Which supplements break a fast?
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.
- 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 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 and best electrolytes.
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).
For the bigger picture on fat loss, see how much protein to lose fat.
Products mentioned, with dated prices
| Product | Size | Price | Servings | R per 5 g | R per serving | R per 10 g | Sweeteners |
|---|---|---|---|---|---|---|---|
| ATP Fitness Micronised Creatine Monohydrate | 600 g | R500ATP Fitness shop, Oct 2026 | — | R4.17 | — | — | None |
| Pure Natural Options Creatine Monohydrate 100% 500 g | 500 g | R222Knysna Health (listing via PriceCheck), Oct 2026 | — | R2.22 | — | — | not stated |
| REVIVE Raw Daily Electrolytes, unflavoured (30 sachets) | 30 sachets | R319–R399Faithful to Nature, Oct 2026 | 30 | — | R13.30 | — | None (unsweetened, unflavoured) |
| ATP Fitness Hydrolysed Collagen | 910 g | R950ATP Fitness shop, Oct 2026 | 91 | — | — | R10.44 | None |
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. Read our disclosure.
Related questions
- How do you mix creatine so it dissolves?
- Do you need electrolytes or is water enough?
- Which supplements help during a cutting phase in South Africa?
- What is the best time of day to take collagen?
- Do keto or ketone supplements work?
Sources
- Jäger R et al. (2017) ISSN position stand: protein and exercise. JISSN
- Australian Institute of Sport Supplement Framework: Group A
- Hew-Butler T et al. (2015) Statement of the 3rd International Exercise-Associated Hyponatremia Consensus Development Conference. BJSM 49:1432
Educational information only, not medical advice. Speak to a doctor, pharmacist or registered dietitian before using supplements if you are pregnant or breastfeeding, under 18, taking medication, or living with kidney, liver or heart disease.
Cite this page: Healthnews24, “Which supplements break a fast?”, updated 27 October 2026, https://www.healthnews24.co.za/answers/intermittent-fasting-and-supplements-what-breaks-fast/. Plain-text version: /answers/intermittent-fasting-and-supplements-what-breaks-fast.md