A chief contention of Health At Every Size (Linda Bacon) is that human beings can’t lose weight, so even if it would optimal for them to weigh less, there’s nothing to be done about it. Is this true? It’s hard to answer, because the question isn’t very well defined. Bacon admits there are things human beings can do to gain weight, and when they stop doing them, they sometimes lose weight. So if you’re doing those things, you probably can lose weight. And that people have a set range they can move around in healthily, based on diet and exercise, so if you’re at the top of your range now you could lose 20 pounds and still be okay.
On page 143, Bacon very strongly implies that twins maintain the same body weight even when they have very different activity levels, so weight is controlled by genetics. The studies she cites do show that when activity and diet is held constant, two unrelated people will have different health metrics. They also show that when two identical twins have different activity levels or diets, they will have different health metrics (including weight). Oh, and the combined sample size of both studies together is 35 sets of twins. This is where I started to get angry. I get using weak studies that strongly support your hypothesis. I get misleading people about what a study stays to support your hypothesis. But doing both is just…argh. I supported HAES. The actual prescriptions for food are basically the Michael Pollan diet (eat food, mostly plants), and motivation to retrain yourself to like real food rather than hyperprocessed crap. Those goals are good. Those goals are good even if they lead to weight gain, because under most circumstances produce is good for you and cheetos are not (although not all- this Captain Awkward post is full of people for whom carrots trigger intense digestive distress but hamburgers are safe and nurturing. I used to live off of pasta because anything else felt like eating death.)
I did check Bacon’s sources on the claim that people who lose dramatic amounts of weight tend to gain it back within 5 years. That appears to be true, at least in the studies she cited. And yet, she also cited studies showing that activity level affects weight. My explanation is that losing weight is not a thing you do. Your diet and activity level translate to a weight or body fat percentage*. If your current weight is different than that, it will move towards it. If you change your behavior, you will move towards the new translated weight. The translation appears to be a combination of genetics and perhaps past experience (she claims loss-and-regain cycles increase the set point. I’ve read that a lot of places, but at this point I neither trust her nor have the heart to investigate).
So how do my current views compare to those I held before reading HAES?
Exercise- still good for you.
Human diversity- still vast.
Impervious of weight to diet and exercise- depends a lot on what you mean. I will never look like Keira Knightley, but I will probably lose fat if I exercise more. Which I have just started to do after ceasing for a very long time because I was recovering from surgery, and will pause again when I have my next surgery, because the health harms outweighed the benefits. Fat is a proxy for health, but not the only measure of it.
Large amounts of fat are quite bad for you, but it’s unclear where that effect kicks in. The American aesthetic ideal is much lower that the healthy weight cut off, and may be actively unhealthy. In the normal range, diet and exercise have bigger health impacts than fat.
Our food supply is definitely fucked.
Fat people still don’t deserve to be shamed, especially under the guise of for their health. First because no one deserves to be shamed, but especially because shame is super bad for your health. It is intrinsically bad and it keeps people from seeking medical care, for both things related and unrelated to their fat. Stop doing it. People owe you neither their health nor their attractiveness.
*Weirdly, in my case it appears to be weight. I’ve had a shockingly consistent weight despite large changes in activity level and muscle mass.