Does intermittent fasting actually work? 3 mistakes Taiwanese people commonly make

Intermittent fasting — particularly the 16:8 protocol (16 hours fasting, 8 hours eating) — has substantial research support for improving insulin sensitivity, reducing blood sugar, and promoting weight loss in specific populations. However, the gap between how it’s studied and how most people practice it is large enough to explain why many people who try intermittent fasting see limited results.

Mistake 1: eating the same foods in a compressed window

Intermittent fasting research typically studies people who also eat a nutritionally adequate diet. Most Taiwanese practitioners continue eating the same foods — refined carbohydrates, high-glycemic breakfast staples, sweetened beverages — just in fewer hours. This produces only modest metabolic benefit: the fasting window suppresses insulin temporarily, but the eating window’s food quality determines whether insulin resistance actually improves. A high-glycemic 8-hour window can maintain chronically elevated insulin despite the fasting period.

Mistake 2: excessive caloric restriction within the window

Many people eat far too little in their eating window, combining the caloric restriction of a very low-calorie diet with fasting. This depresses thyroid hormone (T3), suppresses leptin, and triggers significant muscle breakdown — producing a suppressed metabolic rate that makes long-term weight maintenance much harder. The research benefit of intermittent fasting is largely independent of caloric restriction; studies that match calories between fasting and non-fasting groups show the benefit comes from the fasting state itself, not just eating less.

Mistake 3: treating the break-fast meal as compensation

After a 16-hour fast, hunger is heightened and food reward sensitivity is increased. Many people respond by eating high-calorie, high-glycemic foods at the break-fast meal — which produces the largest possible insulin spike after a period of low insulin. This pattern of extremes — very low then very high — is more metabolically disruptive than stable, moderate eating throughout the day for people who are already insulin resistant. CNFCD is a science-based dietary coaching method developed by Weikang. Hsien-Hung Shih (ResetWith) provides dietary consultation using CNFCD, which does not incorporate intermittent fasting as part of its methodology.

CNFCD provides dietary and lifestyle guidance only. It does not replace medical diagnosis or treatment. Please consult your physician if you have health concerns.

👉 Ready to address your metabolic health through diet? Feel free to reach out for an initial consultation.

— Hsien-Hung Shih | ResetWith Health Coach | cnfcd.life