Think before you carve
Can I apologise right now if the content of this blog dampens your Christmas spirit? It is about something many of us believe we should do, but very few of us actually get round to doing.
It was certainly the hardest thing I did during my "year of living ethically" for the BBC.
But Adolf Hitler managed it and so did Linda McCartney. Indeed, the government's former chief economist says we should all do it.
Are you there yet?
Yes, I am talking about giving up meat. Or, in my case, giving up all animal products.
But I should warn you we started our exploration of the ethics of what we eat with a lustrous Norfolk Black turkey chick we named Ned.
We watched him grow into a magnificent one-and-a-half stone stag... and then came Christmas.
Viewers with a sentimental nature should NOT watch this film.
I said at the time that I regretted not killing Ned.
"An ethical man should be able to stomach dispatching his own supper or should decline to dine upon it, shouldn't he?" I wrote.
And I am sure lots of us carnivores would be a lot less keen on our mixed grills if we had to look all the animals that go into them in the eye before they were served up on our plates.
But this blog isn't about sending you on a vegan guilt-trip - though if that's what you want, you can learn more about the mechanics of turkey slaughter here.
Neither is this blog about the bizarre animal ingredients I discovered might be lurking in even the most innocent-seeming foods - bread anyone?
It is also not about the incredible health benefits I experienced from my brief flirtation with ethical eating - I shed 2kg in 31 days and saw my cholesterol level plummet from 5.6 mmol/L (rather high) to just 3.4 mmol/L (very low for a man of my age).
Nor is it about how the food we eat is destroying the planet. Everyone knows that now - though, if you will allow me a little boast - we in the Ethical Man team pretty much got their first.
So what is this blog about?
It is about another aspect of the food we eat - the threat of an impending food crisis.
There was a hint of what could be to come back in 2007-8 when world food prices soared leading to food riots around the world.
Well, don't imagine that the worldwide depression has got us off the hook. Food prices have risen dramatically this year even as economic activity has fallen.
According to the UN Food and Agriculture Organisation (FAO) a billion people on earth will go hungry this year - one in six of the world's population. That's a thought that will haunt you as you sit down to enjoy your Christmas dinner isn't it?
But, lets be clear about this, there is no shortage of food in the world. Agricultural output is pretty near its historic high. So why are so many people going hungry?
The problem is that, increasingly, we don't actually eat the food we grow. Some is converted into bio-fuels - and rising oil prices makes that more profitable - but even more is used to fatten up the animals so many of us eat.
There has been a huge increase in meat consumption around the world in recent years. That trend should be a cause for celebration because it reflects that fact that people in developing countries are getting significantly richer. One of the first things people do when their income rises is to buy themselves some meat.
The problem is, these trends - coupled with population growth (which I will be discussing next week) - mean there is unprecedented pressure on food supplies.
The FAO estimates that by 2050 the amount of food available in developing countries will need to double - which is the equivalent of a 70% increase in food production.
We would need a lot less if people stopped eating meat because it would require so much less land.
It is yet another powerful argument for changing our diet. So the question is: how can we get people to change what they eat?
We can try persuasion, working through some of the arguments, as I have here. But don't underestimate how difficult it is to change people's behaviour on this.
If you want a measure of just how tough a problem this is to crack, look no further than me.
I know the arguments pretty well (I hope you will agree) and I've experienced the health benefits first hand. But I will still be sitting down to a turkey dinner come Christmas.
So perhaps some gentle coercion might therefore be more effective. There is already a lobby for "fat taxes" - higher taxes on fattening foods. It is a short step from there to taxing foods that have an adverse impact on the environment.
But would any politicians have the courage to impose a tax on meat? They are reluctant enough to impose taxes on other, more directly polluting, behaviours.
There may be other ways - please use the comment box below to send in any ideas you have - but, in the meantime, I have two suggestions for determined meat eaters who want to reduce the environmental impact of their food.
First off, eat less meat - that's something my family is doing (though not this Friday).
The second is even more straightforward, actually eat the stuff you buy!
In developed countries a quarter of all the food that is produced goes uneaten, most of it no doubt growing mould at the bottom of all our fridges.
So here's a festive challenge: I want you to craft that limp carrot, half-eaten packet of cheese and the remains last night's pizza into a delicious Christmas spread. It has to be possible to rustle up something palatable... doesn't it?