Energy Bars vs Protein Bars: Differences, Pros, & Cons

When you are looking for a quick, convenient snack, you might wonder if an energy bar or a protein bar is better.

So, what’s the difference between an energy bar vs protein bar? A protein bar will supply more of its calories from protein than an energy bar, providing a minimum of 10g of protein per 100 calories. On the other hand, an energy bar is lower in protein and provides more calories from carbohydrates and fat.

The right bar you choose to eat depends mostly on the timing (i.e. when you eat it throughout the day).

You don’t want to sabotage your nutrition goals by eating the wrong type of bar at the wrong time, so in this article, I’ll cover:

  • The key differences between energy bars and protein bars
  • The people who should eat protein bars and energy bars
  • The best times to eat either protein bars or energy bars

4 Differences Between Energy Bars and Protein Bars

1. The Protein Content Will Be Higher In A Protein Bar

A high-protein food has at least 10 grams of protein per serving. For a protein bar, I take this guideline even further and recommend that it should provide at least 0.1 grams of protein per calorie.

For example, a protein bar with 150 calories should have at least 15g of protein. A protein bar with 200 calories should have at least 20g of protein.

Energy bars, on the other hand, have a lower protein content. Many energy bars have only 4-5g of protein per bar, and with 150-250 calories per bar on average, they supply less than 0.1 grams of protein per calorie.  

While the few grams of protein in an energy bar do count toward your daily protein requirement, they are not likely to be a significant source of protein the way a protein bar is.

2. The Carbohydrate Content Will Be Higher In An Energy Bar

Compared with protein bars, energy bars tend to have a much higher carbohydrate content. Protein bars have about 20-25g of carbs per bar, on average, while energy bars can have 30-40g of carbs or more per bar. This is because carbs are the body’s preferred source of energy.

There is an exception in bars that are specifically low-carb energy bars, such as keto-friendly bars. Keto-friendly bars are very high in fat instead and can have 15-20g of fat per bar.  This is about double the fat content of the average protein bar (8-10g of fat per bar).

Energy bars often provide a similar number of calories as a protein bar, but since they have less protein (<10g), the calories come from carbs (or fat) instead.

3. Energy Bars Use More Calorie-Dense Sweeteners

To provide more energy from carbohydrates, energy bars are more likely to use calorie-containing sweeteners such as sugar, honey, concentrated fruit juices, dried fruit, and syrups (such as maple, agave, brown rice, coconut, or tapioca syrup).

Protein bars are more likely to contain alternative low-calorie sweeteners such as sugar alcohols (e.g., erythritol or mannitol) or high-intensity sweeteners like aspartame, sucralose, or stevia.  

4. Protein Bars Will Have A Balanced Macronutrient Profile

A protein bar is more likely to have an overall balanced macronutrient profile, with 25-30% of calories coming from protein, 40-50% of calories coming from carbohydrates, and 25-30% of calories coming from fat.

This lines up closely with our usual recommendation in our meal plans to get 30% of daily calories from protein, 40% from carbs, and 30% from fat.

This means that a protein bar is a much better choice to use as a meal replacement since it mimics the macronutrients you would ideally try to get from whole food sources of protein, carbs, and fat.

Because energy bars tend to provide the majority of their calories from carbohydrates, this means that an energy bar should not be used to replace an entire meal. It is much better as a source of energy before or during a particularly intense and/or long training session or an endurance event like a long hike.

Protein Bars

Pros vs Cons of Protein Bars

Benefits of Protein Bars

Protein bars are a convenient and portable source of protein that can provide just as much protein as a scoop of protein powder or a whole food serving of protein (like a chicken breast).  

Protein bars are a great choice as a quick snack before or after a workout or “in a pinch” when you don’t have time for or access to a full meal.

The high protein content of a protein bar can make it very satiating. This can be helpful for someone who is trying to manage a calorie deficit to lose weight, especially if the protein bar replaces a less filling snack like an apple or a candy bar.

On the other hand, protein bars are more calorie-dense than many whole food choices. This can make it easier for someone who is trying to achieve a calorie surplus to eat more calories without feeling as full as eating the same number of calories from whole foods.

Drawbacks of Protein Bars

Protein bars are commercially processed foods that can be easy to overeat. They tend to have a lower water and fiber content than the equivalent amount of whole foods that provide the same calories and macronutrients.

This means that including protein bars can make it easy for a person to overeat and surpass their calorie target for the day. This is a major drawback for someone looking to lose weight.

Plus, the lower water and fiber content also means that protein bars can cause digestive distress, such as constipation. It’s important to get adequate hydration and fiber from other sources, such as whole grains, legumes, fruit, and vegetables, throughout the day to make sure this doesn’t happen.

Protein bars can also cause digestive distress if they are sweetened with sugar alcohols. Other protein bars are sweetened with so much sugar that they exceed the recommended guidelines for added sugar in a day (6 tsp / 25g for women or 9 tsp / 36g for men).

Protein bars have fewer micronutrients (vitamins and minerals) than the equivalent amount of whole foods.

As I mentioned above, protein bars can contain a similar amount of fat, carbs, and protein as what you’d get from a meal with whole food sources. But regularly relying on them as a meal replacement could cause a deficiency of one or more micronutrients.

Who Should Eat Protein Bars?

  • Protein bars are a great choice for individuals who are struggling to meet their protein targets for the day from whole foods alone.
  • They are also a quick and convenient snack option and can “fill the gap” when someone would otherwise reach for a less nutritious processed food option, such as a candy bar.
  • Protein bars can also be an easy way to add additional protein and calories for someone who is trying to achieve a calorie surplus for muscle/weight gain.

When To Eat Protein Bars

Since protein bars provide a balanced macronutrient profile, they are a better choice for a meal replacement than an energy bar.

However, since they do not provide all of the fiber, water, and micronutrients of a meal from whole foods, they should only be used as a meal replacement from time to time and not every day.

My clients often find that protein bars are great for an on-the-go breakfast or lunch choice, especially if options are limited, such as when traveling.

They also make a great mid-afternoon snack if you’re feeling tired and craving something sweet.

Protein bars are also a great choice for a post-workout snack, provided they are not too high in fat (<10g) or fiber (<5g).

Energy Bars

Pros vs Cons of Energy Bars

Benefits of Energy Bars

Energy bars are convenient, portable, and lightweight sources of calories. They are easy to throw in a gym bag or backpack, which makes them perfect for getting a quick snack on the go. They can provide a quick source of energy to serve as fuel for or recovery from a workout.

Because energy bars are so calorie dense (providing a relatively high amount of calories for a small amount of food), they are often not very filling, which is a benefit for someone who is trying to achieve a calorie surplus to gain weight.

This is also a benefit for an athlete who needs a source of energy that won’t make them feel uncomfortably full while training or competing.

Drawbacks of Energy Bars

Energy bars are commercially processed, calorie-dense food products that are often hyper-palatable, which makes them very easy to overeat. Similar to protein bars, energy bars also have a lower water and fiber content than the equivalent amount of whole foods.

These aspects of energy bars make them easy to overeat, which can lead to excess calories.  For someone looking to lose weight, this is a drawback.

When including energy bars in your diet, it’s very important to get adequate hydration and the appropriate amount of fiber to avoid digestive problems like constipation. I recommend 25-28 grams of fiber daily for women and 31-34 grams for men.

Digestive distress can also come from energy bars if they are sweetened with sugar alcohols.

This is less common than with protein bars since energy bars are designed to provide energy in the form of calories. They are more likely to contain calorie-containing sweeteners such as real sugar, honey, concentrated fruit juices, and other syrups (maple, brown rice, coconut, tapioca, etc.).

Also, many energy bars have fewer micronutrients (vitamins and minerals) than the equivalent amount of whole foods. If you regularly consume most of your calories from energy bars, you could end up with micronutrient deficiencies.

Who Should Eat Energy Bars?

  • Energy bars are a great choice for individuals with high-calorie needs, such as people striving to achieve a calorie surplus for bulking or to gain weight for other health and/or performance goals.  
  • They are also a great choice for highly active people who need a high number of calories to even maintain their weight, especially individuals with a large amount of muscle mass and/or athletes with high training loads.
  • Energy bars are also a convenient and portable choice for snacks for people who don’t have time for or access to whole foods snacks, such as when traveling, hiking or camping, or during long shift work or an on-the-go job.

When To Eat Energy Bars

As I mentioned, energy bars tend to be high in carbohydrates. They are a great choice for a pre-workout snack for an intense and/or short training session, as long as they are low in fat (<5g) and fiber (<5g), which can slow digestion and make you feel full or sluggish before a workout.  

Energy bars with a higher fat content will release energy more slowly and are a better choice for longer events, like a hike.

The high carbohydrate content of energy bars can also make them good for post-workout recovery, provided that they still have a moderate fat content (<10g) since you want to keep fats low after a workout.

Since energy bars do not have a balanced macronutrient profile, they are better as a snack and not as a replacement for an entire meal. 

Frequently Asked Questions

Is Eating an Energy Bar the Same as Eating a Protein Bar?

No, eating an energy bar is not the same as eating a protein bar. They have different macro profiles; each is suited to different energy and nutritional needs. Energy bars are more calorie-dense and lower in protein than protein bars. Energy bars are good for fuel & recovery; protein bars make a better “anytime” snack.

Is It Better To Have a Protein Bar or Energy Bar Pre-Workout?

It is better to have an energy bar pre-workout because energy bars are high in carbohydrates, and carbs are the body’s preferred source of energy.  Be sure to choose a bar with low fat and fiber content so the carbs will be digested quickly.  

Is It Better To Have a Protein Bar or Energy Bar Post-Workout?

It is better to have a protein bar post-workout because it is important to combine a lean protein source with fast-digesting carbs while keeping fats low after a workout. However, the fat content of the bar should be <10g so your body can digest the protein and carbs more quickly and use them to recover.

About The Author

Lauren Graham

Lauren Graham is a Precision Nutrition Level 1 certified nutrition coach. She focuses on helping busy professionals balance healthy eating and purposeful movement.  Lauren has a background in competitive swimming and is currently competing as a CrossFit athlete.  She has a passion for training, teaching, and writing. 

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