From time to time I come across people saying that Health At Every Size and/or Fat Acceptance is “anti-science”.
People who say that tend to be making at least one of two mistakes.
1) a. Not knowing the science of why weight loss is so difficult for humans to maintain. At this point I’ve been reading FA/HAES, and mainstream news articles supporting it, long enough that facts like “a weight-reduced person who weighs 150 lbs will have a lower metabolism than a never-fat person weighing 150 lbs” seem like basic, elementary stuff to me, yet I’ll come across people like Rebecca Watson who are generally pretty up on their science who seem to be completely unaware of it–or of the other, probably much more important biological mechanisms that cause people to put weight back on. For a fairly detailed summary of them in one article, see Tara Parker-Pope’s The Fat Trap.
b. They may also not be comparing apples to apples. Some people in Fat Acceptance do make statements that aren’t scientifically accurate. If you compare all of Fat Acceptance to the best, most science-oriented of writing on weight-loss, sure Fat Acceptance will look less scientifically accurate. Duh. If you compare all of Fat Acceptance to ALL pro-weight-loss stuff… I mean, come ON. Cleanses? Detox? Wheat belly? Food combining? Volumetrics? COME. ON.
Plus, see the 1) a.–a lot of people who are fairly scientifically knowledgeable will be completely unaware of reasons besides “they go back to their old habits!” for weight regain, which seems like pretty important knowledge to have if you’re going to discuss weight loss. At least Fat Acceptance people generally know what a set point IS, even if they may not be able to debate the finer points of whether we should really call it a set point or a settling point, whether and how it can be altered, etc. I see plenty of pro-diet people make basic mistakes like conflating a strong genetic influence within an environment to a strong genetic influence across environments (“if BMIs went up in the last few decades and it wasn’t due to genetics, genes must not have much to do with who gets fat in our country today!”), or citing short-term studies of weight loss as proof that people can lose weight permanently (Rebecca Watson AGAIN [I’m picking on her because she’s a relatively-recent example], apparently I can’t link to individual comments, but CTRL+F for “There were only 25 participants in that trial, and they were in the clinic for only 10-12 weeks.” and read the comment just above it) as well.
Pro-weight-loss people have more than their share of cranks (an example via Rebecca Watson!), but people who disagree with them don’t think of their cranks as representative of their side–but they do think of our cranks as representative of our side.
2) You may notice, if you have read to the end of The Fat Trap, that Tara Parker-Pope’s answer for herself is not, “Well, time to do HAES.” It’s, “I’m gonna keep trying, and try to be philosophical about it when I fail.” That’s because, and this is the more important of these two points, deciding whether to do HAES or any of the numerous weight-loss plans or keep eating the Standard American Diet IS NOT A SCIENTIFIC QUESTION. It is NOT the same question as “Which diet is the healthiest?” Not even people deciding to lose weight are necessarily asking themselves “Which diet is the healthiest?” or even “Which diet is the most effective at losing weight?” (I certainly have known people to follow the Atkins diet in order to lose weight who did not believe that it was a healthy diet in general–though their hope was that the unhealthiness of Atkins would be balanced by weight loss, which they naively assumed would persist after they returned to a normal diet.)
How many people arrange everything in their lives, without fail, to be the absolute healthiest possible? Leaving aside whether the causal connection leading from BMI to health is strong, nonexistent, or present-but-greatly-exaggerated, people make decisions all the time about when to try to minimize a health risk and when it’s not worth bothering about. People who work the night shift are not anti-science. People who work 80-hour-work-week jobs are not anti-science. People who sometimes get drunk on the weekend are not anti-science. People who ride on motorcycles instead of in cars are not anti-science.
Similarly, if I decide that since the canine Lyme disease vaccine may not be super-effective and most dogs who test positive for Lyme disease are asymptomatic, and my income is too low to justify the expense, so I don’t get my dog vaccinated for Lyme disease, that doesn’t mean that I’m an anti-vaxxer anti-science person. (In reality, my dog is vaccinated against Lyme disease.) If I choose to get a Subaru instead of a Prius because I kinda need four-wheel drive, that doesn’t mean I’m a global warming denialist.
People are allowed to make judgment calls on how much energy they want to sink into a given health project, and what way of approaching health will be the most resource-efficient and give them the most bang for their buck. They are allowed to decide that focusing on getting the right amount of sleep, eating a balanced diet, getting a decent amount of movement, and drinking moderately are the things they should focus on for their health, and focusing on weight loss too would be a higher investment of resources with a lower rate of return. (To be fair, many of the “HAES is anti-science” people will admit this point, but as a general reminder) They’re also allowed to not focus on health at all!