This week I did something I have not been tempted to do for more than 40 years: I ventured through the doors of a McDonald's.
With much of the western world about to plunge into the most intensive food fest of the year, with immeasurable harm being done to our health and our bank balances, I decided it was important to see first hand what contribution the world's hugest purveyor of restaurant meals was making to this season of serious overindulgence.
This after all is the company that put "fast" into the concept of "fast food", and capitalised on the US industrial farm system to make a US$1 cheeseburger possible.
More than almost any other company, its golden arches have come to be the single strongest global symbol of US influence (it had a 16-year head start on Starbucks).
My disdain for this dubious ambassador of US dietary habits has not always been so strong. I recall the excitement and curiosity I felt in 1976 when I first saw those golden arches appear over the horizon as I was being driven by a proud Canadian friend into Montreal.
It seemed so much to be a symbol of a rich and advanced nation – though if I remember correctly, my friend was much more excited about the thick milkshakes than the burgers.
That was fine by me, because I was already vegetarian, and had no particular yearning for Big Macs. I had to admit the milkshakes were a revelation compared with the insipid offerings I had experienced through teenage years in the UK.
Since that time four decades ago, my indifference towards McDonald's has only been matched by its remarkable global growth.
The group nowadays has annual sales worth US$25 billion ($36b), and feeds around 70 million people daily through a remarkable total of 37,000 outlets worldwide.
For so many years I had retained a snooty disdain for a group.
Being a vegetarian, there was nothing in those offerings to tempt or corrupt me. So why now walk through their doors?
Mainly because I wanted to see if my prejudices remained well-founded. But also in part because I was curious about the repositioning now in progress to breath fresh life into the group, and to reverse a slump in market share that in 2015 took the scalp of its then chief executive.
There was also a quirky inquisitiveness to see how the new chief executive, British-born Steve Easterbrook, might succeed in ways his American predecessor could not.
Interestingly, he appears to be immune to any angst about the "junk food" reputation that had made McDonald's the stalking horse of all those governments, doctors and community groups raising alarms about poor nutrition, poor health, and rising obesity levels.
No longer is the group putting clementines into Happy Meals, or slipping avocado slices into chicken sandwiches.
To be fair, McDonald's are not doing nothing about these mounting public concerns. They promise that they will in future only use chicken and meat that has not been pumped with antibiotics, and they are cutting corn syrup from their buns. And they promise to use freshly cracked eggs in their Egg McMuffins.
But research has told them that many consumers still above all else want cheap, and after 10 years of recession following the US financial markets crash, that research may be right.
Research has told them that many consumers still above all else want cheap, and after 10 years of recession following the US financial markets crash, that research may be right.
In the words of Larry Light, McDonald's former chief marketing officer: "Instead of trying to come up with new kale and bean salads, (Steve Easterbrook decided to) fix the familiar. Fast food is not in decline."
With a "modern progressive" mantra, his marketers say he is focusing on "day-to-day basics", like improving the quality of its food ingredients while at the same time still selling McDonald's as a place to eat cheaply.
So far he is ignoring the pressure to respond to the obesity and nutritional crises for which McDonald's has in the past taken much blame.
He may yet pay a price for this as the global obesity crisis becomes steadily clearer and more severe. But on the other hand, he may not, since scientific argument about the causes of the obesity crisis remains robust, and McDonald's can't be the only people to blame.
As Professor Tim Spector says in his impressive book The Diet Myth: "Trying to work out what is good or bad for us in our own diets is increasingly difficult … confusing and conflicting messages are everywhere."
For those who claim the source of all dietary evil is fats, he points to the Cretans in Greece who today are among the world's most prolific consumers of fat, but among the healthiest and longest-lived. For those who blame sugar, he points out that Cubans today eat twice as much sugar as Americans, but are much healthier.
Pointing to the plethora of diets that over the decades have achieved nothing – and the 30,000 books on dieting – he muses that if we took them all seriously, "there would be nothing left to eat except lettuce".
"Obesity is still a massively neglected area of medicine, with little funding, no speciality training and no common voice with which to try to combat the billion-pound marketing budgets of the food companies."
So Easterbrook and McDonald's are not off the hook. Tim Spector's lifetime conclusion is that "diversity is the key", and that the Mediterranean diet that mixes grains, legumes, vegetables, nuts, fruits, lots of olive oil and fish and unpasteurised dairy, with a smattering of red meat and "moderate" amounts of red wine, appears best for our long-term health.
That means to me that the US$1 cheeseburger or the Quarter Pounder remain irredeemable, and that if we want to stay healthy, we should still be steering a wide berth around places like McDonald's – not just around the Christmas festivities, but year-round.
It has taken me 40 years to revisit, and I can happily wait another 40 years before I test them again. Not that Steve Easterbrook cares. With 70 million people every day who disagree with me, who cares what I think?