Question 1

Does coffee break a fast?

Accepted Answer

Black coffee does not break a fast. It contains negligible calories and does not spike insulin [42]. A latte with milk breaks your fast. Cream breaks your fast. Sugar breaks your fast. Keep coffee plain if you want to maintain the fasted state.

Question 2

Can I take supplements while fasting?

Accepted Answer

Fat-soluble vitamins (A, D, E, K) require food for absorption. Save these for your eating window. Gummy vitamins contain sugar and break your fast. Oil-based capsules may technically break your fast, though the effect is minimal.

Water-soluble vitamins and mineral supplements generally do not break a fast. Electrolyte supplements are actively recommended for extended fasts.

Question 3

Will I lose muscle during intermittent fasting?

Accepted Answer

Daily intermittent fasting (16:8 or similar) does not cause muscle loss when you consume adequate protein during your eating window [43]. HGH elevation during fasting actively preserves muscle tissue. Strength training maintains muscle mass regardless of eating schedule.

Extended fasts beyond 48 hours carry muscle loss risk. Resistance training and adequate protein during refeeding minimize this risk.

Question 4

Is fasting safe for women?

Accepted Answer

Women may respond differently to fasting than men, particularly regarding reproductive hormones [44]. Some women experience menstrual irregularities with aggressive fasting protocols. Starting with shorter fasting windows (12 to 14 hours) and monitoring symptoms allows safe adaptation. Pregnant and breastfeeding women should not practice intermittent fasting.

Question 5

What about exercising while fasting?

Accepted Answer

Low-intensity exercise (walking, yoga, light cycling) works well in a fasted state and enhances fat oxidation [45]. High-intensity exercise or heavy strength training performs better in a fed state for most people. Experiment to find what works for your body and goals.