But diets have always been high in carbs anyone over 50/60 will have been bought up on them. Bread potatoes and root vegetables were the main part of a meal also later pasta when it became fashionable and everything with sugar. Just like overweight people they will not all develop diabetes and the majority who have it will still be eating that way because they have never heard of low carb and probably would not do it if they had. .Low carb among diabetics is a minority thing
And oddly, that's an age group where T2 diabetes has been increasing. But correlation isn't necessarily causation, and there are probably other factors. So I'm 49 and remember as a kid, breakfast was toast and Marmite, lunch often skipped and dinner being chops, mince or some variation on meat & veg. Potatoes were pretty common, although usually boiled or mashed, chips were more of a treat and pasta was spaghetti or mac & cheese. And I also remember that dessert was for Sunday dinners or special occasions.
But I also remember walking to school, playing school and club sports, being out playing from dawn to dusk, having a paper round and thinking little of a 20 mile round trip cycling to the coast so I could go swimming with my mates. So I was also pretty active, unlike a lot of kids growing up today.
And I also remember as a kid, meals were mostly cooked from basic ingredients, not from cans, jars or ready meals. As I got older and started fending for myself, I still liked to cook, but work and long commutes meant eating a lot more junk food and ready meals. Now I can't work, I have the time to go back to basics and cook & eat properly again.
So I think there have been big social changes, ie less active lifestyles, a lot more convenience foods, and probably more stress from working and commuting. And I think there are vicious circles within those, ie stressed or tired from work, can't be bothered or too tired to cook properly, so grab some microwaveable lasagnes and some crisps. Breaking those cycles is going to be hard, especially if kids aren't taught or shown how to cook and expect treats or convenience foods. Then they'll go to work, grab lunch from a vending machine or supermarket sandwich/crisps/soft drink meal deal and microwave something in the evening. Or order a take out.
So with our modern living, I don't think it's suprising that there's an obesity epidemic..