⏰ Intermittent Fasting: What the Latest Research Really Says About Weight Loss and Your Health

Have you heard people talking about intermittent fasting as the “magic bullet” for weight loss or better health? You’re not alone. But with every new diet trend, I like to as: what does the evidence say?

Two major reviews—one just published in The BMJ and another drawing on multiple top-tier studies—have pulled together data from over 99 randomised controlled trials. The goal? To find out if intermittent fasting is more effective than other approaches for weight loss and improving your health.

Let’s break it down.

⏰ What Is Intermittent Fasting?

Intermittent fasting (IF) is a way of structuring your eating time—not necessarily restricting what you eat, but when.

Popular IF styles include:

• Time-Restricted Eating (TRE): Eating within a daily window (e.g. 10am–6pm)
• Alternate-Day Fasting (ADF): Eating normally one day, very little the next
• 5:2 Diet: Eating normally five days, then ~500–600 calories on two days

It’s become a popular choice for people looking to manage weight, improve energy, or support metabolic health.

🔍 What the Research Says

✅ Yes, Intermittent Fasting Works

The evidence is now rated moderate to high quality that IF helps with:

• Weight loss (1–8% of body weight)
• Fat mass reduction
• Lower calorie intake

These results are consistent across studies of overweight or obese adults.

In the BMJ’s 2025 review, which looked at 99 RCTs involving over 6,500 participants:

• All forms of IF (including 5:2, TRE, and ADF) and calorie restriction diets led to weight loss.
• ADF came out slightly ahead of traditional calorie counting, with an average additional weight loss of 1.3 kg.

🧠 What About Health Beyond the Scales?

Intermittent fasting has also shown benefits for several key markers of cardiometabolic health:

• 🩸 Blood pressure: Modest improvements
• 🍬 Insulin resistance and glucose control: Especially with TRE
• 💉 Cholesterol: Some evidence of reductions in LDL and triglycerides, particularly with the 5:2 diet

BUT—and it’s a big but—the size of these changes is generally small, and the clinical significance (for example, reducing heart attacks or strokes) is still uncertain.

Most studies are short-term and don’t report long-term outcomes like cardiovascular events or mortality. So we need more data to say whether IF truly prevents disease in the long run   .

 📉 Is It Better Than Regular Calorie Cutting?

It depends.

The research shows:

• IF is about as effective as continuous energy restriction for weight loss.
• ADF may offer a slight edge in short-term weight reduction.
• Time-restricted eating is especially helpful for controlling blood sugar in people with insulin resistance or pre-diabetes   .

But long-term? Neither strategy clearly outperforms the other.

So the best choice is what suits your life—and what you can stick to.

🩺 What About Side Effects or Risks?

Good news here: IF appears to be generally safe for most adults.

Some people report:

• Headaches
• Irritability
• Hunger in the early adjustment phase

These tend to ease with time. That said, fasting is not suitable for everyone—especially:

• People with diabetes on certain medications
• Anyone with a history of eating disorders
• Pregnant or breastfeeding women
• People with very high physical demands or low body weight

Always check with a healthcare professional before starting a fasting regimen.

🧾 Limitations of the Evidence

Even with all this research, there are still gaps: 

• Most studies are short-term (under 6 months)
• There’s wide variation in fasting protocols
• Long-term effects on heart health, ageing, and mortality remain unclear

In other words, the headlines are promising—but we still need time and better studies to answer the big questions fully.

💡 What Should You Do?

If you’re midlife, busy, and trying to feel more in control of your health, intermittent fasting might appeal. And based on current research, it’s a reasonable and effective approach to try.

Here’s what I suggest: 

• Start gently, with time-restricted eating—maybe an 8–10 hour window.
• Stay hydrated and prioritise protein and fibre when you do eat.
• If you enjoy it and feel well, try it for a few weeks.
• If it makes you tired, dizzy or moody—it’s not for you. And that’s OK.

🧠 The Bigger Picture

 No diet is a magic fix. And fasting isn’t a virtue.

 The strongest health foundations are still:

• Sleep
• Movement
• Whole foods
• Emotional balance
• Relationships and purpose

Intermittent fasting is just a tool—not a health identity. Use it if it serves you, ditch it if it doesn’t.

🎯 Final Thought

 The bottom line? 

Intermittent fasting works. But it’s not better for everyone—and not better than other approaches just because it’s trendy.

You don’t need to skip breakfast to be healthy.

You just need to find what fits your body, your brain, and your life.