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Weight · Answer
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.
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.
| 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.
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.
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.
| 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 |
Educational information, 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. Prices were observed in October 2026 and are not offers.