Protein bars are a convenient way to get more of the muscle-building macronutrient, but they often contain other ingredients that may not be so healthy.
Here are four common additives experts say to avoid—or at least watch for—when choosing a protein bar.
“Many bars are marketed as ‘healthy’ or ‘high-protein’ but contain sugar amounts similar to candy bars,” Morgan Walker, MS, RD, LDN, a sports dietitian and adjunct professor at Lebanon Valley College, told Health.
Added sugar is what it sounds like: sugar not naturally found in food but is added during processing. For athletes and other very active people, added sugar can help replace depleted glycogen stores and provide quick energy during training, Walker noted.
“But for most people without high-calorie or high-training demands, it contributes excess calories without providing significant nutritional benefit and may lead to energy crashes,” she said.
Check the ingredients list for added sugars, which may appear as:
Keep in mind: The Centers for Disease Control and Prevention recommends that added sugars make up less than 10% of your total daily calories. On a 2,000-calorie diet, that’s no more than 200 calories, or about 50 grams (roughly 12 teaspoons) per day.
So ideally, your protein bar should have no more than 5 to 8 grams of added sugar, according to Ontario-based registered dietitian Avery Zenker, RD, MAN.
How to sweeten protein bars so they taste good is a bit of a conundrum: Too much added sugar is a concern, but experts say artificial sweeteners can be problematic, too.
“Sugar alcohols in excess can cause gas, bloating, and diarrhea in some individuals,” Alex Larson, MS, RD, LD, a Minnesota-based endurance sports dietitian, told Health.
Some studies have also linked artificial sweeteners to a higher risk of conditions like diabetes and heart disease—though the research isn’t conclusive.
Common artificial sweeteners include:
- Sucralose
- Aspartame
- Sugar alcohols such as xylitol and erythritol
Stevia, monk fruit, and allylose are natural, sugar-free alternatives with fewer health concerns, Zenker said.
Saturated fats are either animal- or plant-based oils that can increase LDL (“bad”) cholesterol and the risk of cardiovascular disease. In protein bars, these can come in the form of palm oil or hydrogenated oil, Larson said.
They “may be used as a binding agent and [to] improve texture, often in a chocolate coating,” she added.
The American Heart Association recommends that less than 6% of daily calories come from saturated fat, which would equate to no more than 120 calories in a 2,000-calorie diet.
In general, it’s best to look for bars with healthy unsaturated fats from nuts, nut butters, or seeds, Zenker recommended.
Fiber is “often added to improve texture or give the bar a fiber boost,” Walker said—and it’s something we need for basic health, including to aid in digestion.
But too much fiber at once can cause unpleasant gastrointestinal issues, like gas and bloating.
To assess the fiber content in a protein bar, check the ingredients list for processed or isolated fibers, such as chicory root fiber or inulin.
Aim for at least 2 grams of fiber in a protein bar—adults should generally get 22 to 34 grams of fiber per day—but be cautious of bars with more than 10 grams, Zenker said.
When it comes to what your protein bar should contain, experts agreed on two criteria: a short ingredient list and one made up mostly of whole foods.
Specifically, keep an eye out for:
- High-quality animal-based protein: Look for sources like whey, casein, egg, or milk.
- Complete plant-based protein: Bars made with soy, or a combination of pea, brown rice, and hemp seed, provide complete protein and sufficient leucine, which is important for muscle synthesis and repair, Walker said.
- Protein isolates (not concentrates): Bars made with whey isolate or pea protein isolate, for example, tend to be easier to digest and provide more protein per gram, Larson said. “Protein concentrates are less refined, which means you’re getting a lower percentage of protein and sometimes more fillers.”
- Other whole-food ingredients: Nuts or nut butters, coconut, seeds, dried fruit, and oats or other whole grains round out the nutritional profile with vitamins, minerals, fiber, and healthy fats.
- Good protein-to-calorie ratio: Shoot for at least 12 grams of protein per bar, with 7 to 10 grams of protein per 100 calories, Zenker recommended.
