Best thing in the world was always the Wimpey Coke Float, a creamy, fizzy cocktail of chemicals and animal fat that put just the biggest smile on your face. Then three decades or so ago McDonald's came to town, our backwater suddenly seemed a bit more urban, we more cool and Coke Floats so yesterday. Violent Barbie-pink shakes, so thick the sucking made your ears ache, were the thing.

Those were innocent days. Wobbly thighs and furry arteries were simply accepted accessories to carpet slippers and a smoker's cough come middle age. But after 30 years of Big Mac and Fries (786 calories), McDonald's is under siege. From rivals who do fast food with a bit less fat and a bit more class (coffee chains, bagel bars). From the guardians of the NHS purse who have worked out that the bigger our arses, the more we might be draining their resources. From fatties sniffing some payback in the form of lucrative lawsuits. And, perhaps most crucially of all, from Wall Street worried about one of the world's most lucrative franchises losing its crown.

This year, McDonald's recorded its first quarterly loss - £216 million - and the company lost £20 billion of market value since 2002. So now McDonald's has put itself on something of a corporate detox. New big cheese Jim Cantalupo (whose name happily drips with healthy fruity associations) has a plan and the hope is that a healthier McDonald's menu will lead to a healthier McDonald's balance sheet.

So now we've whole white meat Chicken McNuggets, fruit bags, organic milk, pasta salads for the mums and, according to this particular little press ad, 100 per cent beef in their burgers. The chips are down and third-quarter earnings are up (12 per cent). But a tighter focus on return on investment and a more considered outlet expansion strategy have surely helped rather more than the execrable "I'm lovin' it" campaign and these "we're not full of testicles, honest" press ads.

This Schoolboy Logic ad has a point to make about beef, but blimey it's laboured. This is an ad for a burger that costs less than two quid and takes less than two minutes to eat but you can practically taste the desperation to persuade us that it's good for us. It's the print equivalent of crafting a very heavy blunt instrument, writing "strategy" on it in big letters, and bashing everyone on the head with it. Often. Kid intently reading McDonald's Our Food book, and, as the copy tells us, musing: "I've heard there's all kinds of stuff in McDonald's burgers, but it says here that it's 100% beef ... not that I care."

So it's crude and it's awkward. But do I feel reassured about McDonald's after reading this ad? Yes, or rather I won't feel so guilty next time I plunge into a Big Mac at midnight. But the ad also makes me feel suspicious and a little uneasy. There's something rather sinister about this whole set-up: the big, corporate, global, powerful hand of McDonald's is just a little too evident to make me comfortable.

I think it's that book that does it. The fact that McDonald's has felt the need to produce what looks like quite a meaty little tome about its products, with a cover that's a little too evocative of communist Russian art. And the kid's reading it so intently, eyes almost glazed.

Ultimately it's too Big Brother, too manipulative. Too McDonald's, really.

One final worry: Wasn't it all the chemicals, the plastic unrealness of everything McDonald's, that always made it all taste so damn good?

And one final thought: In the time it's taken you to read this column, McDonald's has sold almost 10,000 meals around the world.

Dead cert for a Pencil? Not much chance of a nice yellow one to match

the arches.

File under ... B for beef, not bull.

What would the chairman's wife say? "Ooops, is that your strategy

showing, dear?"