Intermittent fasting — what does the latest research say?

Intermittent fasting has been one of the most-tried diets of the past few years. It’s appealing because it needs no special foods and the rules are simple. But recent research has been split on whether it’s “more effective than an ordinary diet”.

What are the methods?

The most widely used is 16:8 — commonly skipping breakfast and eating from lunch until 8 pm.

What recent research says

An analysis by an international research team published in 2025 pooled data from 22 clinical trials and 1,995 people. It found no meaningful difference in weight loss between intermittent fasting and ordinary dietary approaches such as calorie restriction. The difference in weight-loss rate between the two was just 0.33 percentage points.

Head-to-head studies showed much the same. At 2 months and 6 months, the intermittent fasting group lost about 4.4 kg and 7.4 kg, and the calorie restriction group about 4.2 kg and 7.0 kg — effectively the same.

Not every study agrees, though. A time-restricted eating study of 197 people with overweight or obesity reported greater weight loss than in a group receiving standard care alone, especially when people ate earlier in the day. It’s still an open debate.

If it works, why?

When people lose weight with intermittent fasting, it’s mostly because a shorter eating window naturally reduces total intake. It isn’t special metabolic magic — it’s simply one of the “ways to end up eating less”.

This matters because if you eat more than usual within those 8 hours, you won’t lose weight. That’s actually a common way it fails.

Who it suits

• People who rarely ate breakfast anyway — it’s close to what they already do
• People who prefer simple rules — if managing time feels easier than counting calories
• People who tend to overeat at night — setting a cut-off time cuts late-night snacking
• People short on time to prepare food — fewer meals means less to deal with

Who it doesn’t suit

• People with diabetes or taking blood-sugar medication — there’s a risk of low blood sugar
• People who are pregnant or breastfeeding
• Anyone who has or has had an eating disorder
• Teenagers under 18
• People with gastrointestinal conditions
• People who do high-intensity exercise — it becomes hard to spread out your protein

Especially for anyone with a history of eating disorders, the time-restriction rule itself can feed an obsession with food and lead to bingeing.

If you do it, do it like this

1. Start with the gentlest versions, 12:12 or 14:10
2. Check your total calories within the eating window too — keeping the hours but bingeing defeats the point
3. Split your protein across two meals — with fewer meals it’s easy to miss your target
4. Drink plenty of water during the fasting hours
5. Stop if dizziness or poor concentration continues

In short

Intermittent fasting is one of several ways to lose weight, and right now there isn’t enough evidence that it’s especially better than the others.

So the question isn’t “does it work better?” but “is it easy for me to stick to?”. If skipping breakfast suits you, it can be a good choice; if you need breakfast to get through the day, there’s no reason to choose it.