Are protein bars good for you?

Telegraph

a day ago

Protein repairs and builds tissue, reduces hunger and may even help with weight loss. Add the magic phrase 'high-protein' to the packaging of bread or yogurt – or even ice cream and Snickers bars – and suddenly they wear a health halo.
The global protein bar market was valued at £4.3 billion in 2024 and, according to Fortune Business Insights, that figure is set to soar to £5.6 billion by 2029. Once niche products sold in health food shops to athletes and bodybuilders, they are now available everywhere, in supermarkets, convenience stores, even Poundland.
The potential benefits of protein bars
A protein boost
Support for exercise routines
Better for your health than a normal chocolate bar
We all need protein to be healthy and to maintain our muscle mass (or indeed add to it, if you're fond of lifting weights, or strength training). The average adult in Britain consumes 76g of protein a day (the recommended amount is 0.75g per kilogram of body weight), a sum easily reached through a diet that includes meat or fish.
However, someone looking to build muscle needs to consume at least 1.6g of protein per kilogram of their bodyweight each day, and this can be hard to get in through eating alone. Vegetarians and vegans might also struggle to hit their protein goals, and many older adults also struggle to eat enough protein.
This is where protein bars can help. The standard bar can contain around 20g (about three quarters of an ounce) of protein, providing about a third of the recommended daily protein intake for an average sized person in the UK. Research into the benefits of eating protein bars is limited, but a 2021 study of elite athletes concluded that consumption of protein bars improved the athletes' 'physiological adaptation after training'.
Protein bars can also be a tasty sweet treat in moderation. For those with a sweet tooth, it may prove a better option than a simple chocolate bar, as a treat.
The potential downsides of protein bars
May be high in sugar and saturated fat
High calorie-to-protein ratio
Often low in fibre and micronutrients
Usually ultra-processed
While these often tasty bars pack a protein punch, most are also high in calories and many are high in unhealthy saturated fats. Most are also classed as ultra-processed foods.
Studies into their health benefits are limited. Naveed Sattar, a professor of cardiometabolic medicine at Glasgow University's School of Cardiovascular and Metabolic Health, says: 'There is lots of good evidence that protein suppresses appetite. But the question of whether protein bars are health-giving in and of themselves has not been trialled yet.'
Rob Hobson, a sports nutritionist and the author of Unprocess Your Life, adds: 'People are obsessed with protein, but they confuse 'high protein' with 'healthy' because they think protein is the most important nutrient to get in your diet.'
He describes many protein bars as a 'mishmash of weird ingredients, bindings, sweeteners and emulsifiers, which some studies suggest negatively affect gut biome. They are an ultra-processed food, whatever way you look at it.'
Common ingredients include maltitol, a sweetener that can cause diarrhoea, whey protein, which can cause bloating, sucralose, which can impact on the variety of gut bacteria, and inulin, which is a fibre source that can lead to bloating.
One study by researchers at Arizona State University published last year in the Journal of Functional Foods concluded that daily ingestion of protein bars can 'significantly' increase fat mass.
Not all protein bars are made equal, however. A 2006 study compared the effects that high protein and high-fibre bars had on glucose and insulin levels in a cohort of 23 women, and found that glucose and insulin responses – and peak glucose levels – were significantly lower in those who ate bars high in protein and fibre compared with women who had eaten bars high in fat and sugar. A morning high-protein bar also reduced energy intake at lunch by 5 per cent.
Regardless, Priya Tew, a specialist dietitian from Dietitian UK, says that, generally, most of us get enough protein from our regular diets, and recommends against relying on ultra-processed snacks, which most top-selling protein bars are.
'We all need protein in our diets; it is a very important macronutrient, but so are carbohydrates and fats. The key is not to focus on just one nutrient or food group but to aim for balance. The average person is not going to need protein bars daily, but this does not mean that all protein bars need to be excluded, or that all of them are equally nutritious.'
How much protein should you eat a day?
The average adult needs a protein intake of 0.75g per kilogram of body weight, per day, in order to maintain their muslce mass. For the average man in Britain, this would mean eating about 64g of protein a day, equivalent to nine large eggs or two chicken breasts. The average woman needs to eat around 53g of protein per day, or the amount of protein in eight large eggs or around one and a half chicken breasts.