Thursday, 23 May 2024

Protein Bars

Optimum Nutrition Opti-Bar Protein Bar Review

Last updated on

This site may contain links to affiliate websites, and we receive an affiliate commission for any purchases made by you on the affiliate website using such links. Read Our Disclosures

Each 60 gram Optimum Nutrition Opti-Bar provides your body with 20 g of protein, 20 g of carbohydrates, 9 g of fat, and 250 calories. They’re also a good source of dietary fiber, with 10 g per bar (40% of RDA).

But unlike most protein powders, there’s no creatine, L-glutamine, or BCAAs. So can they still be an effective source of pre-workout and post-workout nutrition?

In this review we’ll compare O.N. Opti-Bars to two other top-rated protein bars; MusclePharm Combat Crunch, and MuscleTech Mission1.

Comparisons include the levels of protein, carbs, and fats, as well as the cost per serving, flavors, customer feedback, and total calories.

This is to guarantee you only buy the best protein bar for your current diet and fitness goal. Whether that’s weight loss, lean muscle gain, bulking, or simply to boost your daily protein intake.

Optimum Nutrition Opti-Bar Ingredients

Optimum Nutrition Opti-Bar Protein Bar Ingredients

Each Opti-Bar delivers 20 g of protein, using a blend of milk protein isolate and whey protein isolate. The fact that one hundred percent of protein comes from isolate sources means you enjoy a much more purer protein.

One of its key selling points is the high level of fiber in relation to sugar content. With 10 grams of dietary fiber per bar, and just a few grams of sugar, it’s a much healthier option compared to the original protein bars from Promax (1 g of fiber and 30 g of sugar).

Calorie content is moderate, kept lower thanks to the low carb recipe. Fat content (9 g) is a little higher than some protein bars we’ve reviewed (Pure Protein Bar: 5g, thinkThins: 8 g), but this is somewhat dependent on the flavor. Cookies N Creme is 9 g of fat per bar, while Chocolate Brownie and Choc Chip Cookie Dough flavors deliver just 7 g.

The overall taste and texture of the bars is excellent, whichever flavor you choose. Optimum Nutrition have clearly called on their experience with creating industry-leading whey protein powders before first marketing these protein bars in 2016.

What’s in Opti-Bar Protein Bars?

Optimum Nutrition Opti-Bar Ingredients Label (Cookies N Creme)
Ingredient Amount per Serving % Daily Value
Calories 250
Total Fat 9 g 14%
Saturated Fat 2.5 g 13%
Cholesterol 5 mg 2%
Sodium 170 mg 7%
Total Carbohydrates 20 g 7%
Dietary Fiber 10 g 40%
Sugars 1 g
Protein 20 g 40%

Protein Blend
Milk Protein Isolate, Whey Protein Isolate

Optimum Nutrition Opti-Bar Protein Bar

O.N. Opti-Bar – Product Summary

  • High Protein: 20g per bar
  • Good Source of Fiber: 8-10g per bar
  • Less than 5g of sugar per bar
  • Offers convenient on-a-go muscle support to assist muscle recovery to get you ready for your next workout
  • Comes in 5 delicious flavors: Chocolate Chip Cookie Dough, Chocolate Brownie, Cookies ‘N Creme, White Chocolate Raspberry, Cinnamon Pecan

Weight loss or weight gain?

Opti-Bar protein bars are designed to assist with the support of lean muscle growth and recovery, as part of a regular exercise and nutrition program.

Protein bars for weight loss are difficult to find. Your best option is finding a high protein, low calorie, low carb protein bar that helps put your body in a caloric deficit each day.

Opti-Bars contain more fat (9 g) than most other protein bars, which pushes up the calorie count (9 calories per gram of fat).

If weight loss is your goal, check out Quest Protein Bars. They contain just 6 g of fat, 20 g of protein and as few as 170 calories.

For weight gain, you’ll need to consume sufficient protein and enough calories from healthy foods to put your body in a daily caloric surplus. For this, MET-Rx Big 100 (30 g protein, 400 cals) could be a better option.

Who are they designed for?

Runners, weightlifters, athletes, or anyone looking for a quick and easy way to increase their protein intake.

When is the best time to eat an Opti-Bar?

While it may not look like one of the best low carb protein bars on the market, with just 20 g per serving, it’s well below the likes of Promax Protein Bars (40 g), thinkThins (25 g), and even RXBARs (22 g).

This makes them a much better option for later in the day, or at times when you’re less active. Perhaps as a mid-morning snack, but preferably not in place of a casein protein shake late at night, which is better for slow protein absorption.

With just 1 g of sugars per bar, you can also be sure that the carbs are coming from a healthy source.

O.N. Opti-Bars vs. Combat Crunch

O.N Opti-Bar
MusclePharm Combat Crunch
Protein: 20 g
Protein: 20 g
Carbohydrates: 20 g
Carbohydrates: 25 g
Fat: 9 g
Fat: 7 g
Dietary fiber: 10 g
Dietary fiber: 12 g
Calories: 250
Calories: 210
Bars per box: 12
Bars per box: 12
Bar weight: 60 g
Bar weight: 63 g
Protein density: 33%
Protein density: 32%
Cost per serving: $1.33
Cost per serving: $1.50

O.N. Opti-Bars vs. MuscleTech Mission1

o.N. Opti-Bar
MuscleTech Mission1
Protein: 20 g
Protein: 21 g
Carbohydrates: 20 g
Carbohydrates: 22 g
Fat: 9 g
Fat: 7 g
Dietary fiber: 10 g
Dietary fiber: 17 g
Calories: 250
Calories: 200
Bars per box: 12
Bars per box: 4
Bar weight: 60 g
Bar weight: 60 g
Protein density: 33%
Protein density: 35%
Cost per serving: $1.33
Cost per serving: $1.75

What flavors and sizes are available?

Optimum Nutrition Opti-Bars have a serving size of 60 g per bar, with 12 protein bars per box.

At the time of writing this review, the best value for money actually from the White Chocolate Raspberry Flavor. These bars were priced at $1.33 per serving, compared to $1.67 for the Chocolate Brownie flavor. That’s why we always recommend calculating the average cost per serving, across all flavors and sizes, before making a final buying decision.

If they’re a similar price when you come to buy (less than $20 per box), it’s actually a great deal. MusclePharm Combat Crunch and MuscleTech Mission1 are both usually more expensive, although they do have a few more grams of carbohydrates and 40-50 fewer calories.


  • Chocolate Brownie
  • Chocolate Chip Cookie Dough
  • Cookies N Creme

  • Cinnamon Pecan
  • White Chocolate Raspberry

Save money with Amazon

If you’re looking to save money on your monthly supplement order, you might want to consider the Amazon Subscribe & Save program.

Subscribe & Save allows you to unlock savings of up to 15% on a wide range of sports nutrition products, including MuscleTech Mission1 Clean Protein.

You can save 5% with a subscription to 1 product, or save the full 15% by subscribing to 5 products, provided they’re all delivered to the same address. The delivery schedule can be set from monthly, up to once every 6 months.

Although 5 products might sound a lot, if you already supplement with a protein powder, multivitamin, creatine, BCAA, and glutamine, the savings can soon add up. But it’s best to order before you run out of your current supplements, because Amazon set the day of the month each order is sent (same day each month e.g. 14th.).

Who are Optimum Nutrition?

With over 30 years in the sports nutrition industry, Optimum Nutrition currently produces some of the bestselling sports nutrition products in the world. These have been designed to improve your strength and recovery, health and wellness, and help increase your protein intake, such as their Gold Standard 100% Whey.

To find out more about their protein powders, bars, ready to drinks, BCAAs, glutamine, pre-workout supplements, creatine, multivitamins, and weight loss products, we recommend our Optimum Nutrition buying guide. This includes a summary of the health benefits you can expect from each product, which sizes and flavors are available, and dosages for the top ingredients.

We’ve also added in-depth reviews and comparisons with other top rated nutrition companies, to guarantee you only buy the best supplement for your fitness goals.

Protein Bar Buying Guide

Review Overview

Overall Review Rating

4 / 5

So, are Opti-Bars the best protein bar on the market?

They certainly tick all the right boxes, with a clean isolate protein blend, great taste, and plenty of protein.

Each bar also contains a high level of dietary fiber (10g), which helps with digestion, and is more than you get with RXBARs (4g), thinkThins (2g) and CLIF Builder's (2g).

Being from a well-established company like Optimum Nutrition, who produce the market-leading Gold Standard Whey protein powder, is also reassuring.

The only downside is that Opti-Bars are available in a smaller range of flavors than Quest Bars, with just a handful of options to choose from.

However, the flavors that are available are delicious, and classic combinations that most people will enjoy. The texture also makes the bars easier easier to swallow, and at 60g in weight, are lighter than bars like Promax Protein Bar (75g) or MET-Rx Big 100 (100g).

Get Awesome Reviews

We Will Only Send You Awesome Stuff!