One of the reasons that I’m no longer interested in attempting weight loss is that my review of the literature informs me that it simply has no basis in evidence as being an effective way to either lose weight or become more healthy (which are two separate things). When I say that, people often object insisting that there are studies where people have lost weight.

The problem is that any old research where a couple of people lost weight won’t do (go ahead, review the literature. I think you’ll be shocked to find how often the average participant lost a few pounds, gained back half of it before they stopped tracking, and then the authors declare the study a success.)

The research we would need for weight loss to meet the criteria of an evidence-based medical intervention is twofold. First, we would need a study where the majority of the participants lost the amount of weight that we are told we need to lose to change our health and maintain that weight loss long term (over 5 years). If we had those studies – and we don’t – we would then need some proof that weight loss actually caused health improvements – and this study already brings that into question.

This rules out the National Weight Control Registry because they’ve chosen to study 10,000 people who experienced weight loss while completely ignoring the up to 800,000,000 failed attempts that happened in the same time frame. Then they just look for things that the 10,000 have in common. So when they say things like “eating breakfast contributes to weight loss” what they actually mean is that they asked the 10,000 people who succeeded what they did, and a majority of them said that they ate breakfast. Note that they didn’t ask how many of the up to 800,000,000 people who did not lose weight also ate breakfast – that would be important information to have since if a majority of the people who didn’t lose weight also ate breakfast then breakfast may have absolutely nothing to do with it.

Imagine if I got together everyone who had survived a skydiving accident when their parachute didn’t open and started looking for things they have in common. Even if every single one of them wore a green shirt and had oatmeal for breakfast, I cannot say that wearing a green shirt and eating oatmeal will allow you to survive a skydiving accident, nor can I ethically start Ragen’s School of No Parachute Skydiving “free green shirt and oatmeal with every jump!” When your entire sample is a statistical anomaly, your research is useless. When all you’re looking for is random coincidence among a select group of outliers, you’d be better off using your research money on lottery tickets.

Other times, people bring up studies where phase 1 was weight loss and phase 2 was maintenance, the study lost between 40% and 70% of participants during or after phase one, and then the researchers continued on as if the remaining people were the complete study group. Not ok. Why did all of those people quit? How will their experience be accounted for? Often the remaining subjects start gaining back the weight they lost so that at the end of phase 2 the average participant has gained back half of their weight with a net loss of less than 10 pounds. Or they only follow up for a year or two when we know that most people gain their weight back by year 5.

People list study after study and all of them have one or more of the above problems, which I or someone else in the discussion points out. At that point, the person listing the studies often gets frustrated and says something like “Why don’t you like my studies?” or “You just don’t want to believe.” If they examined it, I think they’d find that their frustration isn’t with me, it’s with the fact that they’ve been sold a lie and they bought it at full retail price.

I certainly know that frustration, when I did my first literature review of weight loss research I expected to find that all diets worked – I was just looking for the “best” one, the one that had the most solid success. I was so shocked at what I found that I read through all of the literature again. I simply couldn’t believe that this thing – weight loss – that had been marketed to me more aggressively than anything else in my life had no basis in evidence. I couldn’t believe that doctors had been giving me an intervention which had been shown repeatedly to almost always end in failure, and the majority of time had the exact opposite of the intended result. When I found out that there weren’t even any studies that showed that weight loss caused changes in health I was just stunned.

It took me a lot of time and a lot of work to accept the truth. It was hard to find out that I’d been lied to (on purpose and inadvertently), it was hard to find out that the thing that I’d been promised would solve all of my problems was never going to happen. In many ways, at least for me, Health at Every Size was about giving up, but that’s what I do when I find out that I’ve been harboring a mistaken belief. That’s what scientists (well, good scientists) do when their research does not support their hypothesis (however strongly held or widely believed it might be.) They don’t suspend the rules or research and logic and argue for a belief that they can’t support with evidence.

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