Monday, March 11, 2019

Why Fund Or Publish Diet Studies That Have Little Relationship With Real Life?

I'm honestly not trying to be mean, but that was the thought that went through my mind when I read the recently published study, Log Often, Lose More: Electronic Dietary Self‐Monitoring for Weight Loss which purports to explore the relationship between food diary use and weight loss.

Don't get me wrong, I'm a huge proponent of using a food diary. Whether it's tracking calories, carbohydrates, macros, or whatever, there's ample evidence to suggest that tracking helps to maintain new behaviours, but is that what this study showed?

Well it did show that those keeping a food diary and using it more often had greater weight loss during a 24 week behavioural weight loss intervention.

So what's my problem?

I have two (well, two related to this study, clearly many overall).

The first is that the food tracker utilized was web based, and not a smartphone app. It's a minor quibble, but nonetheless, app based food diaries are the norm, why not use them? Given we have our phones wherever we go, but not our desktops and laptops, that might make a real difference to the percentage of people using them (and yes, I realize there are web browsers on phones, but that's just not the same).

I'm guessing the reason a smartphone app wasn't used is that using one would not have provided the researchers with the minutes users spent tracking, which brings me to my second, and more significant, concern.

Apparently, in the first month, successful users (those who ultimately lost more than 5% of their presenting weights) were shown to be using that web based food diary 23-24 minutes daily. And though some of that is likely consequent to learning curve, by month 6 it was still taking them 15-16 minutes of effort to record their daily meals and snacks.

Those are extremely high numbers. Having once done a stretch of 3 years of not missing a single day's use of, first a web based, and then an app based food diary, I can tell you that in short order, it really shouldn't take longer than 2-3 minutes daily to track. The learning curve is at most 2-3 weeks, and once beyond that, useful food diaries keep track of your entered meals and snacks such that re-entering them is a simple as a click.

Or at least that's how it should be.

Which means that the users in this study were either taught the world's least efficient means of keeping a food diary, or the web interface utilized was just awful (or both).

Either way, I'm not sure how the results of this study help much. Because while I'm definitely a believer when it comes to the benefits of food diary use, it would seem to me that what this study actually measured are the outcomes of people so incredibly dedicated to their behaviour change efforts, that they bothered putting up with an awful and time consuming food diary for 6 months.

[for some expanded thoughts from me on keeping a food diary, here's a piece I wrote for Greatist a number of years ago, and for full disclosure, I'm currently closing in on beta-testing our office's own food diary and behaviour change smartphone app]