Saturday, February 15, 2020

Saturday Stories: Man-Boobs, Formula, And Shattered Identities

James Hamblin, in The Atlantic, on the bizarre and unfounded man-boob based backlash to plant-based meat.

Hannah Ellis-Petersen, in The Guardian, on how formula makers target the mothers who can least afford it.

Sarah Zhang, in The Atlantic, on DNA testing and shattered identities.

Tuesday, February 11, 2020

Why Service Provision Fatally Confounds All Diet Studies (5:2 Intermittent Fasting Edition)

Last week I posted about a 5:2 intermittent fasting study that demonstrated terrible adherence with a 58% 5:2 drop out rate by the end of year one and where the average loss was 11lbs.

In response, Erik Arnesen shared another year long 5:2 intermittent fasting vs. continuous energy restriction study where the drop out rate at the end of year one was just 7% and the average loss was 20lbs! (and actually I blogged about this one in the past - tl;dr no difference in outcomes but 5:2 participants were hungrier)

If the diets were identical, why the tremendous difference in adherence and weight loss at a year?

Sure, could be different patient populations, but I'm guessing the much larger factor was the service provision. Because at the end of the day that's a huge part of what's being measured in any organized diet study. Not just in terms of how many visits or touch-points a particular program has, or what collateral materials and support they provide their participants, but also the rapport development, motivational ability, and teaching skills of the service providers themselves.

Having led an inter-professional team for 16 years, I can tell you that who you've got helping your patients/participants has a tremendous impact on their outcomes even within the same program's delivery.

So the next time you consider the outcomes of any study's diet arm, a question worth pondering is how much of those outcomes are consequent to the prescribed diet itself, and how much are consequent to the health care professionals administering it?

Saturday, February 08, 2020

Tuesday, February 04, 2020

Year Long 5:2 Intermittent Fasting Study Reports It's No Better Or Worse Than A Horribly Restrictive Diet

I started out planning to write about a different paper - a one year post intervention followup of people who had completed a prior year of being randomly assigned to 5:2 style intermittent fasting (IF) (2 days a week consuming 400-600 calories) vs. continuous energy restriction (typical of eating less daily) which showed that there was no difference between the two, but when I read it I realized the story was in the initial intervention, not the follow up.

The initial intervention involved randomly assigning 332 people to one of 3 dietary interventions:  Continuous (daily) energy restriction (CER), week-on, week-off energy restriction, and a 5:2 intermittent fasting pattern involving 5 days of habitual intake and 2 very low energy diet days each week.

Of the only 146 completers, no differences were found between the diets in terms of weight loss, adherence, change in lipids, or fasting glucose.

And most of that is consistent with other studies of 5:2 IF which have found that it's no better or worse than any other approach when it comes to weight loss and biochemical changes. But what's not consistent is adherence being the same, wherein other studies tend to see more people quitting IF.

Digging the tiniest bit deeper into this two things stand out. Adherence was abysmal for both CER (49% drop out rate) and IF (58% drop out rate). But what was different here was what was involved in the CER arm. Women randomized to the CER arm were aimed at consuming only 1,000 calories daily for a year, while men were aimed at only 1,200 calories daily. That's a life-suckingly low number of calories for anyone to be aimed at and honestly it surprises me that researchers (and peer reviewers) would think that degree of continuous restriction would be worthy of study.

All this to say, that people were just as likely to report adherence to a misery inducing 1,000-1,200 calorie per day diet as they were to a 5:2 IF approach does not reflect well on the enjoyability (and consequently the broad applicability) of 5:2 style diets.

And for the inevitable trolls, I'm not knocking 5:2 IF. If you love it, terrific! Don't stop! But don't anyone expect it's a panacea for all comers.

Saturday, February 01, 2020