Are Protein Bars Good For You? The Myths Behind Your Favourite Snack

In the last few decades, protein bars have become a true desk drawer and handbag staple. After a workout, between meetings, on the way to the airport — they're one of the most popular snacks to reach for when we need a quick refuel or while trying to hit protein goals. Right now, the global protein bar market is valued at £4.29 billion, with projections suggesting that number will double by 2034, according to Fortune Business Insights.

But while the industry is booming, there are still big question marks around what’s fact and what’s fiction when it comes to the bars’ nutritional benefits. We asked the experts to debunk some of the most common myths behind bold claims and confusing ingredient lists to answer, once and for all, Are protein bars actually good for you?

Here's what they had to say.

Myth: The calorie count is always what it says

Last year, David Bars took the internet by storm: high protein, low calorie, and according to the masses on TikTok, practically edible Ozempic in a shiny gold wrapper. The company initially positioned the bar and its extreme protein-to-calorie ratio as a type of weight-loss tool before a class action lawsuit, which has since been dismissed, alleged that calorie counts were up to 83% higher than stated on the label and fat content was up to 400% higher.

“Calorie counts on labels are regulated but not exact,” says Rachel Clarkson, nutrigenomic dietitian and founder of The DNA Dietitian. “Rounding rules and ingredient variation — particularly around sugar alcohols — means the number on the wrapper has some wiggle room.”

It’s a useful reminder that protein bars shouldn’t be used for weight management or as a meal replacement. “We need diversity in our diets from whole foods, fruit, and vegetables as our bodies also need antioxidants, micronutrients, carbohydrates, fats, and fibre for a healthy gut,” says Bare Biology’s nutritionist Kirsten Humphreys. “Think of protein bars as a supplement to a healthy diet rather than a replacement for one,” she adds. “They can come in handy when you don’t have time to eat or want a quick protein-rich snack, but avoid getting into the habit of relying on them regularly.” 

Myth: There is no such thing as a UPF-free protein bar

Under the NOVA classification system (the framework used to measure how processed a food is), most protein bars you'll see at the store sit in Group 4: ultra-processed.

“Protein bars often rely on protein isolates, emulsifiers, sweeteners, gums, and stabilisers as they’ve been engineered for shelf-life, taste, and texture rather than nourishment,” says Humphreys, who compares most of them to “eating a candy bar enriched with protein.” And there is a knock-on effect for all sorts of health effects related to high UPF consumption, including risk of type 2 diabetes and cardiovascular issues. New research has even shown that diets high in UPFs can affect fertility – in men a higher intake was associated with reduced fertility, while for women the study showed differences in early embryonic development, including smaller measurements in early pregnancy.

But not all protein bars are created equal, and it's important to really look at what goes into your bar and how it's made. While it's hard to stay away from all processing with these foods, there are some options that are less processed than others. Truvani’s The Only Bar uses seven organic plant-based ingredients like organic cashews, dates, almonds, and semi-sweet chocolate, and no artificial add-ins to keep you fueled while on the go.

For a healthier protein snack, Humphreys also recommends making your own homemade protein bars or balls with ingredients like oats, matcha powder, nuts, dried fruit, and a scoop of quality protein powder. “They might have a lower protein content and a shorter shelf-life, but you know exactly what’s in it,” she says.

Myth: High protein means it’s good for you

Not necessarily. “Some of the more processed bars can look better due to higher protein content, but it’s not always the right choice,” says Humphreys. “Manufacturers often use concentrated protein isolates and add binders and artificial ingredients to hit a high protein mark, which isn’t something our digestive system loves in large quantities.”

Clarkson adds that your genes can play a role too – “those with the AA variant of the FTO [Fat Mass and Obesity-Associated] gene tend to benefit most from a higher protein approach. For everyone else, whole food sources will generally get you enough protein without needing a bar,” she says.

As for the source of protein in your bars? Whey and dairy proteins are among the highest quality, she points out, and plant proteins can work well when properly combined. BodyHealth’s Perfect Amino Brownie Bars uses eight plant-based proteins from a blend of organic fruits and greens. 

Myth: Sugar alcohols are harmless

Turn over almost any “low sugar” or “sugar-free” protein bar, and you'll find sugar alcohols like maltitol, xylitol, erythritol, and sorbitol that provide fewer calories than sugar and don't spike blood glucose in the same way. In theory, that sounds like a win, but there’s a reason Clarkson calls this one of the most common issues she sees in-clinic. “Sugar alcohols are poorly absorbed and can cause bloating, gas, and discomfort – especially in people with sensitive digestion. A bar can look great nutritionally but still not be a good fit if someone has a sensitive gut,” she says. Plus, if your body runs well on carbohydrates, a sugar-free bar might leave you under-fuelled without realising it.

Finally, a “sugar-free” label doesn't always mean low-carb, as that same bar could still contain 45 grams of carbohydrates.

Humphreys recommends checking the actual carb and added sugar content per bar rather than just scanning for the presence of a sugar-free label, which isn’t always the healthier option. Bars like Equip Food's Prime Bar use whole-food ingredients and are free from sugar alcohols. Instead, they get their sweetness from dates and honey.

Myth: Protein bars are just glorified candy bars

Of course you’d want your protein bar to taste like your favourite treats. And there are plenty of products out there that have been created to taste like oh oreos or birthday cake. “Unfortunately, protein bars aren’t always formulated for health or function, and if they are, they’re probably not going to taste like an Oreo,” says Humphreys.

The tell is on the ingredient list. Clarkson’s rule for browsing the protein bar aisle: “If the protein source isn’t one of the first ingredients, it’s not really a protein bar.”

A bar built around sweeteners, coatings, and flavouring with protein added on at the end means that it's more of a sweet treat than a functional food. In terms of what to look for? Aim for 15 to 25 grams of protein from a complete source (whey, dairy, eggs, or a well-combined plant blend), carbohydrates, and no more than 15 g of and under 5 grams of saturated fat, says Clarkson. Humphreys also flags fibre as a particularly useful marker, as it's often the first thing dropped in more processed bars, which goes some way to explaining why they don't keep people full.

The major takeaway?

While protein bars can offer a great, quick dose of nutrients and energy when you need it, it's important to focus on getting the majority of your daily protein from whole foods and other dietary sources. If you're reaching for a protein bar, make sure to carefully read labels and do a quick vetting of the ingredients. They can be great ways to supplement your meals, but shouldn't ever be a replacement for everyday nutrition.