Protein bars offer a convenient way to top up your protein intake when on the move – but from the multitude of brands and flavours out there, how can you tell which taste great, are healthy enough to eat regularly and deliver the protein punch you need?
To answer that, the first thing to understand is just why eating protein is important. “Protein plays a functional or structural role in all our cells,” explains Tom Clifford, a sports nutritionist and lecturer in physiology and nutrition at Loughborough University. “It’s principally involved in growth and repair, but it provides us with energy, too.” Put simply, protein is essential for your body’s everyday functioning and immune response. After working out, it’s what your body uses to build your muscles.
Clifford recommends 0.7g of protein per kg of body weight for the average adult, in line with guidance from the British Nutrition Foundation. While you should be aiming to get enough protein from whole food sources in your diet, protein supplements can help boost your intake if you’re working towards specific fitness goals.
The next question to ask is how much protein your bar should contain, especially when products range from 5g to around 25g. “If your goal is just to supplement your protein intake, then any amount will contribute to that,” says Clifford. “If you want to build muscle I would suggest around 20g of protein in a bar, or, if you’re lighter, 15g would be sufficient – however, you can’t build bigger muscles just by consuming more protein. You need a stimulus such as weight training.”
Which protein bars are healthiest?
This depends on your definition of ‘healthy’. Many protein bars boast an incredibly low sugar content – for instance, less than 3g of sugar in a bar that contains 20g of protein – because they contain artificial sweeteners. So, if your idea of a healthy bar is one that contains as few highly processed ingredients as possible, then you may have to reconcile yourself to a higher proportion of sugar and carbohydrates.
Although it is generally better to avoid unnecessarily processed ingredients, it’s likely that your protein bar will contain a processed form of protein – but that doesn’t have to be a bad thing. “Bars with protein as the dominant macronutrient will always contain some kind of powder or processed protein source,” says functional medicine nutritionist Steve Grant, as whole food proteins contain more naturally occurring sugars. “Whole food sources of protein, such as nuts and dates, might provide 10g of protein, but then your bar would also contain 15g of sugar and 25g of carbs.”
Clifford agrees: “Processed protein doesn’t necessarily mean low quality. Whey protein, which is derived from milk, is a very high quality source of protein even though it’s processed.” Plant-based protein sources commonly used in bars include soy, rice and pea protein.
Whichever bar you choose, it’s a myth that increasing your protein consumption (within your recommended energy intake) will cause you to gain weight. In fact, as nutritionist Jenna Hope explains, ensuring you eat enough protein can actually help you maintain a healthy weight: “Protein can be beneficial for balancing blood sugar levels and limiting energy crashes, as it helps you to feel fuller for longer,” she says. “Increasing your protein consumption within the realms of your required energy intake will not cause weight gain.” So, within reason, don’t stress too much about the calorie count.
The nutritionists I spoke to reiterated that protein bars should supplement your protein intake, rather than acting as a replacement for a healthy diet that includes whole food protein sources, and shouldn’t be thought of as a ‘healthy snack’. As a rule of thumb, look for a short, recognisable ingredient list but, as protein bars are a convenience food, accept they’re not going to be totally free of sugar and artificial additives.
What about sugar?
If you’re looking for a bar that has protein as the dominant macronutrient, less sugar and fewer calories, then it will contain some additives. As Clifford says: “It’s impossible to avoid both sugar and sweeteners – you’re going to have one or the other, or the bar would taste terrible.”
However, there are certain red flags to look out for when you scan the ingredients label. Sugar alcohols (polyols), which are artificial sweeteners, are not digested by your body in the same way as other ingredients and can cause digestive issues. “Large amounts of polyols, such as maltitol and sorbitol, can have a negative impact on gut symptoms, especially if you suffer with IBS,” says Hope.
When should you eat a protein bar?
It’s easy to get wrapped up in the timing of consuming protein pre or post-workout, but the experts are in agreement that it doesn’t matter exactly when you eat it.
“You want to look at your protein intake over a whole 24-hour period – it’s no use just eating a very large amount of protein at breakfast and then not having much for the rest of the day,” says Clifford. “Having a good quality protein source every few hours is a good way to look at it.”
So, which is the best protein bar for you? We pored over ingredient lists and taste-tested bars from 15 brands. Here’s what we found, starting with our overall favourite…
1. CLIF Builders Protein Bar (Chocolate Mint Flavour)
£27.76 for 12, Amazon