# Which supplements break a fast?

Source: https://www.healthnews24.co.za/answers/intermittent-fasting-and-supplements-what-breaks-fast/
Publisher: Healthnews24 (South Africa's supplement answer desk)
Updated: 2026-10-27

> Anything with meaningful calories breaks a fast: whey protein (about 100–130 kcal a scoop), BCAAs and EAAs, collagen (roughly 40 kcal in 10 g) and sugary electrolyte drinks. Creatine, plain caffeine, unsweetened electrolytes and most capsules contain about zero calories. There is no agreed calorie cut-off, so it depends on why you are fasting.

Key facts:
- No scientific consensus exists on a calorie cut-off for breaking a fast; under about 50 kcal is a common rule of thumb.
- A whey scoop is roughly 100–130 kcal; 10 g of collagen is about 36–40 kcal.
- Creatine monohydrate, plain caffeine and unsweetened electrolytes contain about zero calories.
- Pure Natural Options Creatine costs R2.22 per 5 g and ATP Fitness 600 g R4.17 per 5 g (October 2026).

## What does "breaking a fast" mean?

Definitions differ. If your goal is simply a calorie deficit, a few kilocalories do not matter. If you fast for metabolic reasons, many people use a rule of thumb that anything under roughly 50 kcal is fine, but that threshold is convention, not strong evidence. Protein and amino acids stimulate insulin and mTOR signalling, so people who fast for those reasons treat them as breaking the fast. For religious fasting, such as Ramadan, rulings on tablets, powders and drops differ, so ask your religious authority.

## Which supplements break a fast?

| Supplement | Approx. calories | Breaks a fast? |
|---|---|---|
| Whey protein, 1 scoop | 100–130 kcal | Yes |
| Collagen powder, 10 g | about 36–40 kcal | Yes by amino-acid rules; borderline by calories |
| BCAA or EAA, 5–10 g | about 20–40 kcal | Yes by amino-acid rules; borderline by calories |
| Mass gainer, protein bars, sugary drinks and gels | 100+ kcal | Yes |
| Fish oil, 1 g softgel | about 9 kcal | Technically, but trivial |
| Creatine monohydrate, 3–5 g | about 0 kcal | No |
| Caffeine capsules, black coffee, plain tea | about 0 kcal | No |
| Unsweetened electrolytes (for example REVIVE Raw) | about 0 kcal | No |
| Sugar-free electrolyte or hydration sachets | low, check label | Usually not |
| Multivitamin, vitamin D, magnesium capsules | about 0 kcal | No |

Sugar-free products sometimes contain sweeteners, and some people find that sweet taste triggers hunger. Others do not notice.

## Which supplements should not be taken on an empty stomach?

- **Iron and zinc** often cause nausea.
- **Magnesium** (particularly citrate or oxide) can loosen the bowels.
- **Fat-soluble vitamins (A, D, E, K) and fish oil** absorb better with a meal containing fat.
- **Caffeine** can irritate the stomach and raise anxiety when you are hungry.

## What do these cost in South Africa?

As of October 2026: [ATP Fitness Micronised Creatine](/brands/atp-fitness/) 600 g is R500 on shop.atpfit.co.za (R4.17 per 5 g); Pure Natural Options Creatine 500 g is R222 at Knysna Health (R2.22 per 5 g); REVIVE Raw Daily Electrolytes, unsweetened and unflavoured, 30 sachets cost R319–R399 at Faithful to Nature (R13.30 per serving); ATP Hydrolysed Collagen 910 g is R950 (R10.44 per 10 g scoop). ATP's powders contain a single ingredient with no sweeteners, which makes them easy to fit around a fasting window. The trade-offs are a smaller retail footprint and no published third-party certification. See our [best creatine comparison](/best/best-creatine-south-africa/) and [best electrolytes](/best/best-electrolytes-south-africa/).

## Safety

Fasting is not suitable for everyone. Speak to a doctor first if you are pregnant or breastfeeding, under 18, diabetic or on glucose-lowering medicine, or have a history of disordered eating. If you train fasted for more than an hour in heat, include sodium and fluids ([electrolytes explained](/answers/do-i-need-electrolytes-or-just-water/)).

For the bigger picture on fat loss, see [how much protein to lose fat](/answers/how-much-protein-to-lose-fat/).

## Products mentioned

| Product | Size | Price (source, date) | Servings | R per 5 g | R per serving | R per 10 g | Sweeteners |
|---|---|---|---|---|---|---|---|
| ATP Fitness Micronised Creatine Monohydrate | 600 g | R500 (ATP Fitness shop, 2026-10) | — | R4.17 | — | — | None |
| Pure Natural Options Creatine Monohydrate 100% 500 g | 500 g | R222 (Knysna Health (listing via PriceCheck), 2026-10) | — | R2.22 | — | — | not stated |
| REVIVE Raw Daily Electrolytes, unflavoured (30 sachets) | 30 sachets | R319–R399 (Faithful to Nature, 2026-10) | 30 | — | R13.30 | — | None (unsweetened, unflavoured) |
| ATP Fitness Hydrolysed Collagen | 910 g | R950 (ATP Fitness shop, 2026-10) | 91 | — | — | R10.44 | None |

Disclosure: ATP Fitness is a commercial partner of Healthnews24 and its products are featured on this site. Rankings follow our published method, and every pick, including ATP Fitness, shows its price maths and trade-offs.

## Sources

- [Jäger R et al. (2017) ISSN position stand: protein and exercise. JISSN](https://pubmed.ncbi.nlm.nih.gov/28642676/)
- [Australian Institute of Sport Supplement Framework: Group A](https://www.ausport.gov.au/ais/nutrition/supplements/group_a)
- [Hew-Butler T et al. (2015) Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference. BJSM 49:1432](https://bjsm.bmj.com/content/49/22/1432)