Makes more sense, but I think you are siding with genetics to the exclusion of environment, behavior, and how body signals can change over time.
Hopefully I'm not 'siding' with anything... I'm a big advocate of the phrase 'obesigenic environment' and often the first to point out that we're not genetically different than our grandparents, who were demonstrably thinner. The environment changed, and the genes interact differently.
I was probably also lumping 'body signals change over time' into the 'partly genetics' bucket, since that will vary from individual to individual. Specifically, endocrine management of appetite.
Middle-age weight gain is most likely due to the decline in energy expenditure due to lower activity and muscle mass, not genetics. Many people report feeling full and hungry differently when they have lost weight than when they were obese. And so on.
Yep. Lots of factors interacting, but I would say that our genetics is the platform upon which we experience a decision landscape. Extracting 'blame' and 'accountability' gets complicated when we see how, for example, identical twins separated at birth are almost always within 1.0 BMI decades later.
Here in 2016 we need new skills that our grandparents didn't have, they weren't battling sophisticated marketing departments pushing calories. We need to make different decisions, and in an environment where our genes have much more degrees of freedom to fulfil their programming, we need to be aware of them if we want to 'fight' them.
Here's an example from last month. Marketing departments have learned that there are two times of year where there's an exaggerated opportunity to create bad eating habits: January (because of New Years' Resolutions) and September (because families are under a lot of time stress with school starting). So, this is when you can expect those A&W, Subway, McDonald's, KFC, and Church's Fried Chicken coupons to start fluttering in the mail slot.
There's a psychological principle nicknamed the "what the hell effect" (Janet Polivy's work, eg: [
Getting a bigger slice of the pie. Effects on eating and emotion in restrained and unrestrained eaters]). Basically, if you break your commitment to yourself ("I won't drink this year") then for some reason we decide the whole deal is shot, and our discipline is weakened. If I have one drink, I might as well get hammered. If I get takeout one night this month, I might as well do it every night. They want to break our resolve as soon as possible after these typical commitment start dates, it increases sales until the next cultural timeframe commitment start date. (at which point they do it again)
ETA: I forgot to make my point about our grandparents and coupons. Our grandparents would say use the coupons, because cheap food was rare. We should
throw away the coupons, because food is so cheap now we don't need to risk obesity to save nickels. Our grandparents said "Always finish your dinner, there's people starving in Japan" - we should
not finish our dinner, if we're not hungry. Somebody put too much food on the plate, use smaller portions next time. If you don't like waste, save the leftovers for lunch - don't shove it down.