Intermittent fasting is nothingsauce
So Twitter got supermad when I said the human studies on intermittent fasting are not compelling. Not the anecdotes or n=1’s. The actual human studies.
And instead of “not compelling,” I may have said “nothingsauce.”

Hilarity ensued. I was bombarded with

Hey fam, intermittent fasting is totally awesome & a panacea, but the quality of evidence supporting this in humans is quite low (ie, non-existent).
Please don't hate me for this.
— Bill Lagakos (@CaloriesProper) December 16, 2017

Someone was kind enough to send me all the proof that I was wrong. Here are the 5 non-Varady studies, reviewed.

Tl;dr: as long as you’re not eating like a child, “Eating > not eating. QED.”

Alternate day calorie restriction (ADCR) improves clinical findings and reduces markers of oxidative stress and inflammation in overweight adults with moderate asthma (Johnson et al., 2006)

Study design: n=10, 8 weeks, NO CONTROL GROUP. Every other day they ate 20% of normal and ad lib the other days. This would’ve been much cooler if they included 40% caloric restriction and weight maintenance (WM) control groups. The former to see if ADCR was superior to a similar reduction in energy intake and the latter because people behave differently when their being observed (regardless of which group they’re in) (few studies actually include a WM control group).

Result: body weight declined by 8%. Is that worth having nothing but a snack every other day? How about compared to 40% CR? Nothingsauce?

Oh yeah, uric acid increased and BDNF decreased. So, gout, kidney stones, and cognitive deterioration. Yummy nothingsauce.

The effects of modified alternate-day fasting diet on weight loss and CAD risk factors in overweight and obese women (Eshghinia et al., 2013)

Study design: similar to the above, and also lacking a control group.

Result: BW declined by 7%. 

Critique: same. No control group. Would this have been better than CR or anything else? They basically just say "it's relatively safe;" but it's not, really... and some forms of intermittent fasting can have harmful side effects.

Investigation into the acute effects of total and partial energy restriction on postprandial metabolism among overweight/obese participants (Antoni et al., 2016)

This actually made me laugh. Like, to show intermittent fasting is awesome: this study? Really?


Study design: n=10. 

Three interventions: 

1) normal diet on day 1, blood glucose testing after breakfast on the morning of day 2, ad lib food intake monitored days 2 and 3; 

2) 75% energy restriction on day 1, then same as above;

3) 100% energy restriction (no food) on day 1, then same as above.

Both groups overate on days 2 and 3, but still had an overall 30% deficit compared to group 1. 

Metabolic Mayhem. One day of near or total starvation then two days of bingeing. Sounds healthy, right?

On day two, glucose almost doubled after breakfast in group 2 compared to group 1 and it more than doubled in group 3! And what exactly is this supposed to prove? 

A randomized pilot study comparing zero-calorie alternate day fasting to daily caloric restriction in adults with obesity (Catenacci et al., 2016)

No we’re getting somewhere. Sort of.

Study design: True ADF (no food day 1, ad lib day 2, repeat) vs. a relatively decent control group ~ 400 kcal restriction which was about half of what ADF achieved overall.

Result: every other day no food = same weight loss at twice the energy deficit. Sounds great, right?


And lastly,

Comparison of high-protein, intermittent fasting, low-calorie diet and a heart healthy diet for vascular health of the obese (Zuo et al., 2016)

Study design: from what I can decipher, they all lost weight on the high protein, low cal diet with 1 fasting day per week over the course of 12 weeks, then self-selected* to continue for a year on that plan or switch to a Heart Healthy Diet. HP received some protein supps to help them reach their protein targets (1.8 vs. 1.0 g/kg). *I've mentioned in the past, not a big fan of self-selection. It's supposed to improve adherence, but randomization is a powerful tool.

Result: they all lost ~10% of their initial BW in phase 1, then gained it all back in phase 2. [Just watch how I spin this]: so you need to practically double your protein intake to compensate for intermittent fasting? (that's actually partly true -- as meal frequency declines, protein requirements increase)

There ya have it, folks. Eating > not eating. QED.

. .  .   .     .        .             .                     .

Stay tuned: since BDNF actually declined in the Johnson study (unexpected), I'm following up with a review of intermittent fasting vs. various aspects of cognition, memory, mood, sleep, etc. (I guess this could be considered a follow-up of the Brain Health series).

On another note, I’m actually interested in these eTRF studies -- “early Time-Restricted Feeding,” whereby people have breakfast around sunrise, lunch a few hours later, then dinner 2-4 hours prior to sunset. Usually results in about a 14-16 hour overnight fast.

Will keep you posted.

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calories proper

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