Is Intermittent Fasting Safe for Everyone?

One of the most common questions I get is:
“Hannah, what do you think about intermittent fasting?”

And I get why, it’s everywhere lately, from podcasts to dinner tables. But before we dive in, let’s rewind a little.

Intermittent fasting (or IF) isn’t new. People have been fasting for centuries for religious, cultural, or health reasons. Today, it’s being used as a weight management tool. But here’s the twist, it’s not about what you eat, but when.

There are different styles:
⏰ 16:8 (16 hours fasting, 8 hours eating)
📆 5:2 (five regular days, two reduced-calorie days)
🔁 Alternate-day fasting
…even the extreme OMAD (one meal a day).

Sounds simple, right? Let’s break it down.

🌿 Why It Works for Some

1. Flexibility – You can choose the style that fits your routine.

2. Weight Loss – Shorter eating windows can naturally reduce calories.

3. Insulin Sensitivity – IF may help your body use insulin more efficiently.

4. Growth Hormone Boost – Some studies show it supports fat metabolism and muscle repair.

🍂 The Catch: What to Keep in Mind

1. Hunger & Cravings – Expect energy dips or irritability if meals aren’t balanced.

2. Not for Everyone – If you have diabetes, low blood pressure, take meds, or have a history of disordered eating, IF can backfire.

3. Social Hiccups – Skipping brunch or pushing dinner late can feel isolating.

4. Hormonal Effects (Especially for Women) – Extended fasting may affect menstrual cycles, energy, or fertility.

🚦 Why “One-Size-Fits-All” Doesn’t Work

Here’s the honest truth: what works for one body might not be safe for another.

Skipping meals without knowing your body’s needs can lead to:

- Energy crashes and brain fog

- Nutrient deficiencies

- Hormonal imbalances

- Binge-eating later on

That’s why the role of a registered dietitian isn’t to tell you not to try intermittent fasting, it’s to make sure you’re doing it in a way that’s safe, effective, and sustainable for your lifestyle.