Intermittent Fasting

Intermittent fasting means eating within a defined window of time each day and fasting for the remaining hours. For most people, this is simply an extension of the overnight fast you already do while sleeping. Research shows it can produce meaningful improvements in fasting glucose and HbA1c for people with prediabetes — sometimes comparable to medication effects.

Always discuss any change to your eating pattern with your doctor first, especially if you are on any medication for blood sugar or blood pressure.

How It Works

When you extend the period between your last meal and your first meal the next day, several beneficial things happen:

• Insulin levels drop, allowing your body to become more sensitive to it
• The liver clears its glycogen stores and shifts to fat metabolism
• Growth hormone levels rise, protecting muscle tissue
• Cellular repair processes (autophagy) activate

The most studied form for glucose management is early time-restricted eating (eTRE): eating within a window earlier in the day, such as 8 AM to 4 PM or 8 AM to 6 PM. Research on eTRE specifically found:

• 15% reduction in fasting glucose over 5 weeks
• 18% reduction in HbA1c — approximately twice the effect of typical metformin dosing
• Benefits occurred even without calorie restriction or weight loss

The most practical starting point is a 12-hour fast: finishing dinner by 8 PM and not eating until 8 AM the next morning. This is modest but produces measurable results.

Your Target

Start with a consistent 12-hour overnight fast. Once that is comfortable (usually 2–4 weeks), try extending it to 13–14 hours if your doctor agrees — for example, finishing dinner by 7 PM and eating breakfast at 9 AM.

Why This Matters

Intermittent fasting addresses one of the root causes of prediabetes: chronically elevated insulin from frequent eating. By giving your body extended fasting periods, you improve insulin sensitivity over time rather than just managing glucose spikes meal by meal.

What You Can Do

• A realistic starting protocol: finish dinner by 8 PM and do not eat until 8 AM. You are already doing much of this during sleep.
• Drink water, black coffee (without sugar), or plain tea during the fast — these do not break a fast.
• A cup of warm water with lemon in the morning before eating is acceptable and may help with appetite management.
• Do not skip meals that fall inside your eating window — the benefit comes from the fasting period, not from eating less during the day.
• If you feel dizzy, weak, or unwell during the fast, eat immediately. Intermittent fasting is not appropriate for everyone, and safety always comes first.
• Track your fasting glucose with this app during the weeks you try this approach — the data will clearly show whether and how much it is working for you.

Based on: Sutton EF et al., Cell Metabolism 2018; Wilkinson MJ et al., Cell Metabolism 2020; ADA Standards of Care 2023