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Meal Replacement Bars: 8 That May Kick You Out of Ketosis


How do you find the best meal replacement bars when you’re on a ketogenic diet?

Is it OK to replace meals with prepackaged bars that are most likely loaded with carbs and sugar?

What’s the difference between a meal replacement bar and a protein bar, anyway? 

Are meal replacement bars even healthy?

Despite the marketing claims made by many popular “health” bars, these can be anything but healthy when ketosis is your goal. 

They may be low-calorie, low-sugar, soy-free, and non-GMO, but those things alone don’t necessarily make them a healthy snack, much less a nutrient-rich meal replacement.

Meal Replacement Bars vs. Protein Bars

In the United States, the Food and Drug Administration (FDA) doesn’t have a strict definition of what a meal replacement bar must be or contain.

Generally, a meal replacement bar is a prepackaged product intended to be eaten instead of a traditional meal like lunch or dinner.

Hallmarks of the best meal replacement bars include:

  • Portion and calorie control (typically less than 300 calories each)
  • Enough protein to replicate a small meal (between 15 grams to 20 grams)
  • Small amounts of fat to keep you full 
  • Fiber to balance out the carbs 
  • More than 20 vitamins and minerals at the “good” or “excellent” intake levels

Meal replacement bars shouldn’t be your first choice for fuel, but they can help you lose weight in the following ways.

Giving You Easy Portion Control

One study showed dieters underestimate how many calories they eat by almost 40%[*]. Meal replacement bars show you exactly how many calories, fat, and protein you’ll be eating so you don’t have to measure or guess.

Helping You Eat Fewer Calories

A typical meal replacement bar will run under 300 calories, or a lot less than an entire meal will cost you. If a replacement bar keeps you just as full, you may be able to shave off a few hundred calories to get you closer to your scale victory.

Dieters in one study who used meal replacements lost an additional 5.5 pounds in three months and an additional 5.2 pounds at the 12-month mark than participants who didn’t use them[*].

Providing On-The-Go Fuel Between Meals

When you don’t have a keto meal lined up and you’re far from home, a meal replacement bar will keep you from jumping off the wagon and into the drive-thru lane.

Participants in another study added meal replacement bars to their diets and reported less hunger after five hours and greater fullness in that same time compared to those who didn’t add the bars[*].

Still, these bars should only be eaten in moderation and not relied on like a crutch.

Meal replacement bars are no substitute for fresh, whole foods. But they can be incorporated into a healthy diet — as long as you find the right ones. 

How to Find the Best Meal Replacement Bars

Meal replacement bars are supposed to keep you just as a full as a real meal. In order to do that, they need to be fairly comparable to the nutritional weight of your normal breakfast, lunch or dinner. You want a high-quality protein, a decent amount of healthy fat, and loads of fiber. 

Finding a balanced ratio of these three macros is the key to a healthy meal replacement bar.

You need it to trigger your body to stop sending out hunger hormones and start suppressing your appetite after you eat it. That only comes from the right balance of protein, fat, and fiber.

Of course, organic ingredients are a plus and if you need gluten-free or dairy-free, that may narrow your choices even more.

Read on to learn how to spot the good from the bad.

Check the Protein First

There’s no use reading the rest of the label and calculating carbs if you’re not satisfied with the protein count.

A meal replacement bar should contain anywhere from 15 to 25 grams of protein. Anything less than this is more like a protein bar for between-meal snacking. (You can check out the best protein bars if you’re interested.)

This range is roughly the same amount of protein you’d find in:

  • Three eggs (18 grams of protein)
  • 3 oz. T-bone steak (21 grams)
  • 4 oz. chicken breast (25 grams)

If your meal replacement bar fits this, proceed to the carbs (but don’t get your hopes up just yet).

Calculate Carbs and Look at Fiber

Carbs are the biggest sore spot when it comes to narrowing down your choice of bars. Ideally, you want a bar with the fewest net carbs possible.

If the nutritional info doesn’t provide the net carbs, you’ll have to calculate it yourself by subtracting the grams of fiber along with any applicable sugar alcohols (detailed in the next section).

Use the Perfect Keto calculator to determine your macros.

Meal replacement bars, just like real meals, should also be an excellent source of fiber. That means you should try to find ones with at least 5 grams of fiber.

Fiber helps keep you full between meals and reduce those unwanted cravings.

Prebiotic fiber is the best choice since it helps balance the bacteria in your gut microbiome[*].

A majority of the carbs in a meal replacement bar come from the fillers and additives that hold the bar together combined with sugar to make it taste good.

Find the Sugars and Sugar Alcohols 

You may not be familiar with all the ingredient names that hide sugar. They bury the sugar content in what often sounds like natural ingredients. There are over 100 versions of sugar, including:

  • Fruit juice concentrate
  • Glucose
  • Invert sugar
  • Brown sugar
  • Honey
  • Agave
  • Malt syrup
  • Maple syrup
  • Brown rice syrup
  • Raw sugar
  • Molasses
  • Corn syrup
  • Evaporated cane juice
  • Crystal dextrose

Despite these natural-sounding names, sugar is sugar when it comes to being processed in your body. And you know what sugar does — it keeps you out of ketosis. 

A meal replacement bar should have no more than 5 grams of sugar (hopefully less).

Most brands know consumers won’t stand for “health” bars that contain as much sugar as candy bars. So now they’re starting to use artificial sweeteners and sugar alcohols. You can read more about these in the section on suspect ingredients. 

Glance Over the Fat

Pay attention to the fat content not to see if your bar is too fattening or calorie-rich, but to see how much energy it will give you.

When you’re on the keto diet, fats are your main energy source rather than carbs.

Unlike traditional protein bars, a keto-friendly bar won’t rely on carbs to bypass the afternoon crash, so you’ll want to check out the fats after scoping out the protein and carbs.

Stay away from bars using low-quality fats and oils such as:

  • Canola
  • Soybean
  • Peanut
  • Corn
  • Trans fats
  • Partially or fully hydrogenated fats 

And stick to higher quality fats you’d actually eat in a meal, like:

Reach for bars with at least 5 to 10 grams of fat.

Once you research these macros, your final step is reading over the ingredients label for unhealthy additives, artificial sweeteners, and inexpensive fillers.

Red Flags That a “Health” Bar Isn’t Healthy

When you learn what to look for, it will be easier and faster scanning ingredient labels. If you see these sketchy ingredients, put the bar down. There aren’t as many artificial sweeteners and sugar alcohols as there are types of sugar, so it’s easier to spot them:

  • Aspartame
  • Xylitol
  • Mannitol
  • Maltitol
  • Sorbitol
  • Splenda
  • Isomalt
  • Lactitol
  • Sucralose
  • Hydrogenated Starch Hydrolysates
  • Vegetable glycerin

Keep an Eye Out for Vegetable Glycerin 

Made from plant oils like palm, soy, and coconut, glycerin is used as a preservative to keep meal replacement bars moist since it has a texture similar to oil or syrup.

It also has a slightly sweet taste. And since it’s not metabolized like sugar and behaves more like a sugar alcohol, it won’t raise your blood sugar. You’ll see this ingredient often when you go low-carb. But just because it doesn’t raise your blood sugar doesn’t mean it’s good for you. 

Beware of Too Many Sugar Alcohols

Sugar alcohols have been approved by the FDA for use in food, but maltitol, xylitol, and many other sugar alcohols can lead to headaches, stomach cramps, gas, flatulence, diarrhea, and more[*].

Watch for Cheap Fiber and Fillers

Cheap fiber and fillers that act like carbs should be minimized as much as possible. Look for ingredients such as:

  • Chicory root fiber: Also known as inulin, chicory root fiber is a smooth functional fiber with a slightly sweet flavor. It doesn’t get metabolized by your body until it reaches your colon, so while it can keep you regular, if you eat too much and it could create bloating or gas[*]. 
  • Polydextrose: This is a low-cal bulking agent synthesized from glucose and sorbitol — a sweet sugar alcohol metabolized slowly by your body.
  • Isomalto-Oligosaccharide (IMO): New research shows IMOs are actually partially digested, not insoluble fiber as once thought. You’ll need to count these as 50% of the total carbs instead of all fiber[*].
  • Soluble Corn Fiber (SCF): SCF replaced IMO in many popular protein bars. Current research says SCF doesn’t have any impact on your blood sugar or carb count like IMO. Therefore it’s subtracted from the total carbs[*].

Learn to Spot the Fakes

Fake ingredients help preserve low-quality meal replacement bars on the shelf. Watch out for bars containing:

  • Artificial food coloring and dyes
  • Artificial flavors
  • Artificial preservatives
  • Carrageenan
  • BHA and BHT
  • Modified food starch
  • Caramel coloring

With your crash course in the best and worst ingredients wrapped up, take a peek at bars you should definitely avoid.

8 Meal Replacement Bars to Avoid on Keto

When you’re on the keto diet, you learn that close to 95% of the meal replacement bars on the market aren’t going to fit your macros.

They’ll either have too many carbs, too much sugar, or be overflowing in sugar alcohols.

Bad news: meal replacement bars aimed at low-carb dieters can sometimes mess with your blood sugar or digestion more than bars that contain sugar, honey, or agave.

Here are examples of meal replacement bars that are marketed as low-carb, but may kick you out of ketosis.

Meal replacement bars

#1. ThinkThin Chunky Peanut Butter Bar

It’s not cute when you get excited to see a meal replacement bar with zero grams of sugar only to find out it has 21 grams of sugar alcohol from maltitol and glycerin.

At one net carb, you could be tempted to try this, but that many sugar alcohols in one bar can cause some major digestive upset and bloating. Try at your own risk.

Here are the macros from this ThinkThin Chunky Peanut Butter bar[*]:

  • Calories: 240 
  • Fat: 9g 
  • Total carbs: 23g 
  • Fiber: 1g 
  • Sugar: 0g 
  • Sugar alcohol: 21g 
  • Net carbs: 1g
  • Protein: 20g 

#2. Pure Protein Chocolate Deluxe Bar

The base of this Pure Protein bar lists milk protein isolate before whey protein isolate, which means you’re starting off with a less than stellar protein blend for a high 16 grams of net carbs.

Then there’s maltitol and maltitol syrup in everything from the bar itself to the coating. Not to mention the fractionated palm kernel oil, glycerin, and sucralose.

While the 33 grams of protein may entice you, flip to the label where you’ll read all about how the ingredients were partially produced with genetic engineering and how consuming too many sugar alcohols can have a laxative effect.

Check out the nutrition facts for the Pure Protein Chocolate Deluxe flavor[*]:

  • Calories: 280 
  • Fat: 7g 
  • Total carbs: 26g 
  • Fiber: 3g 
  • Sugar: 4g 
  • Sugar alcohol: 7g 
  • Net carbs: 16g
  • Protein: 33g 

#3. Grenade Carb Killa 

What’s in a name? A clever marketing tactic that’s not quite as honest as they claim.

Grenade Carb Killa bars are supposed to be high-protein, low-carb, and keto-friendly, but there’s a major discrepancy in the net carbs they list and their actual effect on your body — thanks to all the different types of sugar alcohols they use.

One bar contains maltitol, xylitol, and sucralose for 11 grams of sugar alcohols that are sure to upset your tummy. And these bars are also made with polydextrose and soybean oil. Yuck.

These are the macros for the Caramel Chaos Carb Killa flavor[*]:

  • Calories: 210 
  • Fat: 8g 
  • Total carbs: 20g 
  • Fiber: 7g 
  • Sugar: 1g 
  • Sugar alcohol: 11g 
  • Net carbs: 2 g
  • Protein: 23 g 

#4. MuscleTech NitroTech Crunch

MuscleTech says their bars are better than their competitors because they use high-biological-value protein sources (which means whey over soy protein).

Yet that doesn’t make up for the use of IMO and low-quality veggie oils like palm, palm kernel, and soybean. Plus, these also pack in maltitol, sugar, and sucralose for sweetness.

One Chocolate Chip Cookie Dough NitroTech Crunch bar comes in at[*]:

  • Calories: 240 
  • Fat: 7 g 
  • Total carbs: 24 g 
  • Fiber: 5 g 
  • Sugar: 5 g 
  • Sugar alcohol: 3 g 
  • Protein: 22 g 

Since these bars use IMO, you can’t trust their net carb count because IMO behaves more like a carb than fiber and can’t be subtracted from the total carbs.

#5. Atkins Meal Bars

Atkins says their low-carb bars are made with simple, quality ingredients and zero refined sugars, artificial flavors, colors, or preservatives.

But that’s not the whole story.

Their meal replacement bars list soy protein, whey protein, and veggie glycerin as the top three ingredients. These bars have just as much glycerin (8g) as fat (9g) and more glycerin than fiber (6g) and doesn’t have much protein.

They also mix in palm kernel oil, polydextrose, and sucralose for good measure.

Here’s what you’ll find on the Chocolate Chip Granola Bar label[*]:

  • Calories: 210 
  • Fat: 9g 
  • Total carbs: 17g 
  • Fiber: 6g 
  • Sugar: 1g 
  • Glycerin: 8g 
  • Net carbs: 3g
  • Protein: 18g 

#6. Clif Builder’s Protein Bars

Though all the ingredients may be organic in the Clif protein bars, it doesn’t mean they’re any good for you.

The first five ingredients for a bar that’s supposed to help you build muscle are mostly sugar: soy protein isolate, beet syrup, organic brown rice syrup, organic cane syrup, and palm kernel oil.

No wonder one bar packs a whopping 21 grams of sugar.

Even though the carbs, aside from sugar, net out and 10 grams of fat and 20 grams of protein are enticing, this Chocolate Peanut Butter Clif Builder may still kick you out of ketosis[*]:

  • Calories: 280 
  • Fat: 10g 
  • Total carbs: 29g 
  • Fiber: 2g 
  • Sugar: 21g 
  • Other carbs: 6g 
  • Net carbs: 21g
  • Protein: 20g 

#7. PowerBar ProteinPlus (Reduced Sugar)

You may do a quick glance at these and think the phrase “reduced sugar” is just what you’re looking for.

Guess again.

Sure, these meal replacement bars may not register more than 3 grams of sugar, thanks to maltitol, but it also means you’re in for 17 grams of gut-wrenching sugar alcohols instead.

One Chocolate Peanut Butter bar clocks in at[*]:

  • Calories: 200 
  • Fat: 7g 
  • Total carbs: 24g 
  • Fiber: 5g 
  • Sugar: 2g 
  • Sugar alcohols: 17g
  • Net carbs: 2g
  • Protein: 20g 

You’ll also see polydextrose, chicory root syrup, glycerin, and sucralose.

PowerBar has come out with a “Clean Whey Protein” line that replaces the soy isolate protein with whey protein isolate. It also removes the artificial sweeteners, flavors, and colors, so you may want to check out those high-protein bars instead[*].

#8. MusclePharm Combat Crunch Bars

Combat Crunch bars don’t taste like the others on this list; they’re baked, so they have the texture of a cookie.

That won’t sound so appealing when you find out they have 15 grams of net carbs.

And that’s not the worst news: Combat Crunch bars still use IMO, so you can’t trust their net carb count to be accurate. In reality, it probably works out to more than 20 grams of net carbs.

Check out the rest of the stats for the popular Chocolate Chip Cookie Dough flavor[*]:

  • Calories: 210 
  • Fat: 7g 
  • Total carbs: 28g 
  • Fiber: 12g 
  • Sugar: 5g 
  • Sugar alcohol: 1g 
  • Net carbs: 15g
  • Protein: 20g 

Though they use more sugar than sugar alcohols, these bars still contain glycerin, maltitol, and sucralose too.

Has all this got you thinking about cutting out the middleman and making your own?

Make Your Own Healthy Meal Replacement Bars

If looking at all those ingredients convinced you that you could make the healthiest keto meal replacement bars out there, here are a few things should be included so you hit all your macros:

Before experimenting with your own concoctions, you may want to try Keto Bars by Perfect Keto.


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