I don't know of many people who think drinking orange juice is much different than any other sugary drink.
I guess we hang with different crowds, then (no climbing puns intended).
I agree with your comments on the BBC programs regarding weight loss (and the U.S. ones as well). I also think that most "diets" should be avoided. I use the term diet however just to refer to what any of us eat.
Yes, the "diet" term can have several confusing non-equivalent meanings. When it comes to typical long-term eating, I try to refer to that more as "lifestyle".
People who are overweight don't have a caloric deficit so your ideas regarding junk food (high quality or otherwise) aren't that relevant. Also, I'm not sure "high quality" junk food even makes sense. At that point it's just food. Chocolate is just "food" with a high enough cacao content and a low enough portion size.
By high-quality junk food, I simply mean that it tastes amazing and delivers top satiating value for every calorie, hopefully leading to less calories consumed in total. From a nutritional standpoint I see junk food as simply a mix of carbs and fat with possibly small traces of protein, which may or may not be of use depending on what else you're eating and what kinds of activities you're engaged in. If I'm short on my caloric targets for the day but have already seen to all my other nutritional targets, carbs and fat are all I really need at that point and I may as well enjoy something which feels delicious and rewarding rather than something bland.
I don't think any long term way of eating can be based largely on discipline although you do seem to be arguing both sides of the coin. You say that discipline can't be the answer and then blame people for not having the discipline to lift weights for 2 hours a day.
No one needs to work out 2 hours a day to lose weight. I've lost massive amounts of weight in the past through caloric restriction alone, but didn't find it very sustainable long-term with all the stresses I was feeling in life and my undying love for tasty food. Granted I never got anywhere near back to where I was as an obese kid, but I could never hold even 15% bodyfat for more than a few months or a year before just losing control and eating more of everything like before, including far too much of the "healthy" stuff. To be fair, I was going through some extremely rough emotional times back then, and still am to a degree.
It's been much better for me this time around. Even when exercising seriously and consistently over the last 4 years, there have been plenty of days when I restricted my calories to a level that would make even sedentary people lose body fat, especially in the first 2 years when I was only running less than 1 hour per week, but I have far more motivation and discipline now because I've got actual goals in mind, and a physique that I'm actually proud of for once in my life that I find worthy of maintaining and improving regardless of what I'm doing. Losing weight on its own just turns me into an average guy, whereas losing weight and building muscle turns me into someone people actually stop to look at and want to emulate, which gives me far greater incentive to keep at it.
When did I say discipline wasn't the answer? Discipline is entirely 100% the answer in my opinion, but one needs to be well-informed to discipline themselves, and the commonly available information isn't sufficient or accurate enough to meet that need, with all the pseudoscientific background noise drowning out the signal. We seem to be agreed that in theory, junk food can be incorporated into a successful weight loss diet even for a sedentary person via net calorie restriction, and I've been doing it for 4 years even when I was starting out on relatively low amounts of cardio, but discipline is the key. In my opinion it's been far easier to maintain discipline when I allowed myself to indulge in modest amounts of junk on a regular basis, but if someone finds it easier to discipline themselves by shunning junk foods altogether, no need to fix what ain't broken. I simply believe that most people will find it far easier to maintain a lifestyle long-term that still allows them to regularly indulge their deepest cravings while still keeping everything in balance, and you seem to think those cravings will disappear over time if you ignore them long enough. I haven't seen evidence of many people suddenly eschewing junk and successfully forgetting about it for the rest of their lives, whereas I've seen lots of formerly-fat people succeeding with the former approach.
I've known bodybuilders who insisted you'll never look like them if you eat so much as a teaspoon of sugar per day unless you're on drugs, and others who will eat anything you put in front of them as long as they can afford the calories, both getting comparable long-term results even well into their 50's. Discipline comes in many forms and I think it only makes things harder when you try to limit your available options.
I think you need enough discipline to change your habits to healthier eating and after that it should stand on its own.
I would agree, if your definition of "healthier" simply focused on the total nutrient intake and not the particular form of the various carbs, proteins and fats providing all those nutrients.
Fighters, weight lifters, those that you describe as skinny or fat and picked on earlier in life are usually short rather than skinny or fat (and were in fact picked on).
Shortness is another reason many fitness guys were picked on and motivated to change in youth, but you'll hear plenty of stories from fighters, lifters and competitive bodybuilders about being picked on horribly for excess weight or thinness too. With hard work fat kids can get fit and sexy too, it's a proven fact.
Fat isn't "bad" but processed foods (high in fat or otherwise) are not the best things to be eating. There's nothing magical to just preparing your own food and eating non-processed food as much as possible while limited sugar and excess carbs.
Well here's the whole gist of it: I advocate for a lifestyle which doesn't require the discipline of a Viking in order to achieve it. You seem to be eliminating an entire middle ground here; It sounds like you're saying "avoid nearly all ___ and ___ or you're virtually guaranteed to be fat for life," which no science has yet reliably established to my knowledge even when restricting studies to specific communities or ethnicities. And yes, I would argue that well over 50% of the population if not much, much, much higher would find that it requires "inhuman" discipline to act as if they weren't completely surrounded by an abundance of processed carbs and fat. I'm advocating that one should indulge cravings in modest quantities so as to avoid even bigger cravings and ultimately a complete dietary rebound.
As for home cooking, if you have time for it then great, I personally love to cook and bake from scratch when I can. I myself am a believer that if you can prepare something leaner and more nutritious at home that delivers just as much or more taste as something store-bought which is stuffed with fat and sugar to hide the preservatives and lack of quality and freshness, then you should totally go for it. I already mentioned either here or in the related Human Science discussion we were having that I now avoid restaurant bacon and sausages, because they tend to have disgustingly low protein-to-fat ratios without any noticeable benefits to taste and satiety. On the other hand, if you don't have time or the skills to cook at home, it's not going to kill you to eat out and indulge in a few sweets and fats here and there, as long as the macronutrient totals still add up to the right amounts.