Does Intermittent Fasting Work?
A wonderful tale of conflicting headlines
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If you’ve been reading the diet news recently, you’ll have seen a huge amount of hubbub over intermittent fasting (IF), the dietary regimen where, shockingly, you eat less food.
That’s an oversimplification of the diet, obviously, but also in essence what you do — intermittent fasting diets restrict your eating by making you eat only at certain times or in certain patterns. So, for example, you might skip breakfast and lunch and only eat in an 8-hour window during the evening, or you might fast entirely on certain days of the week.
And, depending on which headlines you read, the diet is either pretty effective and well-liked, or a total waste of time. This is genuinely wonderful, because based on the evidence both of those ideas are right, and they’re also both wrong. Intermittent fasting is the Schroedinger’s cat of dietary interventions, both working and not working at the same time!
Well, kind of. Let’s look at the science.
Fasting For Science
The study in question is a fantastic randomized controlled trial where the researchers divided 300 people into three diet groups and compared them over the course of a year. The participants either received normal, boring diet advice in a 20-minute consultation, or had the same 20–minutes but were told to do IF instead, or had the initial IF consultation plus 6 weeks of group coaching as well.
Now, this might not sound like much of an intervention — it’s certainly not what we’d usually consider when thinking about large randomized trials — but it’s actually a stroke of genius. A single consultation with a dietician, or a consult plus six weeks of groups sessions, is what’s often offered at non-specialist clinics. If you go to your primary care doctor, chances are this is the sort of care you’ll get*, which makes testing it all the more important.