@Eff Your misunderstanding two fundamental points. First is that yes, everyone is born with a genetic predisposition to a particular weight. Even if they are raised with the exact same diet, this will not guarantee that two people will have the same body type or weight. What you misunderstand is that "genetic" does not mean "fixed", and "predisposed" does not mean "predestined". This predisposition does not mean that weight loss cannot be maintained indefinitely.

@Eff What it does mean is that, if you try to change the symptom (weight) without addressing the underlying cause (the body's inclination to be a particular weight) you'll invariably fail. Traditional diets don't work because, by focusing on the symptom, they drive change in the underlying cause which works against the desired result. There are a very few people who can ignore those cues and traditional diets work for them, but they are a small minority.

@Eff The majority of people need to address the underlying cause to have any reasonable chance of long term success. Which leads to the second thing you're misunderstanding: the natural processes of your body are not a character flaw.

@Eff Hunger and thirst are (behind the need for air) about the strongest biological impulses we have, and for good reason. Your body is a dynamic system, and your conscious desires only run a very small part of it - which is good, we're so complex that managing our autonomous systems would be unmanageable if we had to pay attention to them all. These systems are geared towards keeping us alive - breathing, sleeping, and (unsurprisingly) not starving to death.

@Eff The links describe our current understanding of how to influence weight - eat healthy but relatively boring food to cut down on the extra signals that keep a person eating past the point of biological need, and stop when you are full. Doing that fools your body into thinking it doesn't need to pack on the extra weight in a similar fashion that traditional dieting fools the body into thinking it's in a famine and needs to save what it can as fat.

@Eff Granted, this is our current understanding and our bodies are incredibly complex and dynamic systems, so a better way may be out there waiting to be discovered. We have, however, moved past the simplistic idea that simply cutting calories is sufficient to drive long term weight goals.

@Crowley That's the trick though - the background processes of the brain drive those rewards, and adjust them accordingly. I can't sit down and demolish twelve boxes of Peeps any more - not because I don't want to, but simply because they don't taste as good as they used to. My body has adjusted the reward schedule for Peeps because I don't need as many calories as I did when I was swimming a couple of hours a day as I was at the time.

@Crowley On the whole you're correct about hunger being driven by what the body needs. The situation is complicated by two factors. The first is that the body doesn't always know what it needs. Traditional diets convince the body that it's in a famine, so it reacts in ways that work against weight targets because it's preparing you to survive long term lack of food.

@Crowley The second factor is on that @Eff misses as well: food has been commercialized and has been designed to be intrinsically rewarding to eat. Weight comparisons to 200 years ago aren't valid because the incentives to eat are much different than they were even 100 years ago. This is one of the reasons that the current weight loss advice includes eating relatively boring foods.

@Crowley It makes it easier to pay attention to the signals your body is giving about being full if the other incentives to continue to eat are removed. Essentially, each person has a range of caloric intake that's healthy for them, a fairly small range at the bottom of that healthy range which drives safe and maintainable weight loss, and a fairly small range at the top of that healthy range which drives safe and maintainable weight gain.

@Crowley Traditional diets focus on powering though excessive cuts to calories, which triggers the body's response to starvation. Eating way more calories than your body is willing to accept triggers nausea, vomiting, stomach pain, etc. The key isn't willpower, the key is listening to your body and understanding the mechanics so you don't trigger these excessive responses.

@Morgen No, I don't miss anything. I know that food has been commercialized in a completely different way today. It is you, from the beginning, wrote stuff like "it leads invariably to long term weight gain rather than sustainable weight loss" and "we don't yet have a consistent, universal, and effective path to being thin". Those things are just wrong. You've written things that ARE absolute and deterministic. Now you're just backtracking. Anyway, I think I'm out of this conversation.

@Eff Perhaps "invariably" was the wrong word, however it's undeniable that traditional diets lead to long term weight gain for everyone but a small enough population that rounding is a larger source of variance. "we don't yet have a consistent, universal, and effective path to being thin" is the truth because "eat X not Y" doesn't work for everyone, "cut X calories" doesn't work for everyone, and what I've described as the current best practices for weight management doesn't work for everyone.

@Eff I'd assumed you'd missed that because I couldn't see any other reason why you'd compare weight statistics now with weight statistics from 200 years ago. The conditions are so very different that, aside from describing long term trends, the comparison isn't meaningful in terms of deriving weight management solutions.

@Morgen The reason why I brought up 200-year-old peoples is because it's a slam dunk easy way to demonstrate that there is a way to stay non-overweight. Simply eat the diet they had, that's it, you're basically guaranteed to not be overweight. Now, I don't suggest people actually do that in practice. Here is a tip for anyone for wants to never become overweight: from the day you're born, never eat anything with processed sugar. That doesn't guarantee anything, but it's certainly a good start.

@Morgen Everything you're describing still boils down to the psychological needs of cravings. The physiological side remains as it is: you consume more calories that you expend and you gain weight, you consume less and you lose it.

@Morgen I've never heard of this "default weight" concept. It sounds just like an excuse, but I can see how it can be applied: your cravings drive you to eat what amounts to X calories per day. X calories was at first more than you spent, thus driving your weight up.

As your weight goes up your calorie consumption (how many calories you need to maintain your current weight) also goes up, and eating the same as before no longer drives your weight up. This would be the "default weight" you mentioned, but notice how it's based on your current craving-driven eating habits, i.e. entirely psychological.

Slowly, your now elevated calorie consumption as well as the fact you're now more accustomed to eating a ton of stuff (both psychologically as well as your stomatch being able to store more food) would drive your food cravings up, restarting the whole process. This would be your "default weight shifting".

Your wife losing weight by eating healthy would just be her being more in control of her cravings and just accustomed to eating less and less calorie-filled food. Dropping sugars, while at first hard as F***, soon makes most of the cravings go away after peaking because hey, sugar truly is addicting.

But note how all of this is strictly psychological. Be careful to attributing these effects to genetics or faux concepts like a "default body weight" since that only serves to make these harder to deal with. But please don't feel attacked or looked down upon since a lot of people struggle with this; cravings, specially sugar-based cravings, are a hell to get rid of.

To lose weight one simply must just drop the calorie consumption. While beseiged by these cravings it becomes extremely hard, so these should be dealt with before trying to count calories. But don't make stuff up, don't feed your brain more reasons to why your weight going up can't be helped. And specially do NOT spread such misinformation.

If you decide your current weight is fine and you don't desire to lose weight then by all means, don't change a thing. But read what I wrote carefully; don't do it thinking it's something you physically can't change. Accept your eating habits by knowing that it's your mind the one that's making it hard. And again, it makes it hard for all of us.

I applaud you for keeping your cool while having other people challenge your lifestyle. I hope that same cool can be used to reassess your current situation and wish you luck, as long as you don't decide to feed on the excuses. They're dangerous. Many people became very unhealthy by giving in to them.