Should I Be Eating Protein Bars?

Protein supplements aren’t just for hardcore bodybuilders anymore. While the muscle-bound are dipping into big buckets of protein powder to refine their ripped physiques, the everyday health-conscious consumer can now grab a growing variety of protein-laden bars, snacks and drinks from the store shelves. But are protein-enhanced products good for those of us who aren’t slaves to the weight room? We asked Dr. Ruth MacDonald, Iowa State University, and nationally renowned nutrition and fitness expert Dr. Liz Applegate, Director of Sports Nutrition at the University of California-Davis.

What is the purpose of protein?

Dr. Ruth MacDonald:

Protein has several functions in the body including serving as structural components of muscle. All proteins are made up of amino acids. Humans can generate some of the 20 different amino acids; those that we can’t produce are called ‘essential amino acids’ and must be consumed from food. ‘High-quality’ protein sources are identified by nutrition scientists as those that contain all the essential amino acids in the amounts needed by humans. The highest quality proteins come from animal sources – eggs, meat and milk.

Dr. Liz Applegate:

Protein makes up 18 to 20 percent of your body weight and there are 10,000 different proteins in a human body. They are anything from a structural protein like collagen, which literally is the glue that holds you together, to muscle protein, immune cell protein, fluid balance proteins – the list goes on and on. And these proteins don’t live forever; your body makes them and then they break down. You’re constantly refreshing proteins in your body.

Why do athletes consume additional protein?  

Dr. MacDonald:

Proteins are important for the elite body builder. All amino acids must be available when protein synthesis (the process in which cells build proteins) is occurring, in order to promote muscle growth. So, consuming small amounts of high-quality protein is all that is needed to meet the demands of exercise-induced protein synthesis.


There are many products available that contain protein mixtures and amino acid blends that are marketed to bodybuilders. These can be effective if they provide the right balance of essential amino acids, but taking individual amino acids or mixtures with herbal stimulant ingredients can be dangerous.

Dr. Applegate:

Well, they actually need it. If you look back to ancient Greek athletes they felt the extra protein was going to help give them the same strength that it gave a bear or a deer – the speed and endurance. The research clearly shows that if you’re exercising vigorously – 45 minutes to an hour or more – most days of the week, you need more protein.

Do protein products serve any real purpose for the everyday consumer?

Dr. MacDonald:

Consuming high amounts of protein, such as protein powders or drinks, is not needed for most recreational athletes who are meeting their protein needs through food. However, there is increasing evidence that consuming high-quality proteins throughout the day may be beneficial to meet protein synthesis needs in everyone.

Dr. Applegate:

For someone who isn’t going to fix an omelet or have a tuna sandwich or tofu stir-fry to get their protein, eating a protein bar with 20 grams of protein is a reasonable idea. I think both athletes and non-athletes look at these products as offering something magical or unique compared to whole foods and, simply put: they don’t. The protein in a protein bar or shake actually comes from food. You’re paying more per pound for what you’re getting in the supplement, but it’s offering you convenience.

How much protein should the average adult consume?

Dr. MacDonald:

The recommended intake of protein is based on body weight: 0.8 grams of high-quality protein per kilogram of body weight each day. This is a generous recommendation and includes a large safety margin for most healthy people. That translates to 58 grams of protein for an adult male weighing 160 pounds and about 47 grams per day for an adult female weighing 130 pounds.


For people that consume animal foods, meeting their protein needs is easy. For example, two eggs contain 13 grams, a large hamburger has 25 grams, a pork chop contains 45 grams – totaling 83 grams! Vegetarians, however, will need to be very careful to consume complementary protein foods like beans and rice to provide missing essential amino acids.

Dr. Applegate:

I look at a range of 50 to 80 grams per day. For someone who has a regular fitness routine, I up that to 70 to 100 grams because exercise does increase protein needs. Most Americans consume roughly 70 to 100 grams. We do get more than we need and I’m of the opinion that we get a disproportionate amount in our evening meal and not enough in the morning meal. So aiming for 25 grams or so at each meal is best – rather than eating a gigantic piece of meat or chicken breast in the evening and getting 40 grams of protein. 

Are there consequences to consuming too much protein?

Dr. MacDonald:

More is not better when it comes to protein, because protein contains nitrogen. Unique to protein, the nitrogen can’t be stored and therefore, excess nitrogen must be excreted through the kidneys, which can lead to dehydration. Also, when calorie intake (whether in the form of protein, carbohydrates or fats) exceeds energy output, the body stores the extra as fat.


There are several diet plans that recommend consuming protein rather than carbohydrates. The body needs carbohydrates to provide quick energy and so a healthy diet should not eliminate carbs completely. This is especially true for athletes who need carbohydrates to replenish glycogen stored in muscle after exercise.

Dr. Applegate:

If a healthy person is 20 to 50 percent over the requirement, it’s not a big deal. Where I see a problem is with people who are excessive protein eaters – for example, those who eat a couple of cans of tuna and several eggs whites daily. This overconsumption of protein leads to the exclusion of other foods that they need in their diet, like three cups of veggies and three pieces of fruit, daily. And while canned tuna is a favorite for people looking for a cheap, high-quality source of protein, it’s important to limit your intake to no more than three cans per week because of mercury levels.

What are the best protein sources?

Dr. MacDonald:

Meeting protein needs is essential for athletes and non-athletes alike. All muscle is constantly being broken down and replaced. That’s why all adults need to consume high-quality protein foods throughout the day. This can be as simple as eggs or yogurt at breakfast, lean meats or cheese at lunch, and meat or high-quality vegetable proteins (rice and beans, for example) at dinner. Athletes may benefit from consuming moderate amounts of protein after workouts – and a protein beverage or even chocolate milk can be effective.

Dr. Applegate:

The question I pose to people is ‘what else does that food offer?’

    • For meats like chicken, turkey, beef and pork, you’re getting a high-quality protein with the essential amino acids your body needs, but you also get the good absorbable trace minerals like iron and zinc, which some people don’t get enough of in their diet.
    • Dairy sources are excellent because, along with protein, you get calcium, riboflavin and vitamin D.
    • Vegetarian sources of protein like tofu provide some really heart-healthy fats and some cancer-fighting compounds called isoflavones.
    • Eggs top the list as the best source of protein because they have the profile of amino acids that exactly match our needs.

My recommendation is not to choose one source over the other, but rather, to choose a variety.

Need some protein after a busy day or grueling workout? Try these protein-packed recipes from the folks at! Click the picture or the link to view the recipes. (Photo credits:


Chicken Cordon Bleu Burger – 29 grams



Tomato and Spinach Dinner Strata – 20 grams



Spinach Salad with Steak and Blueberries – 29 grams

Day 216: Snacking” by Sodanie Chea is licensed under CC BY.