Restaurant food politics

Many years ago, I spent a decade as a chef.  I moved every five months, on average, worked up to 120 hours a week, learned what I needed to learn and explored the vast (3 million unskilled jobs lost to the smoking ban in the UK) catering industry.
I had started as a waitress, earning more between tips and excessive hours than the owner of the restaurant I worked in, and quickly figured out that whilst the chefs had the scars, they also got to go home and earned more hourly than I did.
Anyway, what I learned, from working across the industry, was a lot of unexpected stuff about food politics.
You tend to get a lot fatter eating in a cheaper restaurant, because the food in cheaper restaurants consists of a lot more filler foods, such as cereals, potatoes, flour etc.  Deep frying is an excellent way of presenting such foods, and is crunchy, hot and tasty which is all a casual visitor really wants.  In one struggling establishment, I succeeded in making a burger so addictive that people were coming back three times a day for the same meal.  I achieved this by combining piquancy with salt and sugar, an apparently irresistible and satisfying combination.
In more expensive restaurants, where foods are very high quality, often take hours for a badly paid team to prepare, with smaller portions, you tend to shed this excess weight extremely quickly due to your workload.  One of my exs was voted the best chef in Western Europe (once upon a time), and he had me working from 7am until 3am the following morning, seven days a week.  Food is a very unrewarding art form at this level, but the challenge of creating a dish incorporating sweet, savoury, bitter, digestive, levels of crunchy, colour, flavour and texture is a fun creative exercise, not to mention the knowledge and skill acquirement of getting to work with more expensive materials.
If you then transfer these skills back to a cheaper restaurant, things get a lot more interesting.  I caused quite a stir with my venison and chocolate sausages with prune chutney once upon a time.  Sadly, the ex got quite jealous at that point.
The point for you in terms of your health is the idea that potatoes, flour, deep frying, the sugar and salt combination, sweet and heavy puddings are now considered filler foods for poorer people. This means that someone, somewhere makes a good margin of profit from such foods.  Shooting for quality in your diet means avoiding such foods in favour of fresh, well prepared, non processed food.
Likewise eating in Marrakech was fascinating.  Moroccans have the benefit of a strong export trade in fruit and vegetables, meaning that the bruised seconds available make eating a lot of these very simple, as long as you have plenty of bottled water to wash them with.  Meat is not always refrigerated, hence the very well cooked tagines they are famous for, and sugary mint tea is the norm. I was curious about this very warming and very cooked diet when I was there, and found out quite quickly that eating raw is something that becomes more difficult without a reliable clean water supply.  Hence the well cooked traditional dishes and the sugary tea.  Sometimes it is all you can keep down.
Scotland has a strong export trade in quality meat and fish, meaning that we have pies, haggis and sausages to use up our own ‘bruised seconds.’  Such is the influence of commerce.  Feed the population on the bits you don’t sell, and pretty soon you have a traditional diet full of off-cuts.
In conclusion, food is as political as fashion, and your diet, like your clothing, should reflect you and not what the whims of time dictate.  Eat as well as you can afford, and avoid filler foods as much as you can, because if it has been used as something to fill the stomachs of the poor, then you can bet it shortens your life.