HAES pre-check

I’ve been meaning to do a “science of fat and health and food” series for a while now, but have never quite gotten it together. There’s too much stuff I remember reading in some blog years ago but can no longer find.  The library has finally delivered Health at Every Size to me (just in time for Thanksgiving), and I’m hoping to use that as both a serious source and a jumping off point for other research I want to do.  In the spirit of inquiry, here are my basic beliefs, as cobbled together from an undergrad biology degree, personal experience, things people said on the internet, and scientific studies I read the abstracts of.  When possible I’ve included a citation but mostly this is just stuff from my brain.

1. Some diets are lead to a better functioning body than others.
   1. The healthiest diets supply all necessary trace nutrients, including ones we haven’t identified as necessary yet.
   2. Protein, fat (of multiple kinds) and carbohydrates are all necessary for proper functioning.  Right now a lot of people are pretty sure that you should minimize carbs and especially sugars, but 20 years ago they were equally sure fat was evil, so I’m unconvinced even though their numbers look very shiny.
2. Exercise is super good for you right up until the point it is super damaging.
3. Despite our astonishing lack of genetic diversity, humans have a pretty wide range of how they react to identical food and exercise inputs.  Additionally, the same person can react differently to things over time.
   1. For example, people’s beliefs about the deliciousness of the milkshake they are about to receive affects ghrelin production, which definitely affects satiety and probably affects nutrient and calorie absorption.
   2. Medication can do the same.  Cortisol makes you gain weight. Several psychiatric medications lead to severe weight gain.  Hormonal birth control definitely used to make you gain weight. Many scientists claim the newer drugs haven’t been shown to do so, but my feeling is that “baby chemicals lead to weight gain” is the default assumption and the burden on them is to prove it doesn’t.
   3. Past deprivation, including in utero, can decrease basal metabolic level, or make it more likely to decrease in the face of further calorie deficits.
4. At the same time, people are remarkably resilient to environmental changes.  A given person can eat a wide range of calories and stay at the same weight.  No one understands why.
5. So while calories in/calories out is literally true, in the sense that everyone is taking in and using calories, it’s not useful, because so many things affect intake and output.
6. It is possible to have an excellent diet and exercise routine and still be fat.
7. But any given person will probably be fatter the worse their diet and exercise.
8. When you tease these out, fat is mostly a symptom of things that lead to bad health, not a cause of bad health.  Extreme amounts of fat are hard on the joints and heart.  But all evidence says (good diet, good exercise, 40% body fat) > (bad diet, no exercise, 20% body fat)
9. Nonetheless, the general and medical public alike seem extremely fixated on fat, and this is hurting fat people.
10. Shame around fat seems to contribute to both fat and the negative health outcomes associated with being fat.  Shaming fat people for the health is right up there with rescuing prostitutes by arresting them.
11. To the extent fat itself affects health, the ideal body fat % from a health perspective is much higher than the ideal body fat % from an American aesthetic perspective.
12. Lab animals are fatter than they were a generation ago despite provably identical conditions.  This has got to mean something about our food, and it’s probably not good.
13. It is possible to be both fat and undernourished.  Most poor Americans are.
14. Your body needs calories to run.  Faced with a calorie deficit, your body may choose to cut programs (like the immune system, or thinking) rather than dip into savings (stored fat).  This means that maintaining even an “unhealthy” weight may be the healthiest choice a person can make.