4% DV) 
• Potassium 82mg (2% DV) 
• Vitamin C 27mg (30% DV) 
• Vitamin K 20mcg (15% DV) 
• Riboflavin 0.5mg (40% DV) 
• Vitamin B6 0.7mg (40% DV) 
• Vitamin B12 2.7mcg (110% DV) 
• Pantothenic acid 5mg (100% DV) 
• Iodine 45mcg (30% DV) 
• Zinc 5mg (45% DV) 
• Copper 0.3mg (35% DV) 
• Chromium 48mcg (140% DV)

You may have noticed the Keto Bars and Diabetic Weight Loss Bars have identical nutrition facts. 

It’s odd, but true–even though they’re for different purposes. (Slimfast Keto Bars are designed to help “kickstart ketosis,” while the Diabetic Weight Loss Bars are for “blood sugar management” and “supporting a healthy weight” in individuals with diabetes.)

Slimfast Bars Ingredients

Slimfast Keto Whipped Peanut Butter Chocolate Meal Bars: MCT & Butter Blend (MCT Oil Blend (Palm, Coconut), Peanut Butter, Cocoa Butter, Almond Butter), Inulin, Soluble Corn Fiber, Protein Blend (Whey Protein Isolate, Milk Protein Isolate), Unsweetened Chocolate, Tapioca Syrup, Erythritol, Natural Flavor, Peanut Flour, Whey Protein Crisps [Whey Protein Isolate And/Or Whey Protein Concentrate, Tapioca Starch or Corn Starch, Cocoa (Processed With Alkali), May Contain Calcium Carbonate and Sunflower Lecithin], Glycerin, Sea Salt, Sunflower Lecithin, Stevia Extract, Natural Vanilla Extract, Mixed Tocopherols

Slimfast Diabetic Weight Loss Peanut Butter Chocolate Meal Bars: MCT & Butter Blend (MCT Oil Blend (Palm, Coconut), Peanut Butter, Cocoa Butter, Almond Butter), Inulin, Soluble Corn Fiber, Protein Blend (Whey Protein Isolate, Milk Protein Isolate), Unsweetened Chocolate, Tapioca Syrup, Erythritol, Natural Flavor, Peanut Flour, Whey Protein Crisps [Whey Protein Isolate And/Or Whey Protein Concentrate, Tapioca Starch or Corn Starch, Cocoa (Processed With Alkali), May Contain Calcium Carbonate and Sunflower Lecithin], Glycerin, Sea Salt, Sunflower Lecithin, Stevia Extract, Natural Vanilla Extract, Mixed Tocopherols

(Note: these ingredients lists don’t include the 25 added vitamins and minerals in each bar, which are listed in the previous section.)

Now, if the Nutrition Facts didn’t clue you in already, the ingredients lists should confirm that Slimfast Keto Bars are the same product as Slimfast Diabetic Weight Loss Bars but with different labeling.

How Do Slimfast Bars Taste?

Slimfast Keto Meal Bars come in 5 flavors:

• Whipped Triple Chocolate
• Chocolate Chip Cookie Dough
• Salted Caramel Macadamia Nut
• Nutty Caramel and Nougat
• Whipped Peanut Butter Chocolate

And the Diabetic Weight Loss Bars come in 3 flavors:

• Double Chocolate Cookie Dough
• Peanut Butter Chocolate
• Creamy Chocolate Mousse

On the positive side, people say Slimfast bars are “good for satisfying chocolate cravings, and ”a nice sweet fix.”

But on the negative side, criticisms from real people include “too sweet,” “strong aftertaste,” “very hard, nearly inedible crunchy bits,” and “could break a tooth.”

In the end, taste and flavor are fairly subjective. You can’t please everyone. But it’s safe to say that you may want to avoid Slimfast bars if you don’t like your bars ultra-sweet and mega-crunchy.

What Are Perfect Keto Bars?

Perfect Keto is an Austin, Texas company founded by Dr. Anthony Gustin in 2016–shortly before the current keto craze took off.

All of Perfect Keto’s products use clean ingredients for better health. That means the best possible keto-friendly real foods and other science-backed, active ingredients to get the job done, gluten free and without any fillers or substitutes. Also absent are added sugars, artificial ingredients, grains, soy, and corn. 

As the name suggests, Dr. Gustin designed Perfect Keto Bars to be the optimal low-carb meal replacement option on the ketogenic diet.

Perfect Keto Bars Nutrition

Perfect Keto Bars work for a range of purposes: as a quick breakfast option, to kick afternoon carb cravings, for clean energy before a workout, or to satisfy the occasional sweet tooth with zero guilt.

All of the bars have similar nutritional values and work equally well, regardless of your goals or needs. In fact, you don’t even have to be on the keto diet to enjoy them.

Birthday Cake Keto Bars 

• Serving Size 1 Bar (45 grams) 
• Calories: 230 kcal 
• Total Fat: 17g 
• Saturated Fat: 4g 
• Total Carbs: 11g 
• Dietary Fiber: 8g 
• Total Sugars: 1g (0g added sugars) 
• Protein: 13g 
• Calcium: 70mg (6% DV) 
• Iron: 0.7mg (4% DV) 
• Potassium: 150mg (4% DV)

Cinnamon Roll Keto Bars

• Serving Size 1 Bar (45 grams) 
• Calories: 220 kcal 
• Total Fat: 17g 
• Saturated Fat: 4g 
• Total Carbs: 12g 
• Dietary Fiber: 9g 
• Total Sugars: 1g (0g added sugars) 
• Protein: 11g 
• Calcium: 100mg (8% DV) 
• Iron: 1.2mg (6% DV) 
• Potassium: 10mg (% DV)

Chocolate Chip Cookie Dough Keto Bars

• Serving Size 1 Bar (45 grams) 
• Calories: 230 kcal 
• Total Fat: 18g 
• Saturated Fat: 6g 
• Total Carbs: 12g 
• Dietary Fiber: 9g 
• Total Sugars: 1g (0g added sugars) 
• Protein: 11g 
• Calcium: 80mg (6% DV) 
• Iron: 1.1mg (6% DV) 
• Potassium: 200mg (4% DV)

Salted Caramel Keto Bars

• Serving Size 1 Bar (45 grams) 
• Calories: 240 kcal 
• Total Fat: 18g 
• Saturated Fat: 7g 
• Total Carbs: 11g 
• Dietary Fiber: 9g 
• Total Sugars: 1g (0g added sugars) 
• Protein: 11g 
• Calcium: 40mg (4% DV) 
• Iron: 0.8mg (6% DV) 
• Potassium: 130mg (2% DV)

Almond Butter Brownie Keto Bars Salted Caramel Keto Bars

• Serving Size 1 Bar (45 grams) 
• Calories: 240 kcal 
• Total Fat: 19g 
• Saturated Fat: 7g 
• Total Carbs: 11g 
• Dietary Fiber: 9g 
• Total Sugars: 1g (0g added sugars) 
• Protein: 11g 
• Calcium: 50mg (4% DV) 
• Iron: 1.2mg (6% DV) 
• Potassium: 180mg (4% DV)

Lemon Poppyseed Keto Bars 

• Serving Size 1 Bar (45 grams) 
• Calories: 240 kcal 
• Total Fat: 18g 
• Saturated Fat: 6g 
• Total Carbs: 10g 
• Dietary Fiber: 9g 
• Total Sugars: 1g (0g added sugars) 
• Protein: 11g 
• Calcium: 70mg (6% DV) 
• Iron: 1mg (6% DV) 
• Potassium: 140mg (2% DV)

Pumpkin Spice Keto Bars:

• Calories: 210
• Fat: 16g
• Protein: 12g
• Carbs:
  • Net carbs:  3g
  • Calculation: 12g of carbs – 3g fiber – 0g sugar alcohol – 6g of allulose = 3g

Peanut Butter Chocolate Chip Bars:

• Calories: 240
• Fat: 18g
• Protein 13g
• Carbs: 10g
  • Net carbs:  3g
  • Calculation: 10g of carbs – 2g of fiber – 0g of sugar alcohols – 5g of allulose = 3g

Perfect Keto Bars Ingredients

Perfect Keto Birthday Cake Bars: Almond Butter, Soluble Tapioca Fiber, Grass Fed Bovine Collagen, Cacao Butter, Sunflower, Lecithin, MCT Oil (Derived from coconut), Edible Glitter (Gum Arabic, Spirulina Extract, Red Cabbage Extract, Turmeric Extract, Radish Extract), MCT Oil Powder (MCT Oil, Acacia Powder), Natural Flavors, Sea Salt, Organic Vanilla Extract, Monk Fruit Extract, Stevia

Perfect Keto Cinnamon Roll Bars: Almond Butter, Soluble Tapioca Fiber, Grass Fed Bovine Collagen, Cacao Butter, Organic Cashews, Coconut Oil, Sunflower Lecithin, Cinnamon, Natural Flavors, MCT Oil Powder (MCT Oil, Acacia Fiber), Sea Salt, Stevia

Perfect Keto Chocolate Chip Cookie Dough Bars: Almond Butter, Soluble Tapioca Fiber, Grass Fed Bovine Collagen, 100% Chocolate Chips From Cacao Nibs, Cacao Butter, Sunflower Lecithin, Coconut Oil, Organic Vanilla Extract, Natural Flavors, MCT Oil Powder (MCT Oil, Acacia Fiber), Sea Salt, Monk Fruit Extract, Stevia

Perfect Keto Salted Caramel Bars: Almond Butter, Soluble Tapioca Fiber, Grass Fed Bovine Collagen, Cacao Butter, Sunflower Lecithin, Natural Flavors, MCT Oil Powder (MCT Oil, Acacia Fiber), Sea Salt, Stevia

Perfect Keto Almond Butter Brownie Bars: Almond Butter, Soluble Tapioca Fiber, Cacao Butter, Grass Fed Bovine Collagen, Organic Cocoa, Almonds, Sunflower Lecithin, Coconut Oil, Sea Salt, Natural Flavors, Stevia

Perfect Keto Lemon Poppyseed Bars: Almond Butter, Soluble Tapioca Fiber, Grass Fed Bovine Collagen, Cacao Butter, Poppy Seeds, Sunflower Lecithin, Almonds, MCT Oil Powder (MCT Oil, Acacia Fiber), Natural Flavors, Sea Salt, Stevia, Organic Lemon Oil

Perfect Keto Peanut Butter Chocolate Chip Bars: Peanut Butter, Grass Fed Bovine Collagen, Allulose, 100% Cacao Chocolate Chips, Peanuts, Cocoa Butter, MCT Oil Powder (MCT Oil from Coconut, Acacia Gum), Sunflower Lecithin, Coconut Oil, Natural Flavors, Sea Salt, Stevia, Monk Fruit Extract.

Perfect Keto Pumpkin Spice Keto Bars: Almond butter, allulose, grass fed bovine collagen, cocoa butter, organic cashews, sunflower lecithin, coconut oil, pumpkin pie spice, pumpkin powder, organic vanilla extract, mct oil powder, cinnamon, sea salt, ginger, natural flavors, stevia, monk fruit extract.

How Do Perfect Keto Bars Taste?

Here’s positive real-world feedback from people who have enjoyed Perfect Keto Bars:

• “It isn’t too sweet (sweetened with stevia) but has a great chocolate flavor.”
• “The TEXTURE is soft and not hard like other bars I’ve tried.”
• “Doesn’t taste like a typical ‘protein bar’ and goes great with coffee.”
• “I usually spend 10-15 mins nibbling on it. I like this difference from other bars; I enjoy my breakfast more.”

And on the less positive side:

• “It tastes good, but don’t expect it to be your typical HIGH carb granola, snickers, or energy bar.”
• “Not as tasty as some other bars out on the market.”
• “The salted caramel is a little too sweet for my liking. I also have had the chocolate chip cookie dough and like that flavor better. I’ll still finish this box but won’t buy this flavor again.”

Of course, taste buds aren’t all the same, and preference inevitably enters into the equation. But at least you can choose from 6 unique flavors.

Are Slimfast Bars Keto-Friendly?

Will Slimfast Bars kick you out of ketosis all by themselves?

Probably not. According to test reports from people who follow the keto diet, Slimfast Keto Bars (and the literally identical Diabetic Weight Loss Bars) do not have enough net carbs to end ketosis as measured by keto test strips and blood glucometers.

By that definition, they are keto-friendly.

Read Soluble Tapioca Fiber: What Is It? (And Is It Keto-Friendly?) to learn more about IMOs and why they can be a problem on the keto diet.

The other problem is that Slimfast Bars have a number of unnecessary and potentially unhealthy ingredients.

Specifically, we’re talking about the 25 added vitamins and minerals. Throwing in the “kitchen sink” of processed micronutrients is a bit of a red flag in the nutrition world; if you start with healthy ingredients, you don’t need to fortify your product with artificial ones.

This tactic is commonly associated with mass-produced white bread and refined breakfast cereals, not high-quality keto staples.

But more importantly, recent research has suggested these types of supplemental nutrients aren’t helpful, and may even be harmful[*]. 

According to the authors of a 2014 review, “Antioxidant supplements do not possess preventive effects and may be harmful with unwanted consequences to our health, especially in well-nourished populations”[*].

Slimfast vs. Perfect Keto Bars

Here’s how Slimfast Keto Bars and Diabetic Weight Loss Bars stack up against Perfect Keto Bars:

• Macros and Nutrition: Slimfast Bars have fewer calories, but keto isn’t solely about restricting calories. Perfect Keto Bars have more protein and healthy fats, giving them the edge as far as macronutrients.
• Ketosis: Both products potentially allow you to stay in ketosis, but you should probably count the IMOs in Slimfast Bars as net carbs. As always, test and verify for yourself, but there is a non-zero risk of exiting ketosis with Slimfast products.
• Ingredients: Perfect Keto Bars contain grass fed collagen, a special type of protein with unique benefits. Further, they’re sweetened with stevia and monk fruit and contain no sugar alcohols, making them a cleaner source of energy. 
• Flavor: Your favorite flavor comes down to personal preference, but you’ve got more flavors to choose from with Perfect Keto. 

	Calories	Net Carbs	Healthy Fats	Protein	Added Sugar?	IMOs?	Corn or Grains?	Contains Dairy?	Sugar Alcohols or Artificial Sweeteners?
Perfect Keto Bars	220-240 kcal	1-3g	17-19g	11-13g	No	No	No	No	No
Slimfast Bars	180-190 kcal	12-15g*	12-14g	7-9g	Yes	Yes	Yes	Yes	Yes

*Counting isomaltooligosaccharides (IMOs) as net carbs, which appear to be incorrectly counted as “Fiber” on the Slimfast Bars label.

The Takeaway

You could call us biased, but we think Perfect Keto Bars are a superior choice, and we’ve shared all the reasons why. You can also find the Keto Bars in our Perfect Keto Starter Kit.

If you prefer real, simple ingredients, fewer net carbs, more healthy fats and protein, and more flavor options, Perfect Keto is the way to go.

The truth is that Slimfast recently underwent a rebrand from high carb diet products to low-carb, ketogenic nutrition products. (They even offer fat bombs–can you imagine the old Slimfast of the 1980s selling fat bombs?)

Clearly, the keto diet works, whereas studies showed mixed results from the old Slimfast plan and its accompanying high-carb Slimfast bars[*][*].

Some people might call flip-flopping bad optics, but we can’t fault Slimfast for moving towards a more effective and research-backed keto approach.

The biggest legitimate criticism of Slimfast still applies, though: they encourage substituting their products in place of real food for 2 out of 3 meals each day. While this strategy is probably effective from a sales perspective, the truth is that healthy diets require eating real, whole foods the majority of the time.

Some people may still opt for Slimfast Keto products due to cost, availability, or flavor. Unfortunately, many of their ingredients fit better into a dirty keto diet than a clean keto diet, and it’s no secret that we recommend the clean version.

Ultimately, bars and other supplements are just one part of your keto equation. Regardless of which keto bar you choose, you’ll still need to educate yourself about keto and follow through to get good results.