How do I pick a healthy protein bar?
Check calories per bar, then sugar and fat per 100g. To say high protein, protein times 4 must be at least a fifth of its calories. Some sugar-free bars must carry a toilet warning.
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What makes a protein bar high protein?
At least a fifth of its calories must come from protein. “Protein bar” on its own is just a name. By law, a bar can only say high protein if at least 20% of its energy comes from protein.
Labels count protein at 4 kcal per gram. So times the grams of protein by 4, then compare that with the calories.
A 200 kcal bar needs at least 10g of protein. With 6g it can only say source of protein, which needs 12%.
- Below 12 %Too little for a protein claim.
- 12 to just under 20 %Can say source of protein.
- 20 % or aboveCan say high protein.
Sources: Nutrition claims law (1924/2006); Food labelling law (1169/2011)
To work out your share, times the protein by 4, divide by the calories and times by 100. A bar with 20g of protein and 180 kcal comes to about 44%.
Think of the calories as a pizza cut into 5 slices. To say high protein, at least 1 slice must be protein. The other 4 can still be sugar and fat, so check those next.
Do the sum on the next bar you pick up.
Can a protein bar be low calorie or low fat?
Low fat has a set level: 3g or less per 100g. Low calorie is much stricter.
A food can only say low calorie, or low energy, if it has 40 kcal or less per 100g. A 40g bar would need 16 kcal or less.
| On the wrapper | What the law allows | For example |
|---|---|---|
| High protein | At least 20% of calories from protein | A 200 kcal bar needs 10g or more |
| Source of protein | At least 12% of calories from protein | A 200 kcal bar needs 6g or more |
| Low calorie (low energy) | 40 kcal or less per 100g | A 50g bar: 20 kcal or less |
| Energy-reduced or light | Energy-reduced: at least 30% fewer calories. Light: usually at least 30% less of something (25% for salt), and it must say what. | Compared with a similar product, not a set level |
| Low fat | 3g of fat or less per 100g | A 50g bar: 1.5g of fat or less |
| Low sugars | 5g of sugars or less per 100g | A 50g bar: 2.5g of sugars or less |
| Sugars-free | 0.5g of sugars or less per 100g | A 50g bar: 0.25g of sugars or less |
| No added sugars | No sugars or sweetening foods added | Must say “contains naturally occurring sugars” if it has them |
Source: Nutrition claims law (1924/2006)
So for a lighter bar, compare kcal per bar. The NHS warns that a maker’s idea of a portion may be different from yours. Eat two and it’s double.
Sources: Nutrition claims law (1924/2006); Food labelling law (1169/2011)
Searching for a low calorie, high protein bar? Pick the one with more protein for its calories, like Bar A.
How do I check sugar and fat in snack and breakfast bars?
Use the NHS guide per 100g. Every pre-packed food label must list fat, saturates, sugars, protein and salt, and give them per 100g.
| Per 100g | Low | High |
|---|---|---|
| Fat | 3g or less | More than 17.5g |
| Saturated fat | 1.5g or less | More than 5g |
| Sugars | 5g or less | More than 22.5g |
| Salt | 0.3g or less | More than 1.5g |
Source: NHS: food labels
Any red on a front label means high. The NHS says to have those foods less often and in small amounts.
Labels show total sugars, which include natural sugar from milk and fruit. The limit is on free sugars, like added sugar and honey: adults should have no more than 30g a day.
The same checks work for breakfast bars, snack bars and high protein chocolate. Vegetarian? Check the ingredients list and any vegetarian or vegan mark.
Six checks for any protein or snack bar
- Find the calories per bar, and check the portion is what you’ll eat.
- Times the protein by 4. To say high protein, that must be at least a fifth of the calories.
- Check sugars per 100g: 5g or less is low, more than 22.5g is high.
- Check saturated fat per 100g: 1.5g or less is low, more than 5g is high.
- Read the ingredients. They’re listed by weight, biggest first, with allergens in bold.
- Check sugar-free bars for a warning that they may cause loose poo.
Sources: NHS: food labels; Nutrition claims law (1924/2006); Food labelling law (1169/2011)
Are sugar-free protein bars better?
Not always. That toilet warning reads “excessive consumption may produce laxative effects”. By law it goes on foods with more than 10% added polyols.
It means eating a lot may give you loose, runny poo.
Polyols, also called sugar alcohols, are sweeteners used in place of sugar.
Most still have calories. Labels count polyols at 2.4 kcal per gram, against 4 for sugar. One polyol, erythritol, counts as 0.
So sugar-free isn’t always calorie-free. Compare kcal per bar, just as you would for any other bar.
Upset tummy after a sugar-free bar? Check its label for that warning.
Do I even need protein bars?
Most people probably don’t. The British Nutrition Foundation says adults need about 0.75g of protein per kg of body weight a day. That’s 56g for a 75kg man and 45g for a 60kg woman.
On average, UK men already eat about 85g and women about 67g. Some people, like athletes and older adults, may need more.
Food gets you there too. Per 100g, grilled chicken breast has about 32g of protein, almonds 21g and boiled eggs 14g.
Over 40? See how much protein you need after 40. For meals, try high-protein breakfasts.
And see protein coffee, bread and crisps.
When to speak to a GP
Common allergy foods include cows’ milk, eggs, peanuts, soybeans, peas, tree nuts and wheat. Check the bold allergens on every bar. Speak to a GP or call 111 if:
- You think you or your child may have a food allergy. See a GP, and don’t cut foods out without speaking to one first.
- You have diarrhoea for more than 7 days, or bloody diarrhoea or bleeding from your bottom. Call 111 now.
- You still have signs of dehydration, such as dark, smelly pee or peeing less than usual, after using rehydration sachets. Call 111 now.
Call 999 if your lips, mouth, throat or tongue suddenly swell, or you’re breathing very fast or struggling to breathe. The NHS lists these as signs of a serious allergic reaction.
Also call 999 if your throat feels tight or you’re struggling to swallow, or your skin, tongue or lips turn blue, grey or pale.
Call 999 if you suddenly become very confused, drowsy or dizzy, or someone faints and cannot be woken up. The same goes if a child is limp, floppy or not responding like they normally do.
If the person has an adrenaline auto-injector, such as an EpiPen, or an adrenaline nasal spray, use it straight away. Then call 999, even if the person seems better.