The essentials in 30 seconds
- A good protein bar: at least 15 g of protein, less than 3 g of sugar, around 200 kcal.
- Polyols: maltitol replaces sugar in almost every "low sugar" bar. Excessive consumption may produce laxative effects: one or two bars a day is plenty.
- Cereal bar ≠ protein bar: oat bars are energy bars, rich in carbohydrates, made for long efforts.
- How to use them: a handy snack between meals or after training, not a meal replacement.
Protein bar or cereal bar: not the same thing
13 to 23 g of protein per bar (mostly milk protein), little sugar thanks to sweeteners. For a filling snack or to top up your intake.
Oats, sugar, dried fruit: only 4 to 6 g of protein, but plenty of carbohydrates. For a bike ride, a trail run or a long hike.
Two examples from our shelves: the ESN Designer Oatbar (100 g) provides 6 g of protein and 31 g of sugar, the Oat King Black Series (90 g) 4 g of protein and 36 g of sugar, plus 108 mg of caffeine. They are good bars for long efforts, not protein bars. The two families are listed separately on our site: low-sugar protein bars and energy bars.
Our 10 protein bars compared
Values come from the labels, per bar. The last column gives grams of protein per 100 kcal: the higher the number, the more protein you get for the calories (the method of our protein per calorie chart).
| Bar | Weight | Kcal | Protein | Sugar | Protein / 100 kcal |
|---|---|---|---|---|---|
| Body Attack Carb Control | 100 g | 375 | 45 g | 1.4 g | 12.0 g |
| BioTech USA Zero Bar | 50 g | 179 | 20 g | 0 g | 11.2 g |
| Grenade Carb Killa | 60 g | 217 | 23.3 g | 1.5 g | 10.7 g |
| Barebells Protein Bar | 55 g | 203 | 20 g | 1.7 g | 9.9 g |
| Snickers Hi Protein Low Sugar | 57 g | 217 | 20 g | 1.9 g | 9.2 g |
| Warrior Crunch | 64 g | 239 | 20 g | 2.3 g | 8.4 g |
| Barebells Soft Protein Bar | 55 g | 203 | 16 g | 2 g | 7.9 g |
| SNCK Protein Bar | 45 g | 164 | 13 g | 0.8 g | 7.9 g |
| ESN Designer Protein Bar | 45 g | 186 | 14 g | 0.8 g | 7.5 g |
| Barebells Vegan Bar | 55 g | 215 | 15 g | 0.9 g | 7.0 g |
Label values as of 02/11/2026, for the reference flavour. They vary slightly by flavour: the product page is the reference.
Our takeaway: the Zero Bar and the Grenade Carb Killa are the richest in protein for a normal-sized bar; the Body Attack Carb Control is a big 100 g bar, for big appetites; Barebells is the best compromise between taste and texture, which probably explains why the Barebells Soft is our best-selling bar online. The smaller bars (SNCK, ESN) provide less protein, but fewer calories too.
Our favourite for taste: SNCK
In the table, SNCK isn't the highest in protein (13 g per bar). But if you ask us in store which one we prefer for taste, it's this one, by far. Born in Denmark and still little known here, it's all about texture: soft and creamy, nothing like a dry, dense bar. We were the first to stock it in Luxembourg.
Like a chocolate marshmallow treat: an airy vanilla cream under a crunchy dark chocolate shell. 0.8 g of sugar per bar.
The same recipe as Vanilla Fluff, with coconut flakes.
Like a chocolate-caramel ice cream on a stick: caramel cream, hazelnut pieces and milk chocolate.
The taste of a double caramel ice cream: cookie-flavoured dough, biscuit pieces and caramel white chocolate. This one contains sugar (about 6 g per bar).
Our advice: try all 4 flavours as single bars to find yours, then switch to the box of 12. Discover SNCK.
How to read the label
Aim for at least 15 g per bar. Look at the "per bar" value, not "per 100 g": a 100 g bar will always show more.
Less than 3 g per bar for a "low sugar" bar. The claim "low sugar" is only allowed below 5 g of sugar per 100 g.
Maltitol, xylitol, sorbitol: they bring sweetness without sugar. They count as carbohydrates and are shown as "of which polyols" on some labels.
Some bars add hydrolysed collagen for a softer texture. It counts as protein, but it is less complete than milk protein: check where it sits in the ingredient list.
For protein, only EU-authorised claims count:
Protein contributes to a growth in muscle mass and to the maintenance of muscle mass.
This claim may be used for a food providing at least 12% of its energy as protein: true of all 10 bars in the comparison, not of oat energy bars.When to eat a protein bar?
A protein bar is still a snack: around 200 kcal, without the vegetables, fibre and vitamins of a real meal. It helps you reach your daily protein target, which you can work out with our protein needs calculator.
What about protein cookies?
Lenny & Larry's Complete Cookies are among our best sellers: 16 g of protein per cookie, but also 360 kcal and 30 g of sugar for the whole cookie (113 g). A treat to share in two, not a "low sugar" bar. For a savoury snack, see our protein chips guide.
Vegan?
Most bars are made with milk protein. Vegan versions exist (Barebells Vegan Bar: soy, pea and rice; BioTech USA Vegan Protein Bar): everything about plant protein is in our vegan protein guide.
Tonic Food tip: once you've found your favourite bar, buy it by the box of 12 or 20: it is a little cheaper per bar, and you always have one in reserve.
The questions we get asked in store
What is the best protein bar?
One with at least 15 g of protein and less than 3 g of sugar, in a flavour you enjoy. In our comparison, the BioTech USA Zero Bar and the Grenade Carb Killa are the richest in protein; Barebells is our best-selling bar online. And for taste, our favourite is SNCK.
How many protein bars a day?
One, sometimes two. Beyond that, polyols (maltitol) may have a laxative effect, and a bar does not replace the protein of a real meal.
Do protein bars make you gain weight?
A bar provides around 160 to 240 kcal, like a classic snack. What matters is your total for the day: instead of a pastry, it brings more protein and less sugar; on top of everything else, it adds calories.
Before or after training?
Rather after, or as a snack at another time of day. Before a long effort, an oat energy bar, richer in carbohydrates, is more suitable.
Why can protein bars cause bloating?
Because of polyols such as maltitol, which replace sugar. In large amounts, they may have a laxative effect. If you are sensitive, choose a bar with fewer polyols, such as the BioTech USA Zero Bar.
Are there vegan protein bars?
Yes: the Barebells Vegan Bar (soy, pea and rice protein) and the BioTech USA Vegan Protein Bar, for example.
