I'm struggling a bit with my own waistline and exercise still. I'm fortunate to have had decent habits from childhood and got through my 20s and early 30s on that, but at 40, it is taking work, and the past year of being around the house with a well stocked kitchen (and we did stock up when things looked ominous in Feb 2020 so there's been more out visible) and all my external habits and motivation stripped away, and I just have no internal drive left. I'm bored of my runs because for so long that's all I was left with. Classes have been on/ off so any progress keeps being lost. Being at home with the extra catering for a ravenous family and their incompatible likes and dislikes and no fresh inspiration.
I'm in a good position and have knowledge and it's still hard to manage!
I think the daily mile in schools is a great initiative. Quick, free, accessible, 10 mins non-competitive running/ walking.
Parkrun has also become a great force for public health. Free, sociable, local, fresh air, not hemmed into commitments. It's worked better than gym prescriptions with longer lasting commitment.
The change 4 life has done well on branding, but the advice is not well balanced. A lot of it works on the assumption that everyone is totally sedentary, swigging 2l bottles of coke all day. I tend to bin the packs that the DCs come home with because we already do more than it suggests. Small steps like adding drinks of water, add a portion of veg, have a movement burst during long periods of sitting are more achievable rather than recomnending diet drinks) Michael Mosely's just done something on this kind of theme about small habits to add in although I haven't seen the full details. A Mr Motivator type slot of gentle exercise that can be done as you are through lifestyle TV (GMTV, This Morning, Loose Women, The One Show)
I have really noticed a change open in many of my DCs' peers. Those who were actively into sport have picked it up and are largely unchanged. Those that were more sedentary and getting heavier anyway have really accelerated. It's not a moral judgement, but it does physically affect hormones and development and is a hard template in early life to reset. As a child who loathed PE at school it is delicate to address activity without stigmatising (I was fortunate to enjoy dance outside school which led to doing aerobics then other exercise in adulthood) DS1 has lots of interventions for literacy, but the same strategy for PE would be like a lead balloon with many families, so it needs to be more active time for all. Choice helps and I found in y11 that when we could select/ drop activities, that helped. I enjoyed our new gym, but even having the choice of doing hockey and never touching a much hated netball again was a bit more empowering.
Workplaces need more defined breaks. Get people away from the desk. I used to take advantage of the school canteen, partly because it was a decent value meal and I'm not a sandwich lover, but because in a snug 30 min window, it got me moving for about 10 min, often through outside space. Even promoting 5min desk based movements would be good for posture, energy and productivity.
Generally better walking and cycling spaces would make active transport more viable.
Our risk-averse culture often doesn't help either.
The information is out there, but it is making measures accessible and adjusting culture that's the challenge.