About the trait to store more energy - i.e. more fat - in case of famine. It just occurs to me that this is invariably associated with the ability to use that stored energy during famine. Case in point, fasting. It will allow more ketogenesis and more ketones, which means there's more fat coming out of fat tissue, and the only reason this happens is there's less insulin.

Just saying. We can't talk about one without talking about the other. The two go hand in hand.

Now about low-carb and how it fits. Relative to SAD, low-carb causes insulin to drop. Well, that's pretty much the same story with famine, ya? So here's the logic here. If LC is about the same as famine from a physiological point of view, but with food so it's not actually famine, then we get the best of both. In effect, when we eat LC, we are fasting.

Makes no sense, right? Wrong. We fast in-between meals. That's when fat is lost, when weight is lost. Not when we eat. We gain weight when we eat. OK, so I'm just stating the obvious but that's how this problem is explained. So, relative to LC, SAD prevents this in-between fasting. In effect, it's like we're always eating.

Now back to this trait to store more energy in case of famine. Well, if eat the same, but there's barely any in-between meal fasting cuz insulin stays too high, it's effectively the same as if we were storing more energy. It's in the math. If the minus (in-between meals) is smaller, it's the same as a bigger plus (during the meal). So basically we don't need to invoke a genetic trait to explain, regardless of whether this trait actually exists. If it does exist, then SAD certainly activates it beyond normalcy.

This applies to my former eating habits of grazing, which has been very hard to break. I was not eating a lot more than I eat now, but I was constantly eating with very little fasting in-between. My insulin levels never got a chance to go down. And I stored lots of energy! Many diabetics are told to eat more small meals throughout the day and for me, that is just wrong. It's what got me here in the first place.