Germans are far more blunt than the British and many think nothing of telling you that you have got fat, same as in many Eastern Asian countries. Over here, people pussyfoot around the issue too much.
While it's a big yes to outdoor opportunities (including decent cycle routes - I miss those!), it is absolutely not true that Germans eat less processed foods - the processed meats for breakfasts and inners alone are something else, and so are a few very popular regional dishes (Eisbein, currywurst, Berliner - just to name a few).
What strikes me as very different is the actual taste of food - British fresh food can often be very bland. Compare that to the taste of fresh cucumbers, apples, tomatoes etc. in Germany and you'll be astonished at the difference.
There was also a big drive to home-grow food on balconies in flats (we used to get tomatoes, courgettes and marrows on a regular basis) or fruit in larger gardens.
Another big difference is the culture of common sense.
In Britain, there are signs by every lake near here forbidding you to swim because even one child getting in danger is seen as a minor catastrophe, as opposed to German lakes, where it's generally up to you to make sure you're safe.
Woods are far less often fenced off, so exploring them is much more enjoyable.
An indoor ice rink company near here has recently decided to mandate helmets for all children after the tragic accident of one child, after decades of successful, accident-free business. My children now refuse to go, where before, they loved ice skating.
And when I was young it was perfectly fine for me to walk to and from school by myself aged 6 (latchkey children are a very common thing) - my children here have to wait until they hit 10 or 11 before the threat of SS is lifted.
So yes, Brits are far more sheltered and therefore far less active.
As for haircare and skin, yes, the great outdoors helps, but Germans also use far fewer products and damage their hair less as a result. It used to be common for people to walk in the rain (good for your hair no end), dyes are generally less invasive and there is a huge market for organic, vegan and sulfate-free products.
People in this country are astonished that I only buy blue Nivea, but my skin looks 10 years younger as a result of just going for a very basic cream rather than 10 essential oils and perfumes.