To be fair, the yanks don't even need to change their diets to loose weight .... they just need to eradicate those stupid portion sizes.
A steak doesn't mean half the cow on your plate, a sandwich doesn't mean putting everything you can find in the shop (including the kitchen sink, if you could !) in between two slices of bread ... etc..etc..etc
Its simply grotesque.
Also, soda servings in excess of 20oz (already huge!) to begin with, regardless of refills.
I agree that reducing bad food and portion control is the answer, but it's very hard to drive behavioral change in people. And the health industry has done a "good" job of creating medication to enable bad lifestyles i.e. metformin for Type2 Diabetes, other drugs to manage cholesterol, etc.
GP's point is that calories coming from a "healthy" source doesn't mean they don't count. Drenching one's salad in olive oil rather than canola oil won't help someone lose weight, nor will switching from soda to a fruit juice with the same amount of sugar in it (ancillary benefits of e.g. vitamins notwithstanding)
Not exactly, just because you've replaced those calories doesn't mean that your body didn't gain muscle mass which itself requires calories just for your body to maintain. This leads to a higher basal metabolic rate, which ends up burning calories even while you rest.
A 500 calorie workout might only be 400 extra over spending that time sitting on that couch. Similarly extra muscle on it’s own takes energy but fat also burns energy so even modest weight loss balances that out.
(Have a look at people who are 80+ and fit. Most of them are slim. You don't see a lot of bulked up old people)
Old people aren't super muscular because you need high levels of testosterone to support musculature, and it naturally declines with age and particularly tanks when you are elderly.
I've seen that myself, a long bike ride will often be followed by an evening on the sofa.
No, the problem is and will remain dietary in nature. Americans could stop all exercise across the board, change their diets, and lose massive amounts of weight trivially, just by cutting out a few common items that nearly all obese Americans over-consume. I've yet to meet an obese American whose diet I couldn't trivially radically alter by just removing a few particularly horrible things (eg sugary drinks, ice cream, pasta/pizza, high sugar snack goods). People think they have to change everything about what they eat and go to the gym five times per week to drop weight, and that's entirely false, all they have to do is eliminate or dramatically reduce the couple worst items in their diet and that's usually enough (it's rare that there are dozens of villains in their diet that matter, it's almost always just a few items that are doing 3/4+ of the damage).